jub jub

My lobes and lifters are starting to show that kind of wear after 8 thousand miles. The stock Z06 cam that I pulled out with 12 thousand miles and is smooth like a polished mirror, no scoring whatsoever. Same lifter trays. I'm wondering if it might have something to do with a poor quality of materials or hardening process of the Comp cam. My cam is also a Comp XE-R. Coincidence?

SideStep

Good point about same lifter trays not affecting the factory cam...

I think you have touched on something here... But, I do not think it is specific to CompCams. We (I mean the H/C crowd) are running some serious lobe profiles and increased spring pressures... Greater spring pressures, heavier valve-train and HIGHER rpms are what I think are the culprit... JMO... 8000miles does seem extreme, mine had 15,000... I really wish you had not had these results, I just installed a 226/230 XE-R on a 112LSA+1...

There are reasons GM went with lighter sodium filled valves on the ZO6... and I think we just might be seeing that reason now... not sure.

jub jub

Bingo...we have a winner!

A friend over on Z06vette.com showed me some pics he took of his G5X2 and lifters and they look just like yours. He was using stock lifters and blamed it on that.

http://www.z06vette.com/forums/showthread.php?t=94804

SPIV

That condition looks like "spauling" to me definately farked.

WS666

iTrader: (14)

Well, it now looks like I know what exactly happened to my motor... my cam and lifters looked exactly the same as those in the pics. My trays were #'d 11, 12, 15, & 16. I was running a T-Rex for about 25K miles.

Cstraub

iTrader: (1)

I disagree with you all and this is why. It is common in BBC marine applications to run cams in the mid 600 lift range with aggressive lobes. The weight of the valvetrain on a BBC is heavy to say the least, 3/8" stem valves, 2.300" diameter intakes and lengths of 5.400" is common. Spring pressure ranges from 140# to 170# seat pressure and over 400# at max lift. The lifters are the same diameter and in some cases the same lifter as what is run in the LS1. These engines see idle of 900 rpm and constant rpm of 3000 to 5800 rpm for the rest of the time. Springs get changed on these animals at about 200 hours. That is equal to 20K miles in a car. Cams are good and lifters see no wear issues like we are seeing on these LS1's. Something else is causing this and I have my opininon but I will let the experts tear apart one of these lifters and see what they say.

jub jub

Chris, I'd like to hear your opinion. If you like, you can PM me. I need to know before I make the same mistake twice!

1fastWS6

iTrader: (3)

I'd send the cam back to comp.....maybe the heat treat on the lobes wasn't right and caused it to ruin the lifters too.

cantdrv65

iTrader: (3)

As I have posted before Im using the stock Z06 lifters (47,000) miles....About 20,000 on them with the stock Z06 cam the rest a Comp XER lobe .588/.588 lift cam...I was running ISKY singles for about 27,000 miles now I have new heads with PRC dual springs. The lifters and cam were mirror finish after the first no wear whatsoever....If that cam was not ground totally smooth no matter the make when you orginally installed it it will wear the lifters....

Thats what I think is the cause...My cam and lifters both look perfect.

Cstraub

iTrader: (1)

Jub,
I have sent Sidesteps lifters off for analysis. I would rather have the experts look at them and see what they come up with.

jub jub

It might come to that.

I haven't removed my cam yet but I can tell from shining a flashlight through the lifter bores, it ain't good!

GuitsBoy

iTrader: (4)

What springs were those with lifter problems running?

I was running TEA gold dual springs with 140/350 pounds when my lifters came apart. Maybe I should test my springs to see what the acual tension was.

SideStep

I am using the base AFR springs I think they are 130/340. Like Cstraub said the lifters are on their way to analysis, we will see what comes from it...

GuitsBoy

iTrader: (4)

Also, another post just reminded me about this. Did those with lifter problems have cams that whine? When I installed my f-13 it whined like a supercharger under the hood. I wonder if the lobes were ground with ridges that ate my lifters... or maybe a harmonic broke them apart. Im just looking for a common symptom of killed lifters.

Cstraub

iTrader: (1)

I won't type it but you can call if you like and I will speak it. . .423 854 0007

Cstraub

iTrader: (1)

I have to disagree and this is why. Years ago I visted with a customer that built sprint engines. These were 700HP 410CID engines back in the mid 90's. This guy is still around today and is very well respected. My jaw dropped as I watched him SHOT BLAST a brand new roller camshaft's lobes. Not the journals just the lobes. Well I had to ask why. He said by dimpling the cam shaft lobes with shot he was creating oil retention "pockets" on the lobes. By doing so the the roller lifter wheel would have constant oil and he felt would get some "splash" benefit to oil the needles.

This guy has proubly built a couple thousand engines over the last 30 or so years and won many a championship. Since then I have had a few other "old school" guys tell me they do the same thing with great luck. Now with the introduction of pressure fed lifters you would not have to do this anymore but I can attest that a smooth lobe is not neccesary.

WS666

iTrader: (14)

I was running Crane Duals, no cam whine. The only way i knew there was a problem, is I was getting a tapping sound coming from dead center of the motor. Then I had a lil bit of metal shavings on my oil drain plug.

GuitsBoy

iTrader: (4)

Ill have to respectfully disagree here. A few months ago (roughly 6K miles) Was when I first tore up my stock lifters. After inspecting my cam, the one lobe was a little bit pitted. Nothing sticking up, but small pits were dug into the cam when the roller flaked apart. After inspecting the cam, i decided id take a chance and see if it would atleast get me through the rest of the winter. Fast forward to a few weeks ago, when I noticed the same rhythmic kerplunk sound coming from my lifters. I knew exactly what had happened. The brand new lifter that had been riding against the pitted lobe was torn up again. Keep in mind that the cam lobe was only slightly pitted, and did not have any sharp burrs or snags that would cut into the lifter roller. It still tore up the roller in 6K miles.

I feel that maybe there is some validity to sandblasting the cam lobes for oil retention in a racing motor, but not for a street motor that has to serve a long life.

jub jub

No whine here! My springs were the stock AFR.


BTW, you guys should give Chris a call!

1fastWS6

iTrader: (3)

I'll add this in regard to cam lobe 'smoothness'....I just replaced the solid roller in my BBC because several lobes had major pitting. Sent it back to the MFG and they replaced it stating it may or may not have been a bad heat treat on the core. The lifters look PERFECT still......no wear at all on the rollers. Prior to this incident, I would have thought surely the severity of the pitting would have chewed thru the rollers on the lifters.....and.....the springs I'm running are 250# seat / 825# open!