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Cam Timing Sprocket

New:04/07/2006


Hi everybody. Hope you are all well..
I bought another SHO a few days ago, this one is my 9th. And my second V8.
When I took this one apart, I came across something I haven't seen before. The cam on the front head that has the timing sprocket bolted to it, sheared the locating dowel in half. The only thing I can think of is that when the last guy did the repairs, the timing sprocket bolt must have been left loose. There is no locktite on the threads of the bolt.
Anyone ever seen this before?
Thanks!
Curt

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Never seen that before myself. Don't recall seeing locktie on mine. I could imagine that one of two things happened though: As you surmised the bolt was left loose enough that the alignment pin took all of the torque causing a failure or that cam lost oil pressure on it's bearing surface and locked up BIG time, not as likely but easy to see as that certainly would leave a mark on one of the bearing surfaces.
Carter Fuji

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Welcome to the head gasket (and bolts) club... Hang on to your wallet, especially if you like taking flight. Haven't heard of your scenario before, but result is the same, except you are talking about up to 16 bent valves, not just a max of 8.

Scott

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Kirk mentioned one of these "External" Failures where the OUTER Chain
loses timing with the Primary sprocket. IIRC it was about 2 years ago.
Not sure if the Motor was seized or some Mystery Metal stopped the
pistons or what.
I DO Recall it was NOT the Inner Sprocket that cut loose.
Yeah - Scratch 16 valves when BOTH cams stop.

IMO - This is A cam related failure, But NOT one of "OUR" Failures
and, if counted, should have an asterisk * attached to it. Similar in
results but entirely different in Source.

Erick Lehmann

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Welcome to the head gasket (and bolts) club... Hang on to your wallet, especially if you like taking flight. Haven't heard of your scenario
before, but result is the same, except you are talking about up to 16 bent
valves, not just a max of 8.
Scott

_________________________________________________________________________ 
Hi everybody. Hope you are all well..
I bought another SHO a few days ago, this one is my 9th. And my second V8.
When I took this one apart, I came across something I haven't seen before.
The cam on the front head that has the timing sprocket bolted to it, sheared
the locating dowel in half. The only thing I can think of is that when the
last guy did the repairs, the timing sprocket bolt must have been left
loose. There is no locktite on the threads of the bolt.
Anyone ever seen this before?
Thanks!
Curt

__________________________________________________________________________
Yeah.. The cam journals didn't look bad, so there was no lock up failure. Must have been left loose. I think I can get the broken locator out of the cam, and somehow use it again by installing another tempered pin, then maybe tigging the sprocket to the cam to be safe...
Actually just the front cam bent all the ex valves, the rear remained running and untouched. thank goodness!!
Curt

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The front cam drives the rear cam on that head with the slave sprocket, so if the front cam stopped rotating, the rear cam would HAVE to stop tuning as well. Interesting, Are we talking a V8SHO motor here?

Carter Fuji

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*can somebody translate for poor old Uncl Lar:{Iprobably did it twice, but have blocked it from my memories of that cold &ss garage.

U. L


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