Push rod length and a collapsed lifter

8

85tr

Active Member
Joined
Aug 7, 2008
just put some ported irons on my car that I have worked on over the years and they have been surfaced twice. I used stock length push rods and now I found I have a collapsed lifter. Could to long of a pushrod cause this? I had no issues with the engine with around 5k on it with stock heads and only changed the heads now with only 400 miles with these heads number 2 piston intake lifter won't pump up. Thanks in advance.
 
Also if the cam looks ok could I get away with just a new set of lifters and shorter push rods if that’s an issue. Or should I replace the cam as well.
 
I'm not sure there is a direct correlation between changing heads and having a collapsed lifter. Even if they had been surfaced twice you typically take very little off when they are surfaced. It takes just a few thousandths of material removal to make sure they are square and flat. If the cam lobe looks good and the cam has low mileage you could probably just replace the one lifter and go thru a standard break in procedure. I wouldn't swap the whole set of lifters for new as you have 12 X more chance of something potentially going wrong. The conservative approach would be to replace the cam and lifters then mock it up with the stock length pushrods to see what the lifter preload is.

Neal
 
Thank you for the advice, I’m going to pull it apart tonight and will report back what I find.
 
Well after pulling both valve covers i found 6 of the rocker arms hade about a 1/8” of slack when the opposing valve was open. And the number 4 piston intake valve is barely moving. Guess it will be cam lifters and a prayer. Any suggestions on cam break in after loosing a lob ? Oil definitely has metal in it.
 
If it’s a hydraulic flat tapped then on first start up check for leaks bring up to 1500-2500 get it up to temp then let cool also should have a break in oil with lots of zinc after the first couple heat cycles u should be good to run her
 
U should replace the timing chain if you r swapping cams imo
 
Yea I figured that. Car never had a problem tell I put these heads on with new springs. Thinking the old soggy springs saved it and the new stiff springs were the culprit with no zink additive.
 
Unfortunately it sounds like you have a larger problem than you first thought. I was wondering if you have any specs on the springs that are on the heads you installed? If they are too stiff for a flat tappet cam the contact pressure between the lobe and lifter face will be too high an the cam will go flat. Since you said you have metal in the oil I would suggest dropping the pan and checking the condition of the bearings.

Neal
 
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Your engine needs to come all the way down to the bare block, knock out the cam bearings, freeze plugs, and oil galley plugs. Clean clean clean the block, then start from there.

You're radiator oil cooler is to be retired too.


I HIGHLY recommend going roller. Yes it's a lot more money, but It's cheaper to do it once. A small roller can work with stock rocker arms too.
 
Damn That’s what I was hoping not to hear. Car ran great before the heads but was a rebuiyblock I found on Craigslist so I’m not sure if the build quality. The springs are comp 980’s that I asked the head shop to setup up as close to 100lbs seat pressure as they could.

I could probably find the cash for a roller but was hoping to not pull the heads again. Thanks for the help guys.
 
Pulling the heads are the least of your worries. They'll pop right off when you get the engine on the stand.

Right now you're dealing with very few unknowns since a wiped cam is pretty much catastrophic.

The main thing you need to think about is what basic degree of budget you want to end up with. You know you're going to need bearings, gaskets, freeze plugs, etc... When it comes to cams, the major price point is roller .vs flat.

The unknowns you're stuck with are block, crank and rods condition. The only way to know the answers to that are to get the engine torn down and measure.

If your cylinders are worn, tapered, or just in bad shape, new slugs are in your future. With any luck the crank will polish out and the rods are round enough to dress and keep in service.
 
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Thank you for the knowledge, engine will be out by the end of the day.
 
Got the manifold off this morning and the cam looks good. 7 lifters were bad or soft but no damage to the bottom of the lifter or cam. I’m still going to check the bearings and go roller cam. Thanks for all the help.
 
85tr said:
Got the manifold off this morning and the cam looks good. 7 lifters were bad or soft but no damage to the bottom of the lifter or cam. I’m still going to check the bearings and go roller cam. Thanks for all the help.
Click to expand...
How are you determining 7 lifters are "bad or soft" yet the cam is still "good" ?
 
I was able to compress the lifters the other 5 were solid. There is no wear or damage to the cam or the bottom of the lifters. I will post up some pictures of the cam and lifters.
 
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