ezstriper

how about checking the rocker arm geometry ??

HighPriority

We have been running the tall lifters for some time now. We checked the geometry and for pushrods lenghts, and made the proper adjustments. We have not pulled the heads, but we did a leak down test, and had less than 2%, so we are thinking the valves are ok. We had over 100 thousands valve to piston.

Thanks guys for ideas and help.

BillK

HP,
I thought about something else to day at the shop. A year or so ago I was doing a pair of 502's and we had two sets of lifters that seemed to be made wrong. When you put them in the block, they were not tracking perfectly straight on the camshaft. We sent them back to the manufacturer but never did hear what they found on them. It was almost like the link bars were not quite formed properly. We ended up using the factory type lifters, but the tall ones, with the factory "dog bone" retainers and never had a problem. Might not be a bad idea to look at the other lifters you have to se if they look straight. We never ran the ones we had but I would imagine they would have put some side loadings on the link bars if we did.

Bill Koustenis
Advanced Automotive Machine
Waldorf Md

BenPerfected

HP,
I think Bill could be on the right track. Last fall we had a catastrophic lifter failure. All 16 .850 rollers lifters simultaneously failed at 12 hrs....$12,000+ problem! The problem became apparent at a 5800 RPM high speed cruise...lots of damage. Best oils, perfect machining, spot-on clearances, assembled by a pro, .165 custom pushrods, SpinTron tested, best springs, retainers, valves, etc. How could this proven race set-up/combination fail at a fast cruise in flat water? Initially we thought it might be a bad cam core, we had it Rockwell tested and eliminated that...looked closer, it was clearly the lifers. After a little G2 and confrontation with the manufacture, they admitted the problem.
It would be my suggestion to get someone real experienced to help you with the diagnosis. Look real close at the surviving components for abnormal wear.
If it is a quality issue, you can get compensation. If you network, you might be able to find others that have had issues with the same components.
As others have said, many things can cause valve train failure, get a pro involved in finding out why.
My point is, don't assume it is not the product.

HighPriority

Now I have one hell of a problem, I'm no pro engine builder. When you say not tracking straight on the cam, were the lifters trying to turn side to side, rather than go straight up and down? What is the best way to check for this?

Thanks you very much for your help!

BillK

HP,
The lifters that we had were actually a little "twisted" for lack of a better word. It was as though the link bar was not bent quite enough, or maybe too far, I can't remember right now. It would have made the roller run just slightly sideways on the lobes. I noticed it when I was installing the lifters. You can see where they hit the cam on a big block, and they were not quite straight. I thought it might be the blcok, so we tried them in another block, but they were still crooked. I dont have my camera at the shop, but I will try to bring it on Wednesday and put a lifter in a bore and show you how it was twisted.

Ben,
If you feel like it shoot me an e-mail ..... [email protected]

Bill Koustenis
Advanced Automotive Machine
Waldorf Md

HighPriority

Well this goes to show how much I know about this stuff, I though they did have a LITTLE twist in them because the ones I have do have a little twist in them, by that I mean the lifter roller does not run perfectly straight, maybe a 1 or 2 degree angle on them. I can see this when you put them in the block. With the lifter straight the roller is on a very small angle with the cam.

searaycer

sounds like your problem they should run perfectly straight

HighPriority

The body of the lifter does run straight, but the roller is on a angle.

BillK

HP,
That sounds exactly like the ones we had.

Bill