Can you spot what's missing?
Discussion
Oh S$!t ,,,,,,guess mi factory 720 prize is on the back burner then Phil!
If you are rebuilding and replacing the cam, I would suggest one off Mike Jones. A proper piece with very nice radii and cam finish, not too expensive for the standard you receive.
Hows the block, do you know whats the root cause yet, oil pressure/bearing failure or just a snapped cam?
If you are rebuilding and replacing the cam, I would suggest one off Mike Jones. A proper piece with very nice radii and cam finish, not too expensive for the standard you receive.
Hows the block, do you know whats the root cause yet, oil pressure/bearing failure or just a snapped cam?
PB3: Could you expand on the situation a bit. What engine, who's cam, how much mileage. I keep seeing these horror stories regarding engines and from the west side of the pond it makes no sense at all. Even agreesivly tuned SBC last at least 30,000 miles I keep reading about examples of failures of fairly new motors. In the overall picture I still believe that running an Ultima at any where near its potentail of G loads wihouut Dry sump is a foolish idea. The cost of a well engineered dry sump on a SBC or LS is a very small number compared to the cost of an engine. Not to say that was the cause in this instance. I will say that if that's a after market cam from a quality company like Comp or Webb cams I think a discussion with them could be worth the effort. Sorry about this turn of events I am sure it didn't add any cheer to your holiday. Lee
Some info: AS 525hp, 17,500 miles, just over 1,000 on track, oil pressure lost on track. This is a Comp Cams custon grind cam, with mechanical roller lifters. Found no other reasons for oil pressure loss up til taking (part of) the cam out. Could just be a simple failure but will get block checked. This engine has performed well and taken a lot of stick over the last 5 years. The last 4 lobes and dist. drive part of the cam is still in the engine, it is loose. So far everything else looks pretty good and clean.
738 driver said:
Has it had the valve springs replaced during its life Phil?
No, untouched. Regular valve clearence adjustment and oil services etc. What are you suggesting? Followers, push rods, rockers all looked ok, not dismantled the heads yet. Are you thinking something has jammed the top end thus putting stress on the cam, that would prob mean bent pushrods would it not?Edited by Pb3 on Sunday 27th December 19:57
From the ones I have had in pieces, the A/S motors do have decent quality valve train (lifters/springs/pushrods/etc) installed but if there is nothing else apparent, it might be worth getting the springs checked too. If they start to lose control at elevated rpm the effects are transmitted straight back to the cam, in the case of a cast core this might cause its failure adjacent to a lobe or journal.
Also, did you notice whether the cam timing marks where aligned/condition of gear on stripdown, again with heavier duty valve gear, the chains/gears can sustain considerable wear with subsequent harsh operation centred around the cam!
Good luck
Also, did you notice whether the cam timing marks where aligned/condition of gear on stripdown, again with heavier duty valve gear, the chains/gears can sustain considerable wear with subsequent harsh operation centred around the cam!
Good luck
Cam timing looked good, the dots aligned with No 1 at TDC (by eye). Chain and gears also in good condition. Interesting what you say about the springs. The break is right next to the journal, here is a picture...
The high point (seen at the top in the pic) shows a polished finish, just like it has been turned against the other half, I suppose this is how the engine ran and had no oil pressure. But that would imply some cam walk, is all this possible???
The high point (seen at the top in the pic) shows a polished finish, just like it has been turned against the other half, I suppose this is how the engine ran and had no oil pressure. But that would imply some cam walk, is all this possible???
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