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440 dead miss 2 cylinders??
Posted By: MMiller
440 dead miss 2 cylinders?? - 09/11/11 02:23 PM
Compression tests have reveiled #1 and #5 have no compression with valve train on. Measure the compressed height of the valve springs and they are 1.63". Take off the valve train and the valve springs measure 1.93". Put compressed air to the cylinders, with no valve train on and they hold great. With rockers on, and compressed air, it either leaks out the exhaust or the carb.
Engine back ground: Its a 440 with a mild .470" lift cam, hydraulic lifters, stock valve train. It ran fine at the end of 2009, and was parked until about July of this year. The 915s were put on in 2009 and only have probably 25 miles on them, as its a pulling truck, trailered everywhere, not streetable. Heads have new valves and 3 angle valve job.
I pulled the lifters on #1 and disassembled them. They looked great, as far as wear, and found no contamination. I put them back in and the problem is the same. This engine ran great in 2009. The shortblock has been together since 2003 and is solid. Compression checks in other cylinders show 215 psi cranking pressure.
What am I missing? I am going out later today to take off the rockers again, and check the height of the valve stems, but I think they are consistant. I did put new valve springs this week, because I think it was floating the valves after sitting all this time. I also ran a bunch of Sea Foam in it last night for 45 minutes at 1500-2500 rpms, and when I shut if off, it was still missing. Ignition is checking out fine.
Thanks for the help guys.
Michael
Posted By: RapidRobert
Re: 440 dead miss 2 cylinders?? - 09/11/11 03:12 PM
w valve train off leakdown is good which tells you the long block (incl the valves in Q) are sealing. Setting #1/#5 cyls on TDC compression one at a time of course can you see what is holding the valves open? how much preload/can you move the p rod(s) down further by hand. From your descrip it almost sounds like the cup/plunger etc in those 2 lifters are hanging up even tho on dissassembly they looked OK
Posted By: mikemee1331
Re: 440 dead miss 2 cylinders?? - 09/11/11 03:22 PM
Quote:
w valve train off leakdown is good which tells you the long block (incl the valves in Q) are sealing. Setting #1/#5 cyls on TDC compression one at a time of course can you see what is holding the valves open? how much preload/can you move the p rod(s) down further by hand. From your descrip it almost sounds like the cup/plunger etc in those 2 lifters are hanging up even tho on dissassembly they looked OK
i would disassemble those 2 cyl. and make sure everything is straight and the keepers are on correctly.
Posted By: Strawdawg
Re: 440 dead miss 2 cylinders?? - 09/11/11 03:24 PM
X2....if air leaks out with the valve train on...then the valves have to be open....valves are not stuck open because it seals with the shafts removed. You should be able to see this in the preload and/or with your eyes (watch the springs for movement as well as the lifter) as you tighten the shafts down while those cylinders are at tdc.
While you are at it, check the the preload on a couple of other cylinders to make sure it is not borderline excessive for the heck of it.
Posted By: MMiller
Re: 440 dead miss 2 cylinders?? - 09/11/11 03:53 PM
So with the engine off, I should be able to collapse the lifters? I'm not sure that I can...When I pulled the lifters for #1, I could not push them down until I disassembled them. Without oil in them I could push the plunger down.
I think that when I work on it today, I will move the lifters from #1 to #3 to make sure my problem moves to #3. If it does then I will know without a doubt that the lifters are causing me grief.
If I can get the lifters to work correctly, then I would put them back in thier proper holes, otherwise I guess I'll have to get new lifters.
Thanks guys, I thought I was going crazy.
Michael
Posted By: Strawdawg
Re: 440 dead miss 2 cylinders?? - 09/11/11 04:16 PM
If you do that, you will probably wipe the cam...once broken in, the lifters MUST stay with the original lobes!!!!!!!!!
yes, the plunger should move down so you have a problem...get a couple of new lifters and do a fresh break in sequence just like you had changed cam and lifters....
Posted By: RapidRobert
Re: 440 dead miss 2 cylinders?? - 09/11/11 04:25 PM
Quote:
I will move the lifters from #1 to #3 to make sure my problem moves to #3.
You're not going 2 start it w em switched just (re)checking leakdown?
Posted By: Challenger 1
Re: 440 dead miss 2 cylinders?? - 09/11/11 04:26 PM
Don't move lifters around.
If everything else checks out like everyone has said, then I would put shorter push rods in those 2 clys. The others ones may not be far behind.
New valve jobs sink the valve deeper in the head which gives you taller valve stems and if the valve stem isn't ground, then you need shorter push rods with non adjustable rockers. For performance you really should upgrade to adj rockers even with a hydralic cam and then you wouldn't be having this problem. imo
And I seriously doubt your gonna find all the valve tips at the same height, after a valve job. Your machinist didn't/couldn't charge you to "blueprint" em.
