carnage at the dyno

well today was dyno day and i thought it was going to be a great day, but it didnt turn out that way. engine came apart on the 5th short pull. only had 6000rpm on it at the time. not sure what caused it yet. still have to get it apart for examination. on #8 cylinder eagle H beam broke in the middle of the beam and both 8740 rod bolts are broke as well. looks like it took out 2 pistons the cam and the block. total pile of sh!t. also broke the pick up on the oil pump. looks like ill have to start over. it will be interesting to see what the cause was.

Ugh...

Ouch... the only consolation is better to find it on the dyno vs in the car.

Oh non !!!!!!!!!!!!!!!

What a deception !!

absolutely. the main reason i dynoed it.
https://youtu.be/hgoORq5ryWw

Very sorry to hear that.

it had about 45 minutes on it. put it thru a short break in as well. everything looked good, compression test showed all 8 had 195-200psi. checked plugs twice and got the timing dialed in at 35*. the carb was still fat and a jet change was next. i was using one of my new 750 ultras xp straight out of the box. my 850 had some fat issues in the midrange that we didnt want to mess with.

thanks. first time it happened to me. i think this was the 5th engine i put together and the first to explode. the number 8 piston looks like the pin was trying to come out the bottom. ill post some pics at the end of the week when i get it apart.

Does the rod look "sawed off" where it hit the block, or just broken. With both rod bolts broken, my GUESS would be oiling issue or it just broke a rod bolt. Usually when one just breaks a rod, the big end stays on the crank.

Watching video, it didn't really sound to be laboring before it broke. So maybe it just broke a bolt. Even beat all to hell, the bearing should show an oil problem if there was one

no it looks hammered and the rod journal is black. the rod bearings where calico and had the black coating so not sure if thats the coating im looking at or a oiling issue. the dyno operator said he thought the motor was down about 50hp at 6000 compared to what he usually sees. idled real good before every pull. had 55psi oil pressure when it broke.

Man, sorry to see that. You put a lot of work into that piece. I hope at least the heads are salvageable.

just took another look at the rod journal. does look like it got hot. wouldnt the #8 rod journal be the first to get oil?

yeah, i dont have those off yet, but we will see.

Sorry to hear about the failure!

Perhaps the crank was out of round? How do the other bearings look? What brand crank?

Be a good time to upgrade to a magnum block at the least.

Darn Dave, sorry about your engine.

That is awful. Sorry to see that. that #8 is usually the first bearing to cook on a sb with oiling issues.

VERY sorry to hear this Dave.

Totally sucks, sorry to hear that.

I can't tell from the picks where it got the block. Did it take out a pan rail or something else I missed?

It's hard to say about the oiling and does number 8 get it first. It is technically a constant flow system so once there is pressure if the pump can keep they should all get oil all the time. My experience shows 3 and 4 are the first not to get oil but that is usually about 8000 RPM.

Bad deal for you for sure.

Black crank throw...........it grabbed a bearing.

Main web looks cracked. Possible that happened first. Crank may be broken.

Rod didn't break.......it got sawed off

In the first photo, there is a notch in the bottom of the cylinder on the cam side.

why is that. i thought that was the first one to get oil?

thats from the rod. put a nice notch in it.

Im not sure why. Just what ive seen. Ive seen more number 8's jacked up than any of the rest of the journals.

havent looked at the other bearings yet and wont have time til this weekend, but why would #8 get the least oil.

dont make sense. i opened up all those passages. one thing i did do diffently this time was use single groove main bearing. will be going back to a full groove next time for sure.

I don't think I ever hurt number 8. If all,it did was notch the bores just sleeve it unless you have a bunch of blocks around.

didnt take out the pan rail, but it sure did a number on the bottom of the cylinder. pretty sure the block is toast.

I feel for your loss, get it apart, sweep up the mess and get after it again. Only thing that gets you over something like that is a newer better one, just like women.

That sucks man, sorry to see this.

How much rod bearing clearance did it have?

Sorry to hear. Hope things work out for you.

sorry to here that dave ,is it a 4340 crank and were they new rods or new rod bolts

what was the oil system; pan, pick-up, pump?

Wow, sorry to see this! Hopefully you can salvage the topend and get something going again soon.

Hopefully the block can be saved? Never done it, but maybe a Diesel engine repair shop might be able to weld up any cracks.

Sucks. Been there (not on dyno) but had one come apart at 7,200. Not much left and just had to start completely over.

Sorry to hear this.

a little over .002" (.00225)? and .0033" on mains. only thing I did different was I used a single groove main bearing. the block,crank and rods came from the last build I had and it went 8yrs. that last build had .002 on the mains and rods and never had a issue.

Sorry to hear it man, I feel your pain I lost one on the dyno about a year ago it didnt break anything but burnt the crank and one rod. It happened on the forth dyno pull and was also down about 50 h.p.. I would have been real upset if it hurt my R3 block as they are almost impossible to find. This is also why I dyno all my motors better on the dyno at the engine builders shop than at the track. It got back together and made even more power and torque than what I expected for what the combo is. I hope you find the problem
And build it even stronger and better.

Very painfull to watch Hope you get something back together soon

So vey sorry to hear about this, Dave. I know you poured your heart and soul into this one, Please let me know if there's anything I can do to help out my friend.

thanks for the good thoughts guys. once I get it apart and figure what went wrong or what I did wrong I will know what direction to go. I do have a 400 block I have been wanting to do something with. Ian the rods were used but I did have them checked at a shop and new 8740 bolts were used. right now I'm thinking Monty may be correct as it looks like it may have grabbed the bearing broke the bolts and sawed the rod in half. definitely a learning lesson here.

hey thanks a bunch man. that's cool. I appreciate all the help guys, thanks. I will not rest til I figure what caused this and I will not be making this mistake again.

Bummer Dave.. I have been in the same boat with
my Rampage.. it didnt blow up but did tear up
the bearings and a little on the crank... good
luck with it

That sucks for sure.
Usually, if there is a wasted bearing and/or a darkened/blackened journal, that's what caused the failure.
Why that happened in your case.......that's what you need to try and figure out.

My friends "good" stocker motor ate a rod bearing on the dyno last fall, and that's a motor that has been run for years, and been on the dyno many many times.
The power was down just a tick and it wasn't repeating as good as it usually does, but that thing uses a Q-jet, and those can be fussy. We did a couple of carb swaps, seemed to be making some progress, and actually got to a point where it made the most it ever had.
We took a break and went for lunch. After we came back and resumed testing the power was down about 15-20hp. The first pull after the motor has sat for a while is usually down a bit but not that much.
Oil pressure seemed a little low after the pull. Loaded the motor to make another pull, TQ looked like it was way down....... And I just shut it off. I knew something had gone away.
Pulled the filter and took it apart(system 1), saw some filings.....we were done.

I don't recall which rod bearing failed, but all the rest of the bearings looked perfect.

thanks Mike. i will get it figured out. if the block is scrap i think im gonna start on the 400 block and sell off all my small block stuff.

Sorry to hear. Were the rod size checked after the bolt swap?
Doug

same scenario here. did you figure out the cause?

yes it was checked and I checked the bearing cleances several times. I was alittle concerned with the rod bearing clearances so I called hughes since that's where I bought the calico coated rod bearing. they were not concerned with .002" said run thinner oil. I used gibbs 15/50 because the mains were .0033. the rod bearing is wadded up and hard to read.

Rod and main clearance is a balance of those clearances, the top end oiling and oil weight.

.0033 on the mains is fairly common. Then going .002 on the rod. With aluminum rods fine sense they grow. May have been to tight when considering it's fed from the main. Only #8 is fed from #5 main. Where as the middle journals are feeding two rods each. The rear main wasn't upside down was it? Look at the #5 main bearing.

I will check that out, but I don't think it was. I'll get it apart Sunday and see if I can make heads or tails out of this mess. Thanks

Sorry man, that gives me a knot in my stomach to see. Hope something can get salvaged.

Like others said, next time use .003 at least on the rods. Better.005, than .002.

Standard rod bearing on a 2 under and full groove mains is what I have in mind.

