New engine noise

milo · Post by **milo** » Sat Dec 14, 2002 3:05 am

Yesterday I spent the day tearing down my 1680 only to find a bolt jammed between the seat and the valve.. (Last time I let a friend work on my car)... Anyway, I managed to grind the seat back, and lap the valves into it.. So, no biggy.. I decided while I was at this point I would pull my spacers out and raise my compression from 6.9:1 to . To do this I removed my barrel spacers and had .060 remain deck height (Which is plenty).. I honed the cylinders and put it back together, using the same rings since they only have about 2-3 thousand miles on them and they are soft cast iron rings.. I then lapped all the rest of the valves in a put it back together.. Now, the car runs great but when you accelerate you can hear what sounds like valve clatter.. until you hit high rpms that it disappears.. You can't hear it at idle or on deceleration.. Just bottom end acceleration.. Any ideas??

Thanks
Nathan

PEPPE · Post by **PEPPE** » Sat Dec 14, 2002 3:46 am

detonation?
check your plugs if they are too cold or if advance is too much at low RPM (typical with a 009). if so install a stock vacuum/centrifugal distributor

kafer-cup · Post by **kafer-cup** » Sat Dec 14, 2002 7:15 am

Also my first thought, you do have a higher comp. ratio now.
KAFER-CUP

p.s. double check valve clearance?

milo · Post by **milo** » Sat Dec 14, 2002 1:19 pm

I checked the valves.. Havent checked the spark plug.. The car runs REALLY good.. So, it can't be anything major.. I replaced the intake that got jammed against the nut with a new one and the guides were like brand new.. At first I was worried that it was a broken ring.. But, I just don't see how that could have happened..