Hope you didn't run it too long if the valves are actually hanging open.
That's why adjustable rockers are handy for this kind of thing.
Posted By: RapidRobert
Re: 440 dead miss 2 cylinders?? - 09/11/11 04:47 PM
In the back of my mind I thought it was unlikely that 2 lifters could b hanging up esp as they tend 2 b trouble free & when they do act up they just get noisy & w the subsequent posts it sure sounds like a preload prob. Holler when you find something
Posted By: gtx6970
Re: 440 dead miss 2 cylinders?? - 09/11/11 04:49 PM
I'm in this very boat right now on my truck. After I got the transmission straighted out . Wife drives the truck one day. And all of a sudden I now have a dead miss in 2 cylinders.
Compression ck showed one cylinder on each side show 25psi or less
pulled the heads to find exhaust seats sunk into the head pretty bad in the affected cylinders
Worst part is - machine shop called friday morning, both heads are cracked. Not been a good last couple of weeks
Posted By: RapidRobert
Re: 440 dead miss 2 cylinders?? - 09/11/11 05:36 PM
Quote:
pulled the heads to find exhaust seats sunk into the head pretty bad in the affected cylinders
Worst part is - machine shop called friday morning, both heads are cracked. Not been a good last couple of weeks
Murphy's law is no fun 2 deal w. Sounds like you're in the market 4 a good set of heads w hardened seat(s)
Posted By: MoparforLife
Re: 440 dead miss 2 cylinders?? - 09/11/11 06:05 PM
Adjustable rockers???? If so did you adjust them properly. With the lifter on the base circle of the cam make sure that the lifter cup is at the top of the travel with the lifter, cam, push rod and rocker just making contact. Now adjust 1-2 turns more. Make sure not to adjust the 0 + off the plunger that is in the bottom of its travel.1.63 is pretty low installed height for a big block. Installed height for a big block is usually in the mid 1.83.1.86 range.
Posted By: MMiller
Re: 440 dead miss 2 cylinders?? - 09/11/11 06:26 PM
Not going to run it, I was just going to swap parts and see if the valves open....
Non adjustable rockers are on this motor. When I put it together years ago, it was a pump gas motor, in a truck that I drove on the street, 4 wheeled and street class truck pulled. It was an idle to 5500 engine. I put the small chamber heads on, switched to E85, and put a used twin disc clutch, and took the truck off the street. When its right it turns about 6000 rpm down the track with good power. I'm hoping to finish up a couple hooks yet this year, and next year building a fresh 470/iron head engine(rules on heads and cu.inch) and get some nice performance parts.
I'm not planning on doing anything to wipe the cam out, just making sure I spend money on the right parts. Been chasing this problem for a while. Don't want to spend more money then I have to on this bullet.
Michael
Posted By: Strawdawg
Re: 440 dead miss 2 cylinders?? - 09/11/11 07:36 PM
Good...it's hard to see experience thru the monitor
the plunger should sink into the lifter as you draw the shaft down until it reaches whatever preload your push rods provide. If it was fine before, then it is unlikely that you suddenly have to much preload now....sounds like something is preventing the lifter from adjusting as it should to the pushrod length
Posted By: mikemee1331
Re: 440 dead miss 2 cylinders?? - 09/11/11 08:25 PM
Quote:
Not going to run it, I was just going to swap parts and see if the valves open....
Non adjustable rockers are on this motor. When I put it together years ago, it was a pump gas motor, in a truck that I drove on the street, 4 wheeled and street class truck pulled. It was an idle to 5500 engine. I put the small chamber heads on, switched to E85, and put a used twin disc clutch, and took the truck off the street. When its right it turns about 6000 rpm down the track with good power. I'm hoping to finish up a couple hooks yet this year, and next year building a fresh 470/iron head engine(rules on heads and cu.inch) and get some nice performance parts.
I'm not planning on doing anything to wipe the cam out, just making sure I spend money on the right parts. Been chasing this problem for a while. Don't want to spend more money then I have to on this bullet.
Michael
it's funny - i'll bet most of us on this site (myself included) never considered a mopar in the way you use yours for!
Posted By: MMiller
Re: 440 dead miss 2 cylinders?? - 09/11/11 11:35 PM
it's funny - i'll bet most of us on this site (myself included) never considered a mopar in the way you use yours for!
Here's my favorite pic of the truck when it was still pump gas, and I wheeled it.
Posted By: MMiller
Re: 440 dead miss 2 cylinders?? - 09/11/11 11:38 PM
Posted By: MMiller
Re: 440 dead miss 2 cylinders?? - 09/11/11 11:44 PM
I did mess with it a little this afternoon. I pulled out three lifters and put them on the bench. I could not compress any of the lifters with a pushrod, and probably close to 125# of push. If I take them apart and get the oil out of them, then I can cycle them fine.
