BadAssFast

iTrader: (2)

Well this has been a long month. After swapping out head/cam apparently the combination of AFR205 stock, FM13, CompCam OE lifters, 7.4 PR, New LS6 oil pump and stock rockers wiped out my cam bearings. I'll keep a long story short. If your swap cams you had better check your preload and be sure you have correct length push rods. All this was supposed to work together without issue. I wil not blame anyone for my situation, but vendors who specialize in cams, in my opinion should spend a good amount of time on the importance of preload. I don't the subject ever came up until after I had bad lifter noise. Any way, cam bearings shot, nw OE Comp Cam lifters shot. Check you preload folks. Chances are the bearings were on the way out and the extra load from the 0.05 extra length and ~400 lb springs killed it.

chpmnsws6

iTrader: (70)

that sucks man. sorry to hear it. how do you check to make sure you have the right size pushrods?

DaddySS

Strange. I can see preload issues wiping out lifters, cam lobes, rockers, etc. but cam bearings?

vettenuts

iTrader: (4)

400# springs? How did you pre-lube the bearings, etc.? I would think too long a PR would hang a valve open but not take out a bearing.

BadAssFast

iTrader: (2)

Check pre load at install...too much ...too long is how I understand it.

I probably described the springs incorrectly...they are what AFR sells with their heads perhaps Patriot Gold? Anyway good for a bit over .600 lift.

As I said the cam bearing must have been going bad and our guess is that the extra PR length did in the lifters and the extra load pushing against the cam from the heavier springs against the pushrods > lifters > cam possibly hurried up the wear...probably happened at initial startup...certainly happened in about 50 -75 miles because that's all I got on it. Super close inspection of the stock cam reveals a bit of scaring...real slight...we didn't notice it until we looked. Whatever happened we had great oil pressure...good p/u tube O ring, all the typical issues that possibly come up. The engine had 63,000 of racing with a 150 shot on the last 10,000 or so. Main thing to restate is that I don't blame any companies...I've said, although Futral can be tough to get ahold of they are great guys in general and I use a FM13 cam. AFR got me real straight on lifter pre load while I waited for Allen to get back with his pre load specs. I have good add ons...soon I'll have a stroger core motro for them. I do think all vendors and manufacturers should stress the importance of checking pre load and push rods length at the time of the sale...anyway...this whole thing has given me a date with a 408 as they say...I'm a lucky man. I have my health and family...

BadAssFast

iTrader: (2)

Forgot to answer your initial question. My mechanic has installed hundeds of cams. He uses an appropriate lube at install. There was an appropriate oil change before the car was driven. We did trust the 7.4 push rod to yield a good pre load...turned out we needed 7.35. Anyway...I gues the dial indicator and adjustable pushrod check kit from Jegs was a bit late. LOL.