Cletus05

I've got an unusual problem with my car and I hope someone knows whats causing it. I have a 2001 Pontiac Firebird Trans-Am with an LS1 engine. I bought the car from a friend who did a H/C swap, had a lifter go bad after only being driven 4000 miles since H/C swap. Rebuilt, put in a new Cam, all new lifters, now have driven it 8000 miles and exact same thing happened. It appears the lifter wheel quit turning, causing the cam to grind the lifter down. I have ported LS1 Heads with Dual Rate Springs and a Texas-Speed 224/224R .581 lift Cam. WTF is going on with my lifters?

Orr89rocz

iTrader: (13)

what lifters you using? Possible bad lifters but since it happened twice its kinda unlikely.

Is it the same lifter thats going out? Is there oil blockage in that area so the lifter is not getting oil and locking up?

What are the spring pressures? I doubt you have too much but just curious

Cletus05

I put in Stock lifters

First time it happened it was the exhaust lifter on cylinder #2, this last time it was the exhaust lifter on cylinder #8

I haven't pulled the cam yet, but that's the only one I could see looking through the valley cover... so there might be more :/

Not sure of the Spring Pressure... I'll try to get a hold of the guy and ask him...

BaddBird

iTrader: (6)

I see you changed cam and lifters but did you change Prods? Did you measure for Prod length?

Cletus05

I reused the pushrods as they all looked fine... as for measuring them, I'm unfamiliar with the process or what it involves...

99blancoSS

iTrader: (115)

Contamination would be my guess or an oiling issue

Then there is this... its a stock lifter.. are you driving it so hard that your collapsing it with your aftermarket cam and spring package? If that is the case then you need to step it up tp.

Cletus05

I spoke with a mechanic who informed me that oil companys are no longer putting enough zinc in their oils. He said zinc was necessary to break in a new cam/lifters otherwise they don't get the proper lubrication they need...

As for the H/C setup causing the stock lifters to fail, its definitely a possibility but why does it only do it 1 lifter, while all the rest are fine?

BaddBird

iTrader: (6)

This is only true for flat tappet lifters. This will not effect rollers. If it was a break in issue or contamination I would think you would have more than one lifter fail at a time.

mr. Jones

did you replace the lifter trays?

did you clean the new lifters before installing them?
sometimes the roller is gummed up with a coating to prevent rust.

Cletus05

I did not replace the lifter trays... I thought the only thing the lifter trays did was keep the lifter from rotating?

As for the new lifters, I didn't clean them but all the wheels rotated freely... also the first time this happened it was to one of the original lifters that the guy who did the H/C swap put back in, this second time from the new set of lifters I put in... Same problem both times...

Cletus05

Ok so the car is getting repaired... new cam, new lifters, new pushrods... still don't really know whats causing the problem, but third times the charm, right?

ae13291

iTrader: (8)

wow man really sucks to hear that happen, could be a cause of bad preload on the lifter, what pushrod lengh is it?

KILLER-LS1

iTrader: (18)

you should soak the new lifters in oil for like a day before you install them

Cletus05

I put the stock length pushrods in there... but this time Its gonna get measured to make sure I'm getting the right length...

I'll definitely soak the lifters in oil for a day before they get installed... I'm willing to try anything at this point...

If anyone has any more ideas/thoughts/suggestions, let me know

vettenuts

iTrader: (4)

One word, Morel. They are more money but they are 100 times the lifter. Talk to 99blancoSS.

69LT1Bird

iTrader: (1)

His engine combo isn't aggressive enough to need Morel's.

Sounds like something is not being put together, cleaned, or measured properly. There are thousands and thousands of cars with cams (bigger than his) running the streets without issues.

LS1-450

iTrader: (33)

It's pushrod length. New install w/ measured length will solve the issue, IMO. OP says he re-used the same pushrods that were used w/ the original failure & states that stock length pushrods were used. This is likely not correct for the set up. One lifter is failing first; not to say that more lifters wouldn't fail soon after. They just haven't yet failed because you have stopped driving due to the failure of the first lifter. Stock LS7 lifters are fine for that set-up.

99blancoSS

iTrader: (115)

Its not just the lobe profile its the rpms involved. I agree you wouldn't think with this cam the rpms would be an issue. BUT if its seeing the upside of 5500 rpms more often than not it would be a concern.

XtraCajunSS

iTrader: (2)

Change the lifter trays. I've seen this problem more than a few times. The lifters are turning slightly which causes the roller to stop spinning. This happened to one of my customers 3 times before he finally changed the the 4 $8 plastic lifter trays.

The cam you have should be fine with stock length pushrods. I can't imagine them being far enough off to cause that issue. If you would like, I can send pictures of 3 destroyed engines caused by the same type of failure.

Thanks,
Shane

LS1-450

iTrader: (33)

Good point. Saw the question above regarding the trays & didn't consider why that question would have been asked. Never heard of it, but, it is now something that I will certainly watch for as my set-up ages. Thanks for the post.