Unless someone can think of anything else to do, I'm going to order a new set of lifters from Comp tomorrow. I'll get some of those hydraulic lifters that are "anti-pump up" or something like that, to see if I can squeak any more revs out of this motor. I'm not scared of hurting the engine, the camshaft and stock port heads are probably my limiting factor in rpm range anyway.
Thanks guys, hope you enjoy the video and pics. Someday the truck is getting a nice body, painted in period correct, factory colors. Maybe a nice pale yellow with white top......or Macho colors. Haven't decided yet. I liked the show Simon and Simon...
Posted By: buildanother
Re: 440 dead miss 2 cylinders?? - 09/12/11 12:19 AM
You can't just push the oil out of oil filled lifters. The valve spring pressure itself needs a little time to bleed the lifters of oil on an engine when not running. Whenever I adjust the lifters on an adjustable lifter engine when lifters are oil filled, I find the pushrods will not turn easily by hand, so I continue to turn eng over and finish adjusting them all. If you then let it sit 5 minutes or so, the pushrods will then all spin by hand as long as cam is on base circle. Your situation sounds like too long of pushrods as somebody mentioned.
Posted By: Challenger 1
Re: 440 dead miss 2 cylinders?? - 09/12/11 12:30 AM
Go ahead and order lifters...
Posted By: MMiller
Re: 440 dead miss 2 cylinders?? - 09/12/11 01:01 AM
Ok, well after it set all night, I cannot spin the pushrods like you mention. I noticed that some I could, and some I couldn't. Of the ones on the base of the cam.
The lifters from #1 when I removed them, the plunger was pushed clear up to the snap ring. Plus they were holding the valves slightly open. I'm learing about hydraulic lifters, but I don't think they should be like that should they?
Thanks again for all the comments and info.
Michael
Posted By: MMiller
Re: 440 dead miss 2 cylinders?? - 09/12/11 01:07 AM
Quote:
Go ahead and order lifters...
I don't know how to read this. Do you feel like I'm wasting money buying lifters, or do you think I messed with it too much and really need lifters? I'm tired of chasing my tail.
Michael
Posted By: Challenger 1
Re: 440 dead miss 2 cylinders?? - 09/12/11 02:09 AM
Quote:
Quote:
Go ahead and order lifters...
I don't know how to read this. Do you feel like I'm wasting money buying lifters, or do you think I messed with it too much and really need lifters? I'm tired of chasing my tail.
Michael
You need shorter pushrods on some valves, plain and simple. If you don't have adjustable rockers to compensate for variances valve to valve.
There ain't anything wrong with your lifters.
Hopefully you didn't hurt a lifter or cam lobe by running it with not enough lash. They all should be checked. Easiest way is with the intake off. Set em once and forget about them for life of the motor with a hydralic cam with adjustable rockers.
You need to take a adjustable pushrod and see what length you need and compare that with the pushrods you're running now. I bet there too long.
Posted By: MMiller
Re: 440 dead miss 2 cylinders?? - 09/12/11 02:32 AM
Alright, I see what you are saying. If the plunger in the lifter is up at the top pushing on the snap ring, would that still indicate too long of push rod? Thats what is confusing me, I can see if they were way down in the stroke of the plunger. But these are up against the snap ring. I thought that they lifter was supposed to run partially down in the plunger stroke. That way they could compensate for wear. Is this wrong?
I'm sorry I'm being difficult. I've worked on diesels my whole adult life, and they sure a heck don't have hydraulic lifters or carburators.
Posted By: MoparforLife
Re: 440 dead miss 2 cylinders?? - 09/12/11 02:57 AM
Quote:
Alright, I see what you are saying. If the plunger in the lifter is up at the top pushing on the snap ring, would that still indicate too long of push rod? Thats what is confusing me, I can see if they were way down in the stroke of the plunger. But these are up against the snap ring. I thought that they lifter was supposed to run partially down in the plunger stroke. That way they could compensate for wear. Is this wrong?
I'm sorry I'm being difficult. I've worked on diesels my whole adult life, and they sure a heck don't have hydraulic lifters or carburators.
If the lifter is at the top of the travel against the snap ring the push rod is too short. You have to preload the hydraulic lifters somewhat. Some times the push rods are too long they push the plunger so far down in the bore that they bottom out the plunger then the person adds the 1 to 2 turns of preload and they are holding the valve open. This would be like preloading a solid lifter.
Posted By: MMiller
Re: 440 dead miss 2 cylinders?? - 09/12/11 03:07 AM
Ok, so if the lifter plunger is against the snap ring, the push rod is tight, and the valve is slightly open, and the lifter is on the base of the cam, what do I look at next?
Posted By: Strawdawg
Re: 440 dead miss 2 cylinders?? - 09/12/11 04:32 AM
new lifters(s)