just as the topic says. how can you diagonis the problem or find the source? and how loud is a bent valve?

 

Bent valves don't make noise. They just cause a miss in the engine. Spun bearings freeze the motor up so will not turn over. Lash is higher noise. Lower clang is a rod knock or piston slap.

 

vacuum test at 3k rpm; compression test; and leakdown test can tell you alot.

 

vacuum test at 3k? how would i go about doing that? would using a auto meter boost gauge work with doing that?

 

Well actually I only know how to tell if piston rings are bad with the vacuum gauge. I was told that hooking up the vac gauge up to the intake manifold and run the car at 3k rpm and make sure the psi is within manu. specs (also considering your atmospheric pressure the psi may vary a little from the manual) and when u release the throttle (after running it at 3k), the gage supposed to go up a couple more psi before going back down=rings are okay. But if it doesn't go up before falling, the rings are bad. This diagnosis method is not always accurate they say though. Compression testing and cylinder leakage test is better.

 

If its valve lash you can tell that its clearly coming from the head if you put your ear above the valve cover and listen. If its piston slap you should know because you just changed your pistons. It doesnt happen to stock pistons unless they're the wrong size, which you should still know. Usually you can feel a spun bearing through the clutch pedal. When its on the floor, the knock can travel through and be felt at the pedal. It will feel solid but slightly faint. It can also be found by pulling plug wires one at a time until it stops. If it just happened try to fix it before it gets worse or dead.

 

 

Are you mixing up the throw out bearing and rod bearings? A motor won't last longer than 1 minute (if anywhere near that) with a spun bearing.

 

Mine lasted about 5 minutes Far enough to get me home, but I had to hold the revs up when stopped to keep the motor from stalling....

 

Yeah the first time you let off the gas it's freezes good. You must have had shavings everywhere.

 

looks pretty



crank was unhappy too