1972 ZQ3 (350/200) Question

[jbeidl]

Does anyone know if this engine was an "interference engine" (Would the valves and pistons crash if the cam was out of time with the crankshaft)?

John

[bradfordsvettes]

I doubt it wold bend the valves it realy depends on what the engine was doing when the chain failed steve

[jbeidl]

Thanks. I had this issue with that engine after I had the heads rebuilt (valve guides, seats, valves and springs - oil was getting past the guides). Shortly after the heads were installed the camshaft timing gear broke - it was a fiber gear. I guess it could not bear the strain imposed by the new springs. I replaced both the gear and the timing chain.

This happened just after leaving my driveway during a 2-3 shift. After that, I could hear a very slight tick at idle that I could never find. I removed all of the push rods and verified that they were not bent.

The only thing I could thing of was that this was an "interference engine" and one of the pistons touched a valve and slightly bent it. The engine seemed to run just fine, only that annoying (to me) tick. I guess it is possible that the tick was coming from the new timing gear and chain. I will never know.

Thanks for taking the time to reply,
John