Just personally, I don't like full groove mains. I tried them several times years ago and they never held up, or looked as good as a grooved upper with a solid lower. The HP King bearings have been for me the best at doing the work. they have a ton of taper in them, that will help deal with either a poorly machined, or high power flexing crank.

I been studying hard the oiling in my stroker I am building and it seems the full groove would help the rod bearings live longer because they have access to pressurized oil when the cylinder pressure is highest. The 1/2 groove only sends pressurized oil to the rod on the bottom half of the stroke. Weather or not that amounts to a hill of beans under dynamic conditions I could not tell you but it does seem odd they do it that way from the factory.

In order to keep more oil on the crank on mine I drilled smaller oil feed holes in the cam bearings as they are getting fed right off the oil going to the mains. When everything is done right in a SB oiling don't seem to be a big issue from what I have seen. I almost always use standard volume pumps and don't seem to have much issue getting enough pressure.

I shouldn't of had this problem. Same block with all oil galleys opened up, same crank and rods. Used full groove on last two builds and didn't have this issue. I use half groove and boom!

Sorry to hear Dave, I know you were excited to get it running and try the TR eventually.

Man the is a real bummer. Hopefully the replacement isn't too painful

That is NOT what anyone ever wants to see happen on the Dyno.

SUX man!..

The issue is the oil timing is wrong on these engines. You should have full oil pressure to the rods at 70* ATDC and that is IIRC but it is close to that. That's why a Chevy doesn't need full groove mains. The Chryslers get full oil pressure way before they need it so the full groove mains helps that. Seems to be worse on the SB but it is wrong on both. The higher the engine speed, the worse it gets.

There are only two fixes for the high rpm stuff (unless you get a block that has the oil passage in the correct location).


One is have a crank drilled with the oil hole turned counterclockwise. The other is more complicated. That is the only way I know to correct it.

I still haven't given up on the SB yet. I was offered a good 360 block from a member here. Just pay freight. There are a lot of good guys on this forum. I'm interested. I will need a set of rods and 2 pistons a rebalance and a cam. That's doable. I might even have the crank ground for more stroke. Will see. Thanks again guys

Dave you're making me rethink using 1/2 groove mains on my 434. I had to order a set of .001" unders so I have the other grooved half. My rods are 2.00" and the clearances are .0023-.0025" using King aluminum rod bearings and King mains.

well, i'm not certain what caused this yet. I will get it apart and examined sunday and go from there. I may change this build up alittle with possible added stroke and more cam.

I wouldn't be so quick blame the mains, or crank needs cross drilled, or anything else. My first thought is it was too tight

Dont forget to look into this.

Would not be surprised if your problems are related to this, rods dont try to pul a pin out of the piston without reason.

Obviously it's important to have adequate oil delivery to bearings, and to have proper clearance which will vary depending on the engine and type of usage.

One thing that is often overlooked is the bore of the rod must be round, straight, and sized properly. It's about as important as round and true crank journals and round and straight cylinders. When the bearings are encapsulated in the assembled rod, if the bearing shells are not evenly and tightly contacting the rod bore they can walk around, and they also heat up significantly more because the poor contact between the bearings and rod doesn't transfer heat away from the bearing very well. The bearing shell is then prone to distort from excess heat and lack of support, which usually reduces the oil clearance, which is the beginning of the end.

That may not be what caused your problem, but it's very possible it was. If bearing to journal clearances are on the tight side that's 2 strikes. A lot of rods are honed with methods that are "iffy" and when not done correctly make the bearing bore bell-mouthed. I always inspect and measure the rod bores. On engines that have some run time on them you can look at the contact surfaces on the back of the bearing shells and the bores and see how well they fit.

Real sorry to see this Dave, i've put street stuff together but would rather have a motor done by a professional when it's going to see a lot of rpm and has high cost parts.
Mick

Believe me that thought entered my mind when I seen oil gushing from the bottom of the pan. I'll see how I feel about that when its ready for assembly.

I will never use another set of used rods.

Looking at the broken parts that fell out I think your right. Too tight and not enough oil.

There was killer rotating assy on here a few weeks ago. Killer rods, and Killer stroker crank, don't know your cash flow, but it was reasonable.

Here's another thing to think about. The last two builds(408) had .002 on rods and mains and never had a failure but had full groove mains.

You said rods were used and new bolts installed. Were big ends checked for size and roundness

On big blocks there's a wide groove bearing and a narrow groove bearing. Both are full groove. I use the narrow groove.

yes they were checked at a machine shop. i checked bearing clearance again before assembly.

if i remember right i believe these calico bearings were a narrow bearing. i used a federal mogul main bearing.

i'm also second guessing the oil mods as a cause. i have heard the guy that posted those his engine also came apart. not saying thats the cause, but not sure i want to perform those mods on next block.

I doubt that clearance was too tight, but I don't remember what oil you used. I am about ready to fire mine off and it has .0021 on the rods and .0024 on the mains. I'm going to use a 5w30 oil. If yours was too tight I'll be screwed just like you.

I think a lighter grade oil and FGM's and you will be ok.

joe gibbs xp4 15/50 non synthetic(breakin). like i said last 2 builds had .002 on rods and mains with full groove and using 20/50 amsoil, no issues. i had 100# oil pressure when first fired up, 75 when it got warm and 55 when it let go.

I had a big block come apart on the dyno years ago. It had good oil pressure when it spun a rod bearing. We never figured it out exactly but part of the problem in my case might have been poor oil volume. Pressure was high but volume might have been too low. The other issue in my case was tight clearances and heavy oil. I used some 20/50w which might have contributed to the problem. I was also using a fairly inexpensive connecting rod which might have been part of the problem. Hard to say when just one fails. Could be something about that particular rod or it could be something about the oiling to that one rod.

I think .002 is fine with high quality machine work but the taper side to side, roundness, big end bore... all need to be very acurate to get away with it consistently. If you machine shop can't deliver very high quality machine work than better to have a little extra clearance.

Your oil pressure was a little high, especially at idle, I wonder if you had a restriction somewhere?

Also rule of thumb for oil pressure is 10psi per 1000 rpm , 55psi at 6000 is a little low especially with that thick oil .... but that could have been the bearing going away at that point ?

What oil mods did you do Dave and why not try 10-30. I switched over from 20-50 years ago and my engines love it.

You also may want to step up to SPS2000 (ARP)rod bolts. Cheap insurance.

I was always under the impression that when the bolts were changed the rods got resized.

I have run coated bearings that tight without any problems, and at higher RPM. I was running 10W-30 oil, but 15W should have been fine. Mine have all been big blocks with full groove main bearings to improve rod oiling.

It does not matter what the first number is when looking at the grade of an oil. I don't remember off the top of my head but the winter grade is checked at 32* and colder as the number goes lower. He was still using a 50 grade oil. I don't know where Gibbs oil is blended at, but if it is on the high side ( so almost a 60) that oil was too thick for that clearance. The spread for any given grade of oil is very wide. Cheap oils run in huge blends can vary in grade from lot to lot. One lot may grade at the top (almost a 60) and the next lot may be on the low side (almost a 40).

There is a reason some oils are $8.00 a quart and some are $24.00. It pays to spend some time researching who these companies are, what base stocks they are using (probably the LEAST important part of any oil...but the company can save $$$$ using a cheaper base stock), what the additive pack is and where they put the oil in reference to grade.

When you start talking about squeezing down clearances and things like that, or using alternative fuels, it pays to do some research. And get on the phone and talk to themes guys. Every oil guy I have ever spoken to has been very frank about the questions I ask.

I think the single groove main and the plugged driver side oil galley contributed to the high oil pressure.

I called Gibbs and told them the combo and bearing clearance and they recommended the xp4 15/50. So that's what I used. I have always used a 20/50 because of all the internal leaks. Lifters being the biggest leak.

15/50 is only 15 vs 20 when cold. Hot 50 is 50. Personally on non power adder stuff i see no reason not to run 5W30 unless it is a combo that runs a lot of oil temperature.
Doug

Sorry to read this.

It's a shame, I just let a stock bore 360 go for a song because I was tired of looking at it.

You can't fault a guy for doing what you are told. I tried to see where that 50 Is supposed to measure at but they don't give it out. Or I just can't find it.

