Engine guys, what went wrong? FT cam related *UPDATE*

Friend of mine installed a new name brand hydraulic cam and lifter set in his SB. Here are two lifters. One was obviously not rotating but one was. The others look good. This guy is no dunce and knows how to install and break in a FT cam. I have my idea of what went wrong but I could be out in left field. So before he wastes his time and money to send this back to the manufacturer just to have them tell him to pound sand I would like some second opinions. This is not the first cam to be installed in this engine either. There was no problems with the original cam or the second cam, he just wanted something bigger.
So before you ask, he used the supplied cam lube and even bought and used extra. He added Lucas ZDDP break in additive as well as 5W30 semi syn oil.
Forgot to say, this happened during the break in cycle, no miles were put on this cam.

Not trying to a smartazz, were single springs used? Were the lifters checked for spin when turning engine by hand? Maybe cam wasn't ground properly?

He did use single springs for the break in. He claims when he first assembled it with the intake off none of the lifters were spinning. So he backed off the rockers some and turned it over with the starter. Still only a few were spinning. He torqued the rocker shaft back down and spun it over, no spark plugs, until all the lifters were turning. He said some turned faster than others but all were turning. He then took the rocker shafts back off, popped the lifters up and relubed the face. Reassembled everything and fired it up. He said it fired right up, ran it up to 2200 and checked the timing, it was retarded 6 degrees at 3000. He set the timing and let it run for 30 minutes varying the RPM for the duration but never went below 2000.

Your first post says "This guy is no dunce "

Your last post sorta says differently. Ive noticed alot of cam companies include the "hey stupid" sheet about the whole lifter rotation gig as its basic stuff that if ignored will get this.

OR he got some bad parts.

I may get flamed, but any hydraulic or mechanical flat tappet cam that has spring specs from the manufacturer for more than 120 lbs on the seat, I will not install.
Have done the weak break-in springs, run at higher RPM to break-in, etc. etc. My way of thinking is that the seat pressure has more effect than the open pressure on killing a cam, because the lifter must fight the seat pressure to start rotation of the lifter. If the lifter does not rotate the cam will not last, no matter how good the cam and lifters are. If the lifter is tight in the bore, or loose in the bore both are just as bad on a possible failure.

I have used Lifters with an EDM hole, and grooved lifter bores with some good success to increase oiling to the lifter. Unless the guy just needs a big flat tappet cam, for class rules etc. My advice is if the cam needs more than 120lbs on the seat, just buy a roller with similar lift and duration. A new engine full of metal is not worth the money you save on a flat tappet camshaft.

Clearance of the lifter bores, how straight the lifter bores are machined, having some issues that makes you start and stop the break-in process, are just a few of the things that will kill the cam. Your post did not mention the spring pressures, ALWAYS double check the spring pressure, never trust a head manufacturer on what the spring pressure is on a head, especially if they are some of the cheaper imported ones.

Nine second Phil had a 1969 340 block that had one lifter bore,#5 o r#7 intake, that wasn't machined properly from day one, it would eat that lobe after around 15,000 to 22,000 street miles
On your friends block I would remove the timing gear and rotate the cam and lifter by hand or maybe with a big drill motor to make sure the lifters are all rotating well
If they don't spin well have the block lifter bores bushed or go with a roller cam and lifters

hi

lucas ,5w30 semi synthetic ,supplied cam lube ?


no cam manufacture i know of recomends synthetic oil for brake in .


compare the cost of the products used and the failure hassel to 6 quarts of amsoil 30 weight brake in oil .


never a failure and run it for first 1000 miles before change in all engines i build .

Its any mutable things that could have caused this. Not being there its up to guess work. I have seen some simple but stupid stuff. No lube on the push rod tips (both ends) is one.

But in the 40 or so cams I've installed over the years not one failure. I'd say 80% have been retrofitting a new cam in a well used engine.

But.....

I never run big springs on break in. The lightest spring that will not coil bind.

Oil only on the lifter bores. I have used just a little assembly lube mixed 50/50 with 5W30. Oil is oil on lifters so synthetic is OK if the rings are seated. On the cam lobes I will brush on some assembly lube.

I use a lifter extractor to clamp on to each lifter as I install them and with just oil in the bore, I hand spin it while pushing down to feel for any binding.

