BAD CAM BEARINGS...After Head/Cam etc
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From: Sumter, South Carolina
BAD CAM BEARINGS...After Head/Cam etc 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.
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Originally Posted by ramairstyle00
that sucks man. sorry to hear it. how do you check to make sure you have the right size pushrods?
Originally Posted by vettenuts
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.
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...
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From: Sumter, South Carolina
Originally Posted by vettenuts
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.