I don't think many other oil companies would call out a 50 for those clearances but I could be wrong.

I had 20-50 VR1 to use in mine but after soaking the roller lifters in it and seeing how thick it was went with Brad Penn break in oil on the dyno. I'll use their 10-30 now that it has been ran.

I can tell you this, when using 20/50 hot oil pressure was 15-20 at idle and 55 thru the traps using full groove bearings. I didn't know what to expect for oil pressure on Dyno with single groove and plugged oil galley Dr side. Thought too much would be better than not enough or too low.

Oil mods were open up all oil galleys. 1/2 and 5/16 from oil pick up thru main rear cap to plugging the Dr side galley which only feeds the lifter galley.

Dave... those pressures are VERY high for those
clearances... I have never had over 70# cold and
25-30 hot.. when pressure is high you are reducing
the flow.. remember pressure is a restriction in
flow... I use the half groove mains and turn higher
rpms... but I do use .003 and .003 on my clearances
on all my junk... I balance out my oil pressure once
I see what it is both hot and cold... but I wouldnt
make a dyno pull or a pass with the pressure you stated

15W/50 is NOT like straight 50W. Straight 50 is like syrup when it's cold. To put it simply, or at least how it was explained to me, was that multi viscosity oil, the first number is basically the Winter or cold viscosity, with lube qualities of the heavier weight when the motor reaches 212*. For the oil to actually get to the 50W viscosity takes the high temps. This is done with "viscosity modifiers". The cold or Winter viscosity number is based on how hard the oil is to pump through a given orifice at low temps and has to meet pumping pressure requirements based on temps and test orifice size. So what does all that mean? Simply put the 15W/50 oil MUST pass SAE J300 standards of a straight SAE15 to be labeled as such, as well as passing the 50W SAE J300 standard at 212* So that said, based on average dyno room temps and his bearing clearance, no way should 15W/50 be too heavy when cold. Factory motors used to run as tight as his and straight 30 was what most everything came with back then and they weren't grabbing bearings, even in extremely cold temps.

I don't know what caused his issue, but I highly doubt it was the viscosity of the oil, the lack of full groove bearings, or similar.

Of all people, the ones at Gibbs, who he called, should know the characteristics of their oil.

I dont care what the viscosity is.. his pressure is
HIGH... pressure is a restriction in flow... PERIOD

I understand that......but some were saying the 15W/50 was like 50W when cold and it is NOT. Would you think straight 15W was too thick given his combo?......No and neither would anyone else and that is the SAE standard that 15W/50 oil MUST meet when cold. My point was that is wasn't the oil that caused the problem.

He said he had .002. Well how was that checked? With plasti-gauge or with mics. And if mics were used, was it only checked 90* from the parting line in a torqued rod, or in several places. The rod could have been out of round, or the crank pin had taper or wasn't round. .002 in one spot, doesn't mean it had .002 everywhere. I still think it was just tight for some reason. If you want to run em tight, that's fine, but it better be right everywhere

I know when I tube the lifter galleys on my small blocks I double and triple check to make sure I redrilled all the needed oil passages and followed the instructions to a T. To make sure I dig out my old mopar manuals just to double-check I didn't forget something.

Is there any way to tell if the coating delaminated?

If it wadded up it only takes a millisecond at speed for the crank to grab the bearing and just a few more to go boom.

Kevin

Well to start with the eagle crank had bad machining on the journals and it showed on the previous build when torn down. The journals were wavie. So my machinest turned all journals and checked rods for out of round. I left that up to him as he has built many circle track engines and has a good rep. He mic'ed the torqued rods and journals and gave me the results which were .00225. I remeasured 90 degrees to parting line on rods and measured journals and found the same measure upon assembly. I used a dial bore gauge and mic. I figured good enough.

Good practice to measure rods in 3 places to ensure they are not out of round after you crush the bearing. Also, rod can be perfectly round but big and NOT crush bearing enough. Will measure right at parting line but not sides. Same if rod is small and has too much crush.

Dave understand that at just about 70 psi the pump
is blowing off on the by-pass.. thats not flow to
the engine...all the pumps I have checked the by-pass
on blew of real close to 70 psi + or - a small amount..
so all that extra pressure you have will hurt the flow

I see. Mygoal was to have 60-70psi hot at rpm but, It didn't turn out that way.

OK. Well I gave all my parts to a machines and had faith he knew what he was doing. He gave me the ok everything is good and I took the parts home and measured bearing clearance for piece of mind and assembled. The guy has a good rep for machining and engine building. I guess ya really don't what quality of work your getting til ya have a failure.

I know what ya mean.. I've been there... my one engine didnt
make a 1/8 mile before it let go... luckily it didnt take out
a ton of stuff.. a lifter let go.. that took out 1 head, a
couple of pistons and a cyl bore... a sleeve on the block
with a new head were the big parts.. that was a quick $3500
for that

You dont pick an oil based on the winter grade number unless you are running in sub freezing temps.
Viscosity is based on oil temp.
His oil acted like a 50 grade oil when at operating temp.
That seems heavy for his clearance.
I don't use Gibbs so I can't say why they picked a 50 grade oil. I would have used a quality 30 grade.
The oil timing is off on these engines. At the speed the OP is turning he needs a full groove bearing to get oil to the rods on time, or close to it.
The only fixes for high RPM (over 8k) are have a crank drilled to the correct oil timing, but I have never had it done.
Or, you have to bring the oil to the crank in a different place to correct the timing.
And that is a whole nother thread.

im not going to do that but how do you know where to put the holes in the crank?

ok, so let me get this part cleared up. with bearing clearance at .003 on main and rod with full groove mains what would you suggest for oil viscosity in this combo?

Forget that crap... SB mopars have been turning HIGH
rpms for YEARS with normal cranks.. the most I ever
did on the crank was elongate the oil hole some.. you
can do that with a file or have the crank grinder do it
(they know what I'm saying on that).. but its just the
slot across the oil hole.. as I said before.. I have been
9600 rpm and its still together.. and I sure dont do anything
magic

You have to have it done when the crank is made. I heard that one from a known Comp guy who did PST and dabbled in PS. I didn't do mine that way. But I'm not about to go into the detail of how I fixed mine because it would take an hour to type. If you really want to know, PM me and I'll do it that way.

Mr. Pbody would be one of the only guys I know that can turn a SBM that tight on regular oil timing. Very few guys do it in the first place. Even fewer do it with any level of success.

As for oil, I only know one brand. I wouldn't want to tell you a grade for any other oil. Like I said, there is more to oil than base stocks. It's like how they grade an oil. It can pass as a 50, but it might test on the high side of the grade and almost be a 60. You can't tell the difference, but the engine can. So it is very brand specific.

I may spend some time tomorrow and see if I can find the actual specs of the oil you used. If I can find that, I can see where they blend the oil as far as grade goes.

You can't correct the oil timing with file. And the oil timing is off, by a mile. All you need to do is stand a sbc next to a sbm. Even Ray Charles can see the timing is off. And you need the cranks too.

OK . in the past combos I used 20/50 brad Penn,valvoline and 15/50 amsoil with .002 on mains and rods and never had an issue.

I'm not trying to correct anything.. it just give
it more area for the oil once its out of the hole
to hold oil.. I bought a old PS truck crank and that
is what was done to it.. then I had another turned
down and they did it for me

Not that I know anything but this is what I was thinking reading through this thread, I'd reject the idea that it was too tight, too thick oil, etc. I'd think it was too out of round, was starved for oil, or simply didn't have .002 clearance...

I wouldn't want a 50 weight in an engine with .002 clearance, but people put 50 weight in tight engines all the time. Or engines that they have no idea what the clearances are, factory stuff, etc. I've put 50 weight in old worn out oil burners, who knows what the clearances were, but I wound them up tight and it was never an issue. Maybe they were just loose. But if 50 weight with .002 clearance was an issue that was going to grenade a lot of engines we'd be hearing about it a lot more often...

How comon is it that a bearing/oiling isue tries to pul the pin out of a piston?

I cant say that both would even be related .. if the
pin doesnt get oil they tend to seize the piston and
then end up spinning a bearing

I'm thinking after the rod bolts broke the crank hit the rod and caused the damage to the piston. I don't think the carnage started with the wrist pin.