I've put flat washers curved to fit under the rocker shafts to lessen the preload on Hyd FT lifters. Loose lash Mech FT's

But with todays cam designs, I do not think I will not ever run a FT cam again. Rollers are getting cheaper and offer up so many plus'es over a FT.

He used the stock springs for break in.

Ok so how is he stupid if all the lifters were rotating?

This is not a new build. The engine has had two different cams in it already without a problem so I can't see how this would be a block problem.

No he used the Lucas additive, not their oil. I fail to see how using a semi-syn oil with the ZDDP additive could have caused this. Since 14 of the lifters are fine I don't see how the oil was the problem.

It’s not an oil issue. The one thing that stood out to me was cranking it over without it firing. If it’s not ready to fire, I don’t ever crank on it with the starter. I’d have to go back and read your OP but it seems to me it sounds like he cranked on it quite a bit before he actually fired it. It doesn’t take much to do the initial damage that doesn’t show up right away.

FWIW I never ever use less rocker ratio, or pull inners or any of that. Ever. If the lobe is that aggressive it needs a roller on it. My last cam was close to Comp’s MM lobes with 155 on the seat and 355 open.

So my guess is he hurt it cranking on it.

You may be right and that was my suspicion as well and that is why he popped the lifters back out and added more lube before reassembling. It's not a big cam, .480 lift, 239/246. What I don't get is why weren't the lifters turning initially? I mean is it really any different turning it over with the starter than by hand? He said the battery was down and the starter has been dragging anyway so it wasn't spinning over real fast. How long would it have been before the lifters starting turning if he had just fired it?

Here is my take, long long ago cams were different and many times on a cam swap if the old lifter slid out easy and the new one slid in easy I never had a problem.

Then everyone started mashing cams and getting nervous, so I started to set each lifter for each hole and it had to slide through on its own (many times a snug one will free up just by manually by hand with some lube cycling it up and down cleans things up) and then that lifter is good for that hole), then with the cam in and the weight of the pushrod spinning the cam gear by hand to verify all 16 move, it seems it takes little to get one hung up and not spinning.

I live in a good spot and hardly never shop break in a cam, its always a half hour of mild rpm, mild fun driving, just keep over 2k and let it vary.

But anyway,to me it kinda sounds like things were not happening in the rotation dept and like most posted, a fresh motor does best if it fires in the first three/five revolutions and its not hard to do although freaky to have a fresh motor fire so quick.

One thing to note is both your lifters look like many 340-s, even 318-s that ate cams, some of them were even worse and the lifter was very hard to remove.

Sucks though, hate to see it.

How much preload on those lifters, Stock springs coil bind around .480 lift. Lifters pump up , go into coil bind ,wipe lobe. I would check very carefully for mech interference on those particular ones from lifter to valve seal.

Thats a good point, AND for a .480 lift FT cam, why 2 springs in the mix? Or didnt he get that far? Isnt that single spring territory?

Sometimes people get lucky........ where there is no lifter rotation...... and it doesn’t eat the cam.

Then....... other times there is plenty of rotation...... and it still eats itself up.

In these two cases...... the one without rotation only had about 1/2 a thou of lobe taper on the cam.
That’s usually a recipe for a wiped cam.

The one that ate the lobe had the full 2 thou of lobe taper.
It was a fast rate .904 design lobe, but was run without high zinc oil(Castrol GTX).
3 other lobes were starting to go.
It was an unbushed block, so there’s a possibility of lifter bore position being a contributing factor.

Both of these motors rec’d different cams that worked out fine(so far...... 1 year of service)....... so it wasn’t like the block was screwed up enough so that nothing would work.

I always use clean engine oil on the lifters and bores before I assemble anything and if the fall down the bore on their own, just by their weight, the bores are good to go.

I’m starting to think the slow turners may have been poorly finished lifters (found that in about 2006 or so...the lifters didn’t have enough radius on them or non at all so I put them in the lathe and verify .0025 or a bit more crown on them or they go back) or the cam lobe didn’t have enough taper on it to spin the lifters at all, or not enough.

I still use FT stuff on my street junk because I’m not a fan of hydraulic rollers but I check and verify everything, including lobe taper and if doesn’t pass muster it goes back. It’s too expensive to have to do it a second time.

So what do you think? Should he send it back and try to get another one?

