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Thrust Failure affects lifters.


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I have about 500 miles on my rebuild of my 454. Last weekend, some of the rockers started rattling. I pulled the valve covers and at least 4 rockers were loose and the rocker nuts hadn't backed off.

 

I pulled the intake today and found 4 of the hydraulic roller lifters have collapsed. mad Some of the push rods have damaged upper ends, also.

 

My temporary exhaust exits out the sides, in front of the rear tires, so I probably drove 10-15 miles after the lifters collapsed, before I pulled in my driveaway and heard the rockers rattling.

 

The lifter part # is 854-16. Does anyone know of others that have had trouble with these?

 

Who makes a good roller lifter for a street engine?

 

Dan

 

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Thanks for the replies. I ordered the cam kit thru a local performance engine shop and they assembled the heads, so I don't know what the spring pressures are. That's the first thing I asked about when I called them last week and the shop foreman didn't know off the top of his head, but he said they wouldn't be very high for this cam and engine. (They build alot of circle track engines and some for drag racing.)

 

I emailed him a pic today and he called Comp. They said they'll replace them, as long as there's no foreign material in them to cause them to mess up. With 25% of them already failed I don't want them to replace them. They'll just send more just like them. crazy

 

Dan

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Yesterday, the shop foreman told me to check inside the lifters. I checked 3 of the problem lifters last night and I found some tiny "flakes" of metal in one of them. When I pushed down on each of them, all of the plungers came back to the top, after a few tries, except the one with the metal. I had to flush it out.

 

Some of the top ends of the pushrods are worn down, so I don't know if the metal just came from there or there's another source further down. I have great oil pressure and I didn't hear any noises down low in the motor that would indicate a bearing problem. I checked all of the rod bearing clearances when I put it together and had .0015" on each. The engine shop installed the crank in the block, so I don't know what clearance the mains had.

 

The metal in the lifters caused the plunger to not return to the top of its' travel, but I don't know why the plunger would have been so far down in its' travel in the first place.

 

I put a dial indicator on top of the rocker roller at #3 intake valve and measured .044" of vertical travel just by lifting up on the tip of the rocker arm, before I did anything else at all on that valve. When I lashed the valves originally, I used one full turn tighter after zero lash, as directed by Comp for these lifters. What caused the plunger to go so deep that it was able to get hung up there in its' bore?

 

I drained the oil into a clean, plastic bucket and didn't find anything alarming, but now I need to cut apart the filter. I'll need to tear the engine completely apart again and check everything, but right now, I think the lifters collapsed and then the pushrods wore down, causing the metal in the oil. crazy

 

I may be pointing my finger at the lifters too soon, but that's where I'm at right now. What do you guys think?

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I used 10w-30 for the break in and then went to 10W-40.

 

The shop did the machine work on all of the journals and supplied the "correct" bearings. I ground the ring gaps and installed the pistons. I went from memory when I checked the rod bearing clearances with Plastigage. I thought .0015 to .002 was good, but my memory failed me. My bad there. I should have called them or checked somewhere for the correct clearance.

 

They only polished the rod journals, but they undercut the mains .020" from stock. Now I'm wondering what clearance they used for the mains.

 

Thanks for the help. I started the engine removal this evening. frown

 

Dan

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Morel makes many of the lifters for Comp, Lunati, Crane, etc. from what I understand--both upper end and middle of the road. When you talk to Dave, I would recommend going with the Morel Sportsmans, not their street lifters. They unfortunately run around $600 though and they are known to be a little noisy but they are the best for any sort of performance use.

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I pulled the motor this morning and I think the problem with the lifters is caused by the rear surface of the thrust bearing being badly worn. mad The bearing surfaces are all showing signs of scoring because of the metal floating around in the oil from the thrust ring of the crank, but the rod bearings don't really look any worse than the mains.

 

The previous thrust/main bearing had some wear when I took the crank out during the rebuild and I had the engine shop check it. Later, I had the shop install the crank in the block and I questioned them about the thrust ring wear. The shop owner said it was not a problem and the end play was within specs. He said I should just make sure the torque converter was able to move forward at least an 1/8" from fully seated when I bolted it up to the flexplate. I was able to move it forward about 1/4", so it wasn't putting any pressure on the crank, at least while the motor was not running. It's the original converter and it doesn't look damaged.

 

I'm researching possible transmission causes now. I rebuilt the TH400 several years ago and now I'm wondering if the B&M rebuild kit or shift kit can be the cause of all of my engine problems. I just rebuilt this motor this past spring because some of the flat tappet cam lobes went flat. Looks like I need to check some fluid pressures. Any ideas? Any help will be greatly appreciated. smile

 

Dan

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My personal experience...I wouldn't use anything Comp Cams on my lawn mower....just saying..... I had one of their flat tapped lifters literally break into pieces on a 1500 mile, fresh (professionally built)engine.

 

Their reply was that they were not responsible for anything but the cam and lifters...not even the hole the flying bits of lifter put through my oil pan....

 

My 2 cents,

Steve

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I just had to do a complete refresh on my 496 due to a failed Comp Endura-X mechanical solid lifter. Not good at all, these lifters probably had less then 500 miles on them. Needless to say I didn't put Comp Cams back in it, and got rid of the Comp Cam itself. Went with the new Isky Red Zone EZ Roll EZX lifter. It's a bushed lifter so no needle bearings to fail. Crower has a bushed lifter out also. Supposedly this is the hot ticket to run if running a solid roller.

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Thanks to each of you that have replied. I appreciate you taking the time.

 

The subject title of this post is not accurate. Like I posted, after pulling the engine and checking the bearings, I've found the thrust bearing is worn badly and I believe it's caused by the transmission fluid pressure. It must be too high. The destruction of the thrust bearing caused the failure of the lifters. I'm finding with internet searches that this isn't the first time a TH400 has has ruined a motor.

 

If a moderator would please change the subject title to something like "454 thrust bearing failure" it would be much more accurate, I believe. When I made the first post, I was just a tad upset and hadn't investigated the problem thoroughly. My mistake.

 

It doesn't matter which brand of lifters you buy, if you look long and hard enough, you'll find someone that's had a problem with them. I'm not saying Comp is better than any others, it's just that I don't think their lifters are what caused this problem.

 

Dan

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unless something happened when rebuilding the trans it's highly unlikely it had anything to do with thrust bearing issues, the 400 is a gentle giant. More probable something is amiss in the lower end of the block, crank tolerances, clearances, main caps, alignment, crank run-out....etc...if line pressure was to high you certainly would have noticed it, it would have been slamming into gear quite brutally.... wink

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Thanks for the help, Davey.

 

"unless something happened when rebuilding the trans"

 

This is what I need to determine. The block was align honed in April.

 

Dan

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Was the rear of the thrust the only side affected?

When you pulled the engine, how much clearance was there between the converter and the flex plate?

 

By the way I changed the name of your post as requested.

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Thanks. Only the rear of the bearing is worn. I pushed the converter about 1/4" into the pump after unbolting it from the flex plate.

 

Dan

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