So perhaps this was a wrist pin failure? The rod bearing failure being a secondary result?

This engine has an Eagle crank. While I have not compared a SBC and a SBM Mopar crank from Eagle, I would imagine that Eagle uses the same "high speed oiling" arrangement in all their crankshafts, regardless of brand of motor. The way a crank is made, you can move the timing "some" but it isn't a huge amount. So while it may be true that factory Chevy and Mopar cranks may differ in timing, I would think aftermarket cranks are drilled the same. Would be easy to find out........all you have to do is ask them.

BUT........that isn't the problem here. SB Mopars been running for years with factory drilled cranks.

As far as the oil, some need to read up on how multi viscosity oils are rated, tested and really work. The oil in question here would not have taken on the viscosity characteristics of 50W until the oil temp reached 212*. And anybody who has ever drained some HOT, even straight 50 from a motor, knows at that temp, it is not all that thick

Looks to me like you had a clearance issue, or the crank journal or rod big end was out of round. Don't see a big mystery here, lack of oil film on that rod...

So, only one rod bearing didn't like the oil? The other bearings look good?

The only way to know for sure is to have what you were using tested. Like I said, the oil grading system is very wide. You can buy a 50 that is very close to a 40 or it can be very close to a 60 or anywhere in between.

I tried to find numbers for the oil you were using and I can't. I may call them and see what I can find.

125 replies and quicktree hasn't stopped in to bestow his knowledge yet...something is wrong!

We at least need to use the correct terminology. There is no such thing as a multi viscosity oil. They are multi grade.

Again, the oil timing is way off.that isn't the issue hear, just try to help people learn. As RPM goes up, the more the timing issues show up.

What the oil acts like drawing it is irrelevant. It pumps and resists flow like a 50 or it wouldn't be graded a 50.

EDIT: I have looked at Eagle cranks. And Scat cranks. They have the oil holes in the factory Chrysler location. That means the oil timing is off. If you want to argue oil timing and how critical it is, take it up with David Nickens. I had several long discussions with him. He isn't stupid.

A SBC is not an excercise in good oiling to follow, they got some messed up junk coming down from the cam then to the lifters and then the crank gets the left overs but somehow they live for a while, that is why they like to use high volume pumps and such to ensure enough pressure is left over from everything else to keep the crank lubed. Sure a SBM has timing issues but based on the guys like p-body and others and the SBC guys with that crappy oiling set up turning serious RPM it just don't matter. Centrifugal force is going to keep the oil flowing out of the crank toward the rod bearing even when the pressure is blocked for a split second.

I don't think he had a oil quality or viscosity problem, I have seen guys running 20-50 in brand new cars that come with VERY tight clearance and it don't hurt em, I run 0-20 in all my cars anymore and no engine trouble that did not exist when I bought the car. It was something wrong with the machining, out of round, too much taper, twisted crank...

That's simply not true. It IS multi viscosity and that is accomplished by VIIs which stands for "Viscosity Index Improvers". Grades or weights of oil are defined by their viscosity. Multi weight oil HAS to pass both SAE J300 test parameters for which it is advertised to be. In this case the oil has to pass BOTH 15W cold tests and 50W hot tests to be classified as such.

Below is from Bel-Ray



The SAE designation for multi-grade oils includes two viscosity grades; for example, 10W-30 designates a common multi-grade oil. The first number '10W' is the viscosity of the oil at cold temperature and the second number is the viscosity at 100 °C (212 °F). The two numbers used are individually defined by SAE J300 for single-grade oils. Therefore, an oil labeled as 10W-30 must pass the SAE J300 viscosity grade requirement for both 10W and 30, and all limitations placed on the viscosity grades (for example, a 10W-30 oil must fail the J300 requirements at 5W).

Wasn't referring to the ENTIRE SBC oiling system, only how the crank is drilled. The crank is drilled to provide crank pin oiling at 60 before "max load" on crank pin.

What I think not everybody understands about multi-grade is that warm 50wt will flow easier than cold 15wt. But cold 15wt flows easier than cold 50wt, the same is true when theyre warm. You need enough film strength and clearance to prevent metal to metal contact. If parts flex even more clearance is required. The thinner the oil the higher the flow at a given clearance and temperature. More flow equals better cooling of the part. Higher temp equally thinner oil, too thin or hot and you lose load capacity. It's all a balancing act. My theory in this case is either the clearance tightened up or we had lack of flow, providing nothing broke at the onset. The temp and film strength would be the same for the other 7 rods. Maybe after teardown we'll find a obstructed rod feed galley, other rods that are out of round or a spun #5 main? I still like thinner oil and more clearance, but doubt if 50wt or if it had actual .002" clearance caused this failure. My 2 cents
Doug

Amen brother!

I get this Monte. One time they say viscosity and then they say grade. Viscosity is temperature referenced. Grade is what they are rated at. If you take a 50 and measure it at ambient it will be closer to the winter grade number. But the viscosity is related to temp. At 212* a 50 is a 50. At 240* it's still a 50, but its viscosity is much thinner. Still a 50 though.

Exactly, and maybe I wasn't clear enough. Monte says it's 60* degrees where the oil is timed at. The point is at the exact time, the oil hole in the crank had damn well better be lined up with the feed hole in the block so Full oil pressure is going to the rods. On a SBC these two holes are lined up at the right time. On the Chrysler they are not. It's a big deal as the RPM's go up. That is all I am saying.

I'm sorry but you are wrong. I can't say it any nicer than that. If you rely on centrifugal force to oil the rods, you will kick out 'two rods. Usually 3-4 go first.

How many small block molars have you built that made horsepower over 8000 rpm? I have done it. Many say they have. I know I have. I know the results. They are not good. You MUST fix the oil timing issue or it will fail.

I wish I had never mentioned oil timing because it is off topic to the OP. But I felt it was relevant. There are many busted blocks from oil timing issues. The OP didn't have that issue.

I know one thing, it ran out of the pan like water.

I will know sunday when i get it apart. dont have all my tools here.

Dave did not have a problem turning 9000, he had a problem at a much lower RPM where engines have lived a loooong time without fixing the oil timing issue. My comment about centrifugal force was just speculation on how they live at 6000-7000 RPM.

Don't worry about bringing it up, I was the one who steped in it not you.

Not a oil prob. part failure or clearance prob.
either way it be junk know. hope you can save as much as you can.

Me too. I think the block is saveable as long as its not cracked but I will be using a different block next build.

You guys also got to remember the first fire up of a new motor generates a lot of heat as all the parts "get introduced" to one another, even when everything is precisely machined and fitted. Those tighter .002" Main clearances (as Monte correctly points out) means that you have much less margin of error on any high .0001 or tight spots. Also the 360 has a bigger main diameter than even a 440 so bearing speed and heat is higher, so combining that with a tight clearance is something to watch carefully....even under normal non stroker loads. Also....I don't think most people realize how much things move around inside a cast iron block, and how much side loading comes into play when you load a motor up. I'm assuming a motor like that was line honed? I have to suspect somewhere the (too tight on too tight) 'tolerance stack' might have bit you. More oil clearance (say .003 vs .002 )also means more (50%) hydraulic cushion around the crank as well as more volume passing through with less restriction, it also allows the oil to wick away more heat. The other key component to oil (other than friction reduction) is also it's surfactant (surface cooling) qualities.

Again, I'm so sorry to hear about this.

Thank you. That's behind me now and I'm in the process of building a better engine. I can salvage some of it. Do you think I can reuse my piston rings? Mahle 1mm steel rings, 45 minutes run time.

Dave, what was the oil temp before it let go?

Assuming the notch in the cylinder is the only block damage.......sleeve that hole, get a rod and piston.....fix crank and carry on. If the crank is standard now, grind it .010 and get some more clearance

I agree. Use as many parts as you can. A .010/.010 or a .030/.030 crank is just as strong as it is standard.

You can reuse the Pistons if they don't have a bunch of junk in the skirts and I would reuse the rings if they pass the eye test.

A sleeve in a bore is not a bad thing. In my time I have set literally hundreds of sleeves. Zero issues.