If he doesn't send it in they can't replace it, can they I'm not saying they will replace it but if he doesn't try they won't

Well my question is if you all think it's worth the time, hassle and money to send it back or are they just going to tell him to pound sand anyway? I know you all don't know just looking for opinions.

I’d send it back. A builder local to me lost 2 Comp cams in a row. Comp replaces both cams and lifters, even though they have no idea what went wrong. So I think it’s worth the hassle at this point.

This is sort of testing the waters, and it only works if you caught the company during a management push for customer satisfaction.

Call whoever it is up and see if you can get a Tech guy to agree to at least inspect it and give his opinion on what happened.

Once the part is in their hands, it becomes "chicken or the egg" and they may agree to replace it for goodwill
based on the part potentially being at fault.

If you aren't lucky and their budget is pulled or frozen, they will just tell you to not waste your time sending it.

If they won't agree to an inspection, ain't no way they will agree to a replacement.



Comp is generally not too bad to deal with.

Well I didn't say whose cam it was but it is a Comp cam. They have given him a return authorization number and said a replacement would be dependent on their inspection. Shipping of course is on him. So thanks guys, I appreciate it.

This scenario is nothing new. Flat tappet cams are a risk nowadays across all brands because the quality left the building years maybe decades ago. Unfortunately a conversion to roller is the only sure way to avoid this but mopars are $$$$$$$$$$$$$$ to convert. I see for my future project Im looking at $1300 for roller cam lifters push rods adj rocker arms springs etc. I remember on this board around the year 2000 when the high failure rate of FT cams would come up. Someone pointed out the reduced zinc and sulfur of our beloved oils. A short time later a member posted his new lifters and the LACK of a crown on the bottom. Then as years rolled on we learned about metal hardness (lack of) being an issue. I miss the days of low risk low cost high performance flat tappet cam kits.

Somewhere in a box here I have the original 66 273 D Dart cam and lifters. Last time I seen them was 20 years ago but when you put that lifter on a hard flat surface you can rock it some due to the crown. The cam you can see the taper to the lobes when you run a dial indicator across its face.

After 40-50 years lifter bores get worn and how many really check them?

15-20 years ago we used to do quite a few of some 350sbc oval track motors.
There were two classes, and we did several for each class.

The milder class were 8.5cr, ex manifolds, stock 2bbl intake, and heads with 1.72 intake valves.
We had done a pile of cam testing on those things, and had it narrowed down to 2 different ones.
One was a Comp, the other was a white box special.
The Comp was about 5hp better, but cost twice as much.
If it was for a customer that wanted the “good stuff” and was okay with paying for it....... it got the Comp.
I wasn’t doing assemblies, but checking for lifter rotation wasn’t part of the normal assy...... and cam failures were very very rare.
So, I’ve got one of them on the dyno and fairly quickly into the cam break in I start hearing some clatter.
We ran these with zero preload, so if there was any clearance in the valvetrain, you’d hear it.

Pull the covers, find one rocker is just barely loose.
I reset it, start it back up....... a few minutes later, the clatter starts to come back.
Pull the cover...... it’s the same one loose again.
Okay....... didn’t make it through break in.

Pull motor off the dyno, put another one on.... and carry on.

They pull the cam out........ one lobe and lifter are starting to go away.
The others are perfect.

Stick another cam in the motor, new lifter in that hole, install pushrod and rocker...... turn the cam round and round...... no rotation.
Decent rotation in any other hole.

Okay, it’s a lifter bore problem.

Checked lobe taper on cam, it’s basically right at .002.
I order a cam and have them add a thou of taper..... so, .003.

Get new cam, check taper....... it’s .003.
Checking for rotation in the offending bore.......lifter starts to move...... barely....... then goes back the other way.
The lifter still won’t go round and round.
The others all really whip around good now with .003 taper.

What to do, what to do? Really don’t want to pull it all apart and get the lifter bores done.
Well, at that point in time it was easy to get Schubek lifters..... especially for a Chevy.
We bought one lifter and put it in that hole.

Buttoned it up and it was good to go.
Worked like a champ.

So Comp Cams contacted my buddy and asked him what his break in procedure was. He told them everything I told you guys and they said they would send him another cam but asked that he use a dedicated break in oil. So we will see how it goes.

Use Driven “BR”, with no other additives.