Save what you can.

When I have my cranks ground I always tell them .011, .021, .031, ect ect. Its always worked for me.

That's what I was going to say. Don't just tell them "grind it .010". Tell them to grind it to where YOU want it. You do that by measuring the main housing bores and rods with bearings installed and torqued. Get those sizes and then have the crank ground to the number that gives the clearance you want.

If your crank grinder says he can't get it that close.....find another one that can

I always say .0005 under minimum. Then I size the rods and main line for the clearance I want.

Removed the heads today. Not sure I found the issue, but I did find a issue. Both intake and exhaust valve touching the piston on #8 only. Now I did check VP clearance but on 1 and 2 cylinder only(.130) on both. I did check deck height on all cylinders and I had .005 in the hole on all. The valves have not been checked but do not look bent.

Now if you remember from my build posts I used a .030 head gasket on pass side and a .036 on the Dr side to get the compressions equal. Do you think the piston could of hit the valves after the rod broke?

Yes if none of the other pistons on that side show any signs of valve contact. The only other explanation is that the #8 rod was long.

Once the bearing clearance went away and the rod let go it smacked the head and valves, that is not the cause of the issue. If it was you would have only hit the head as you had way more clearance from the valves, the damage to the head/valves is a result not a cause.

When the rod broke, piston stopped moving, rest of motor did not. Valves opened against a stationary piston that was at the top of bore........or as cap was coming apart, rod got "long" and smacked head. Either way, affect, NOT cause

Kinda what I thought. Looks like something was in the cylinder. Left marks on the piston and head. I'll know more tomorrow.

I see what you are talking about. Maybe the extra load on the bearing from sticking something between the head and piston caused too much load for the oil film and made the bearing grab.

The good news is the heads of the valves are still there and you save the head.

Did the piston hit the plug? That could explain the marks on piston if it knocked the strap off or broke the porcelain.

Would have to be something really big to hit the piston hard enough to hurt a bearing. That's very minor, whatever got up there

First thing we did after the failure was pull all the plugs. They all looked good. Don't see any indication Of piston hitting the head. Something was in there but hard saying what.

What I see looks like the valves shaved some of the piston out in the radius of the valve reliefs. Like the piston was cocked in the bore when they hit it.

OK maybe that's it. Do you think wiseco would build me 2 pistons or will I have to buy another set of 8? A member here is sending me a 73 360 block with the 4 bolt main conversion short fill line honed and a 4.040 bore. If I can get just 2 pistons made I can get this back together pretty quick at low cost. If I have to buy a whole set I will start on my big block project.

As Monte said there is almost always valve to piston contact when the rod breaks. Replace those valves. How does the #5 main look? no need to buy an entire set of pistons. two will probably be a little more costly per piston.
Doug

Sorry to see the carnage

Yes, your going to be replacing some valves also.

Is the piston still loose in the bore? What's the ringgap?
Any damage marks on the cylinder wall from a possible piston seize?

I've once seen an engine where the camshaft had broken in half, piston ringlands were cracked and the rod was broken with some crank/bearing damage.

The shop who put the engine together thought they had gotten a badly cast cam and tried to go after the cam company.

What they didn't (want to) see was that they had built the engine with too little ringgap clearence, which caused that particular piston start to seize up high in the bore, causing excess stress on the bearing for a while and finally snapping off the rod and bolts as the remains got pulled down by the crank, and while that happened, the still rotating cam was trying to open the valves, which broke because the valves were blocked by the stuck piston.

Its hard to believe what can happen to some of these engines. My Friend bought a chevy small block (short block) from a well know Ohio Company and He made 2 passes on a test n tune and on the 3rd one I ran over to the fence at half track to watch. He heated his tires and before he could stage his headlights went out and they pushed him off the track. We thought at first his battery died and it shut off but I did some checking and it was locked up. The piston EXPLODED. They wanted the engine back for an investigation and the piton parts were sent to the manufacture. I read the 6-8 page report and it came down to dirty engine assembly work. They sent him a new short block and its going on its third season.

I don't see any marks on the cylinder wall. Pistons moves with ease. Ring gaps were .020 and .024. Yeah if I can get 2 matching pistons I will put this back together. I would think $100 ea. They were a total custom deal.

Check that rod journal for heat cracks before using the crank again

Adney Brown with be getting the crank.

Glad you can save the engine with minimal costs.

Wow Dave, sorry to see the failure.

yeah, but i'm hoping to get something together soon. I dis assembled the short block today. All bearings were starved for oil. Removed plugs in the block and all oil galleries are clear. All bearings were in their proper places and everything was tight. I was scratching my head trying to figure what went wrong. the pick up had 1/4" of clearance from the bottom of pan. I thought maybe the purolator oil filter was the issue, but dont think so. I took the oil pump apart and found what looked like a bur riding against the pressure valve. If it was holding that shut not sure enough oil would get thru. heres some pics

I slid a red electrical prob in there so you can see the bur.

Any ideas? Im ready not sure what caused all the trouble here.

with all the oiling mods i shouldn't of had this issue.bearing clearances were plenty. looks like the rear suffered the worst.

No expert here (not even a novice) but all those bearings look like they were starving for oil. You could have a blockage somewhere?

maybe someone can school me on how these oil pump pressure valves operate.

Are you sure ALL of the shavings from all your oiling mods got flushed out of galleys and passages? Did you hot tank and flush/brush clean after doing the mods?

I'm guessing from the photos you posted that the rod bearings start with #1 on the left and the mains start with #1 on the right? What exactly did you do to the block?

correct on the bearing orientation. opened up all 1/2" and 5/16" oil gallery. plugged dr oil gallery on #1 main. this was done before the block went to the shop and it did get a cleaning there. their is a plug in the large oil gallery under the rear cap. what is the proper orientation for that plug? how is it possible to have 75psi oil and not get enough oil to bearings?

I also ran brushes and compressed air threw every gallery before i assembled it. that block was clean no doubt.

Dave IIRC the plug is driven into the block between the passages from the pump and the main feed passage. If it was driven to far it could stop or restrict flow to anything past the #5 main. The cup side should be facing down. I suppose if it isn't driven in deep enough it could restrict flow to the #5 main.

If you remove the threaded plug from under the oil filter and shine a light in the port you shouldn't be able to see the plug.

Dave... didnt you say you had 100 psi in your
early post... anything over 70 is just getting
dumped back.. it doesnt go through the block..
and your pic of the relief valve.. I'd bet that
happened after it came apart.. a piece hung that
valve open.. have you looked at that chunk yet

If the crank is std grind it .011 U.S. and get some more clearance.

I agree with streetwise, the stacked size variances got this engine. The thickest bearing wound up in the smallest rod on the largest journal on the crank.

did that and did not see the plug. the cup points to the bottom of the block. would their be any possible way the oil pump valve could cause low oil flow but still show high pressure?

yeah Mike, 100psi on start up, 75 warm and 55 when it came apart.

If it was stuck open you would have low pressure

well, then if the mains had .0033" why do they show signs of low oil? doesnt seem like they would have got hurt at all.

what would happen if it was stuck closed?

Your oil pressure gauge would be be pegged high and blow up the oil filter.

Are you sure the pick-up tube didn't un screw and sit on the bottom of the pan?

ok, so that rules out the oil pump.

Nope.. no way... unless your gauge is reading real
high.. check it for calibration/accuracy

yes, in fact the pickup was knocked off the oil pump breaking the pump when the failure accured.

The pick up cant come unscrewed.. the crank would hit
it.. and you say it broke the pump at the pick up.. so I
would assume the rod did that.. you also say it had pressure
when it let go.. correct

yes, looks like a rod hit it. 55psi when it let go.

You had a ton of oil pressure and you spun the #8 rod bearing, all the bearings look oil starved. IMO your clearances were to tight.

Out of curiosity, did you pull the valve covers after it went down? Was there much oil laying the heads?

they may have been on the tight side on the rod, but the mains had plenty. why would they show signs of low oil?

The 55 psi when it let go rules out the pick up
and pump

They were tight too. How did you set up your bore gauge?

i have no ideas left at this point and i cant put a sb together til i figure out what happened here for sure. i am not totally convinced the bearing clearances were the cause. last 2 engines i put together both had .002" on mains and rods and ran 20/50 in both. no failures and had the same pump. last engine went 8yrs street/strip.

with a mic. my machine shop measured everything first and i just confirmed their measures.

I don't know Dave. If it had .002 on the rods, .003 on the mains and enough oil pressure I can't see why it would fail. The push rods and adjusters look ok?

That's dangerous. You should use calibration rings or at least size blocks to set up a bore gauge. How did the machine shop set up the bore gauge?

I have a lot of experience using bore gauges and using a mic is just not very accurate. Way too many variables.

Did any of the lifters pop out? Hard to imagine ALL the bearings being to tight and being burnt. How long does it take to burn them before spitting a rod? Where was 55 # of oil going? My thinking is the rod bolts let go, oil pressure gone, then everything else followed. I could see one being to tight, but all of them? Did the crank spin freely by hand when installed? How did it spin after the rods where in?

It blacked the crank. It was tight or had no oil. Stacked a bearing and then broke rod bolts.

All the mains look fine except #4......need to figure of why THAT is and you might discover why that rear journal had no oil, or at least less than rest.........BUT.....ALL the rods were tight or had low oil volume. The pictures tell the story

It looks like the number four main had crankshaft run out on it What rod bearing failed first? If was #6 or 7 maybe debris from the #4 main bearing started all of this
BTW, sorry for your loss. I hate new parts that break

not sure how the shop set up their bore gauge, but i got the same numbers they had.

#8 went first and 7 was on its way.

If you could see the mains in person, they look just like the rods to me. ok, well then the mystery is solved on this engine failure, but now the mystery is why the other two engines survived with .002 on both rods and mains. The last build used the same block(without the oil mods), same crank, same rods and the same oil pump and used 20/50 most of their lives. only difference being both other engines had full groove mains and were broke in on 15/40 diesel oil.

Is there anyway you can pressurize the oiling system and see where you're getting oil to (or not)? Could you have broken through on one of the oil galleries and bypassing it somewhere else?

Sucks to see all the carnage man. I'm not much help in saying what caused it besides I'd bet it a culmination of several things vs just one thing causing this issue.

FWIW too, since Rotella went to the CJ-4 classification some 15 years ago the zinc content went way down. It and VR-1 still maintain about 1200ppm so using it vs what you used I doubt would of helped. The zinc content goes away with time and is broken down at your wear surfaces. Higher numbers means it lasts longer, but not necessarily meaning it's better. We're lucky in this day and age we have a lot of great oils to choose from.

Good luck.

i did pull the plug on the lifter gallery and blew compressed air in all the main oilers and could feel air coming out.

IMO all those bearing look pretty ugly to me for a fresh deal for sure. All the rod bearings show lack of oil film on them, 8 just was the one that went first. None of them look good to me at all. But maybe it is just the photo

your correct, non of them look good. Just got off the phone with hughes engines. Dave suggest there was a blockage or leak some where. Said those bearing clearances nor the single groove bearing main bearings or the heavy oil the cause, but would never suggest to run heavy oil.
Called wiseco and they will only build me 4 pistons minimum. Great, $600 for 4 pistons. I can buy a whole set for the 400 block for real close to that price. That BB build is looking better all the time.

If you had the exact same clearances in this motor as the other 2 motors, and they were fine. I would look at what oil mods I did to the oiling system this time. See if you did or didn't do something right. But these guys know way more than I do otherwise.

Hughes suggested i may have bored thru a galley some where creating an internal leak, but what dont make sense to me is why i had 75# oil pressure for most of the run time.

Where was the gauge? You had pressure at the gauge sure, but somewhere between the pump and mains you had blockage imo.

Almost like the main bearing that feeds the crank had the hole in the bearing shell off of alignment with the hole in the block.

Are the bearings black from the coating or because they were not well lubed?

I am not a fan of drilling all the passages way bigger, it means longer on a cold start to fill em all up and with 40-80 PSI should give plenty of volume to the crank through the factory passages, maybe radius some of the sharp edges, a crank scraper, a couple extra oil holes in the filter plate, full groove mains if your gonna turn a lot of RPM and call it good, too many people way over think the oiling on a 6000 or 7000 RPM SB.

Like others have mentioned check for a passage bleeding internally, it may not have gone through at first then after running a little it popped through a thin spot.

Both I'd say on the bearings.

yep and the bearings were in the proper orientation with no oil hole blocked. just looked at the oil gallerys again and no blockage.

they were black with coating but that is gone and the black ones you now see are burnt.

calico rod bearing and fereral mogul main.

Looks like it went tight and killed it.... Just my 2 cents

I know you answered this and said it was checked but I am sure curious and I know its to late now BUT after the rod bolts were changed out for new ones were the rods resized and checked out again. .002 thousands it should have sailed through the dyno hits unless after changing the bolts the rods were just slightly out of round. It sure wouldn't take much.

That's why you use a HV pump. You can't get enough oil to these things. Open up the oil galleries, control all the internal leaks and get as much oil as fast as you can out of the pump and to the crank.

Yes, I screwed the new bolts in before I dropped them off for checking and resizing.

I'm at the point that I think a $4 oil filter killed a $10000 motor. My thinking is the filter was a street filter with tight pleats and could not pass non synthetic 15/50 thru it quick enough.

Could very well be, except the filter had a bypass valve in it, didn't it?

R.

That's true most do. I'm not sure about this one.

What brand and P/N

The pressure reading is picked up after the filter. If the filter restricted the flow, the pressure would have dropped.
Doug

I know you said it broke at 6k RPM. Maybe I missed it but what was the max RPM the engine had seen since being first started? It was likely hurt previous to the dyno run it broke on.

As DVW posted the pressure is read after the filter. Did you cut the filter open afterwards?

I don't remember Mike, but it is the short purolater white filter.

I don't have the print outs yet maybe tomorrow as the Dyno operator wants to see the broken parts. I believe 6500.

I guess that would rule out the filter. If the pressure was too high could it cause the oil to yet behind the bearings? Second thought is it possible to have pressure with low flow?

I've seen that happen but it was with a lot more pressure than you stated. Like 100 psi hot.

The guy spun the rods out of a half dozen 340s revving the wee out of them. Went back to more conventional oil pressure and never spun another one.

Kevin

Yes you can have pressure and not flow. Pressure is resistance to flow. This shows up in fuel systems where the line pressure is not enough to overcome G forces. So it will have pressure but not flow.

In this case if it had pressure at the gauge it had flow as far as the right lifter galley. It is possible to reduce flow down the feed holes to the mains but that would mean all 5 were restricted as all the bearings look suspect. Curious, did it have more than 50 psi on the previous runs?
Doug

If the pick-up tube wasn't tight enough it could of rotated down and been on the bottom of the pan. I guess I typed before I thought about it un-screwing, [in earlier reply]. That box on the end of the tube could cause it to rotate with all the vibration. I make a brace to support the pick-up tube.

I have seen the pick-up tube break off where it threads into the pump and fall off. I have also seen a piece fall off of the windage tray and block off the pick-up.

All of the bearings look starved for oil, so something cut off oil supply.

If oil could get behind the bearings, other than a minute amount of wicking, your bearing bores would be too large or out of shape. Not enough bearing crush. If the bearing are being crushed properly, there is no way the pump could force oil behind the bearings and reduce clearance between the crank.

Regarding the high pressure and low flow, it is possible to happen in certain systems. I am not familiar with small block Mopar oil passages though, and where the gauge port is relative to the pump and oil passages. That is a key thing.

Yes it had 75#. The pickup was horizontal to the pan and tac welded to the pump.

If your pressure gauge is one of the first things inline after the pump, it can show high pressure with very little flow. If there is a blockage and the oil can't flow enough volume beyond the blockage/restriction then it cause issues.

You cannot build pressure in a system unless there is enough flow to offset the leakage. Normally all balanced oiling systems can produce more volume than needed, the passages and relatively small bearing clearances produce restrictions and allow pressure to build. Restrictions are not bad if you can get enough flow through them, if the restriction is too much then it is bad. It's all about balance, carburetor jets and air bleeds are restrictions, if they aren't too big or too small they make things work.

Pressure pushes things, on engines pressure pushes fuel and oil to where it is needed. That is the function of pressure. Volume is important also, there has to be enough volume so there is a good film of oil between the bearing surfaces. Since it is an open system unlike a tire without holes, the pump has to be capable of supplying enough volume to match what leaks out.

One thing most people do or have done that relates to hydraulic (oil pressure and volume) is use garden hoses. Attach a hose to a waterline (faucet). Put a shut off valve on the end, and then attach another hose. If you turn on the water it will begin flowing through the first valve and first hose, then through the second valve and into the second hose. Now start closing the second valve that is in between the two hoses, and the pressure in the first hose will get higher, and flow into and out of the second hose will drop. You may notice the first hose swell as the pressure builds. A restriction has been created with the valve. If you turn it all the way off flow will completely cease, but there will still be pressure in the first hose.

Anyone that has worked with water systems that branch out to several outlets (watering the lawn, house plumbing, etc.) understands that you need to have enough volume and pressure going into the system to service all of the outlets. If one branch is too large, it starves other branches and if you add a restriction on that branch it will force the flow to the other branches.

An oiling system is essentially a series of passages or galleries (hoses). Restrictions (analogous to un-adjustable valves) in the system could be the size of the passage, and the bearings and lifters are control flow according to the clearances.

Your problem could stem from an oil delivery problem, it could be a clearance problem, it could be your rods weren’t as good as you thought.
There was obviously a problem, or perhaps more than one. The thing is, if it was a problem with the rod, bearing, or crank pin it has been destroyed and you may never know for sure if that was the problem or not, unless you find another smoking gun. What you may need to do is check everything that is left and all new parts very well, reassemble, and go from there.

I don’t know who checked your parts before. They may have been dead on, or they may have been wrong but I will say measuring parts accurately and in a 3 dimensional fashion is not as easy as it might seem and experience and technique are very important.

If a pump is sucking air through the pickup it will still move oil and build pressure, but foamy oil doesn’t work too well. Something to keep in mind. One more thing, was the oiling system primed before the first start up?

How do the cam bearings look?

I am far from an expert.
That said, the first thing I would blame would be the oiling mods to the block you did.
I have never fooled with the factory oil delivery, and never had issues on 340, Or x block, running 7500 lots and lots of times, for years and years.
Fiddling with factory engineered stuff scares me.
You didn't do those mods to your old block, no failures. You did to this build, failure. That would be my suspect, to much oil somewhere, not enough some where else. I believe in your attention to detail regards measuring and assembly, that's proven good. Your other stuff ran a long time. Looks to what you did different....... Oil mods

that has been in the back of my mind since the day it took a dump. no i have not looked in the filter yet. i figured its just full of scrap anyway.

So it dropped 20 psi? that would have bothered me.
Doug

I'd still cut it open and look. This thing was eating it's self up, as someone else mentioned, all the bearing damage didn't happen on the last pull.

my oil pressure has always dropped when the oil gets hot and this is with all my engines. 20psi is not that big of a drop from cold to hot in my experience. now when it went from 75 to 55 (i did not know that til after the last run) thats a different story. the last run did not go very high in rpm, i dont remember what rpm at the moment. watch the vid i posted it shows the rpm.

i will as soon as i can. ill cut it open and get a pic.

Sorry to see this carnage, good luck on new build



I have a question (I run big blocks so kind of a hijack) I saw someone mention a page or two back to run high volume oil pumps. I have been told not to run high volume oil pumps but to run high pressure oil pumps. Does anyone input on this? I ask here because it would in theory apply to both small and big blocks. I ordered a H/P oil pump for 451" build originally and wiped a cam lobe, lots of fine particles (not gritty oil, just shiny oil) so I ordered a new H/P pump, cam kit and other parts. Now I am rethinking H/P pump.

You want flow.. you dont need added pressure..
with the high flow pumps you get about 25% more
volume from it... flow vs restriction gives you
pressure... on a high pressure pump all thats
changed is the by-pass spring
EDIT
All the pumps I have tested have a by-pass pressure
of about 70#(thats the regular pressure pumps)

Been running hv pumps in everything I ever owned small and BB w/zero issues but have been using one of the best machine shops on the planet(Pettis)so that definitely helps w/all of the necessary clearances.............

Just back from the machine shop. Dyno operator took a look at my scrap metal and all he could say is bearings show heat. He installed #1 rod bearing in the #1 rod torqued bolts to 63 and mic'ed it. .0025 and didn't think bearing clearance was an issue as most runs were low rpm and the mains shoed heat as well. He cut open filter and nothing but bearing material. He think the crank may have heat cracks as well. Just about a total loss here.

I ran stock bottom end 340s 7800 RPM for years with no issues other than pulling the big end of the rod egg shaped a little bit. When I went to stock 360 iron cranks is when the problems started. The first was an iron 3.58 crank deal in a 340 block that spun a rod and blew up in 6 runs. The second was an iron 3.58 crank 360 block 7400 RPM deal that had to have 1 or 2 rod bearings replaced every 6 or 7 runs. Same rods everytime. You see copper in the System 1, you take the pan off and fix it. HV pump, good 10w30 oil, plenty of clearance, everything else looked fine. Tried oil pans, cross drilling and a bunch of other stuff which made zero difference. Ended up completely redoing the oil system in the block with all the tricks and even made up a few of my own. Would run all season and be fine after that and that's with thin oil and oil pressure numbers that would make most people pucker up.

Usually you see these problems with the 360s pick on one rod, maybe 2 once they try to spin it to 7k+. In your case, it sounds like all the bearings were hot and #8 burnt up first. The oil for 8 comes right off the oil filter, not the galley. It should be the last thing to run dry. That passage also oils the rear cam bearing. What's it look like?

Despite what the oil pressure gauge said, the problem almost has to be pump, thick oil through a tight filter, adapter, passages or something else in the rear of the block related, for the entire bottom end to look like it was starved for oil.

I see no wear on rear cam bearing.

Do you know if any of the rods were resized? I run a machine shop and I see many such jobs not correctly done, which means the surfaces ground are not even, and when resizing on a honing machine the big end and small ends ar not parallell anymore. You cannot check this simply by measuring; you need a rod fixture to show it, and then bend/twist the rod if it is twisted or bent. If a bent or twisted rod is not corrected it will make the bearing run on the edges, and that can take out the bearing when you load it. Check the other bearings to see if they have abnormal wear, and ask your machinist, or check your bill if it is specified.

I paid for it. Don't know if it was done.

The only knock I know of against high volume pumps is that if the engine is "tight" enough where it doesn't bleed off a lot of oil when it's running, sometimes the pressure relief valve can't flow enough oil to control the pressure.

Most of the stock type HV pumps cant flow enough
by-pass if the engine is tight.. it gives high
pressure even while its by-passing... I have
tried to open up the by-pass but for myself it
didnt matter because I run .003/.003 on all my
junk... but usually with a tight engine and thick
oil it wont by-pass enough... he started out with
a 100psi cold and as it warmed up it dropped to 75..
myself I would never want more than 70psi even cold

This discussion is getting up there to the pinion angle-8-3/4 level, wow, only on moparts. Kinda fun, yes?

Look for witness marks on the trustside of the rods. If the cap is not inline with the rod it will often show up in the witness marks between the rod and crank sides; uneven from side to side. Check the others that are not broken! Also look for uneven wear on the other rodbearings.

Whats wrong with trying to help the guy out..
he had a issue that he cant find at the moment

Nothing wrong with trying, but all we have are photos and what he's told us. WE can't inspect these parts up close like a good machinist can, there's a ton of things that needs measuring-inspection, so we're all just shooting in the dark. It's a wonder he's not confused with all the conflicting opinions of just the bearings, let alone the rest of the engine. A good engine builder-machinist is his only recourse to learn what happened. I wish him best of luck.

The crank never got oil, why?

A machinest/Dyno operator looked at everything and took some measures. Said the bearings show heat. Had pressure but no flow. I don't understand. I did find the rear main cap cracked in two places so the block is junk. I'm putting this behind me. Thanks for trying to help. I will never modified another engine block oiling system. Promise

Kick rocks goof

I seriously doubt that you mods killed it.

What a DICK.. a new ASSS hole

You swung for the fence and got bit, it happens. Don't hang your head down at all. You came on here and put your dilly on the table and it shows you have a pair. Also the cracked rear cap could've been the whole problem. Ok I'm gonna put this thread behind me now to.

I have never lost an engine in my life, including Chevy's. First time for everything. Moving on to big block world. Thank you for all your help guys.

Dave sorry your thread has gone in the ditch. I hope you find what caused your issues. Step back up to the plate and keep swinging, you'll hit out of the park.

Yeah I understand. There's been enough suggestions said here. Its all good.

That whole deal is a bummer, as I am right behind you. I should be on the dyno soon.

Can't say I blame you for just moving on.

Good luck to you. Im sure everything will go fine. My deal was just a fluke.

Anyone looking for any small block performance parts i will have some in the for sale section in the coming weeks. Just have to get things cleaned up first. indy 360-1 fully ported,indy intake ported,sheet metal valve covers with BLP spray bars,hedman race headers etc. I think this issue will go down as wrong oil filter and wrong oil for now.

Sounds like a good reason to shut this part of the board down

Or only allow ... Guess my HP threads ....

Though I hate to see anyone blow anything up, the forensics are interesting to me. Let's face it not many of us build engines by the dozens. Every thing learned will make us all better engine builders.
Doug

I had one of the short white purolator filters fail on me also. My oil pressure gauge got very sluggish. I was just a few miles from home so I came home and swapped the filter and it fixed it.

I have heard purolator makes the mopar filters, I have used lots of those with no trouble but the one purolator cheapo I ran failed.

Sorry I could not find the cause of the carnage for sure,so we could all learn from it. I will post if I do.

You had run this crank, this block, these rods, at these clearances, with thicker oil and likely same type filter in the past with no issues. So WHAT changed. You heavily modded the oil passages, but you did a lot of what is standard procedure on many small block builds, so that shouldn't be an issue, unless it is broken through somewhere you aren't seeing. Now you say the rear cap is broken. That could have happened first, or as a result. If it broke first, would be a problem and usually a broken crank does that. Crank MAY be broke, will have to Mag it to see, IF you even care. If crank is broken, my GUESS would be the root of the problems...........but sometimes shizzit just happens and you never really know what happened first. If you are confident the machine work was right, your mods were sound, the clearances were right, it was assembled correctly and it just broke. Accept it for what it is, a bad break and move on. Don't let it make you question what you did or how you did it. We all want to say "this did it".......well sometimes you just don't know. So don't pin it on oil, filter, or anything else, unless you KNOW. If you have built several and then you break one, doesn't mean you don't know what you are doing or even did something wrong. Just keep on keeping on and file it as "bad break". It's happened to about everybody

Agree with all of this except the last sentence. If you build engines for a living, or even do it as a hobby and say you never broke an engine, you either are lying about how many you built or how many you broke.

EVERYBODY has broken an engine along the way. Or poked a hole in a head while porting. Everybody.

Isn't that what I said?.........I said "about", because if you have only built a couple motors in your lifetime, you may have never ventilated one.

I took the thrust bearing out of a brand new 408 with a real stupid move that I should have caught. To save some time and labor I left the transmission in place and mated the engine to it. I didn't catch a tight fit on my convertor hub in the crank. K1 and Eagle cranks both had an issue years ago with not enough clearance. On start-up it pushed against the thrust taking it and blued two rods and took out the bearing from the trash in the oil. I lucked out with it only needing totally torn down, cleaned, cut the crank, new bearings, honed again, new rings, two rods, and two Diamond shelf pistons. I was about sick in my stomach over that one.

I believe most of us have had a issue at one time
or another.. but it seems on this board that everyone
is perfect and NEVER had ANY issues with ANYTHING..
as Dave has posted I did too with my issues.. only to
get CRAP from a few.. looks like we should never post
about things that dont work out right... and of course
they probably NEVER built ANYTHING THEIR SELF but will
[censored] about others

My point was that I wish I could have found the cause, then we all could have learn something from it. We didnt learn what not to do to cause an issue like this. Modding oil system,single groove main bearings,stud girdle and heavy oil on breakin was the only thing way different than the other builds.

. If you post be prepared for all the replies, good and bad.

I certainly wouldn't decide to not work on an oil system again. I know how much difference it made in my situation. Just need to decide what's appropriate for your combination of parts and RPM range.

After blowing one up, I became a believer in the System 1. If there's an oil problem like that, it will show up in the oil filter before it becomes catastrophic. I about wore the threads out on that trash can checking the filter on motor #2. At least until I felt like I'd gotten a handle on it.

Oh I know.. we have all these righteous people
on here that have NEVER had a issue.. I know
I wont say diddly from now on if I have a issue

This is moparts....lol

Don't beat yourself up, but it would be good to find the cause if possible. As Monte said, sometimes it is impossible to know for certain.

If I had to bet, after reading through all this, something in your oil system was amiss. If it were my engine I would carefully inspect all of the oil passages for places that were broke through, missing plugs, etc.

Given the nature of cast iron it's not inconceivable a thin section of drilled out passage could break out just from oil pressure.

Maybe we should all confess to screwing an engine up...

When I was 16 someone gave me a 66 dart on the condition I could break in the trunk and get his stuff out(he lost his keys), I pulled the back seat out and handed him his stuff and he handed me a title... the 273 had a nasty knock, tore the engine down had a spun rod bearing, new bearings were still loose so I stuck a flat hose clamp behind the top rod bearing and put it together, the supprising thing looking back is that it lasted 2000 miles includeing a trip from abilene tx to nashville tn, after I moved there it started knocking and it blew about 5000 RPM in 2nd gear one day and split the block in half up all 5 mains to the cam tunnel as well as various other obliterated parts.

Next engine I put together was a slant six for my moms full size van, I had a heart atack when I started it and it was knocking real loud, turned out I had not checked clearance to the oil pick up.

My first stroker was a 318 I had bored to 4.00 after sonic testing, split 3 cylinders in the forst 10 miles, found some real big places (pretty much all of it) with about 1/2 the thickness the machine shop told me it was. They refused to do ANYTHING to help me.

Probably the dumbest thing I ever did was put a rod cap on backwards during a between rounds piston swap thrash. It made it to 1000ft........LOL!!!

Very VERY off topic but just to show how fast things can go wrong. My Uncle a mechanic by trade for all his life was doing a brake job (front disks) for my Dad on his motorhome at Dads house. My Dad was sitting there keeping him company and my Uncle dropped the back pad while sliding the caliper into position. He picked it up and put it back in the caliper and finished the job. We left for Ocean City the next evening and we would stop for the night at Breezewood. It was mostly all turnpike and while were eating my Dad said his brakes were noisy. I climbed under the motorhome to take a peak and couldn't believe what I saw. The brake pad was installed with the metal side towards the rotor. I didn't have the proper tools to do the job so a shop at the bottom of the hill flipped it around to get us going. Had to buy new rotors and new pads when we got back home from vacation. You now what they say, poop happens.

LOL! Now that's some funny sh!t. Yes, we all make mistakes as humans do.

hate to hear about your broke engine.
I think the rods may have been fatigues if you had used them for 8 years prior to this build. I used to race Hemi's in Super stock and never had an issue for the first 3 + years running 3 nights each week and turning it 8000+ every trip down the track. Then we broke a rod in my good motor and went to the back up and it later broke a rod too. I had rebuilt the rods every winter in both motors with new bolts on a regular basis, but metal does fatigue after a while of continuous cycling.
Good luck with the new build.
Jerry

Uhh hi my names Chad and I've broke some stuff, the 451 in my Demon has been down twice since its build, first time not sure why it bent a rod but it did it was tight from get go. New builder and much free'er second time around had ran great then it wiped a cam lobe. It is down now being fixed. The cam lobe happened 5 years ago, someone told me it was likely an issue with removal of zinc. Was it but it's getting fixed finally. Hope it doesn't happen again.

the older i get, it becomes apparent the dumber i am. so much to learn and the clock is ticking while the sand runs out.........

I feel your pain buddy.

X2