Vibration Problems?

Follow Up

The guys that told me detonation was the problem was right. Too much timing at 34-37 deg. for the amount of fuel.

In another thread I asked what would cause five of my exhaust valves to leak. Same culprit - detonation. Detonation caused me to replace four exhaust valves and two intake valves!

I plan to put the heads back on, after the valve job, and check the leak-down again. I hope the piston and rings are ok. If they are, I'm going to set the initial timing at 30* to start with.

Thanks for all the input. Joe

 

when you tear down your motor look at your top ring around the edge with a eye loop to see if you see any flaking look to it if so ...yep you have detonation..Dave

 

sure sounds like detonation fatten it up but what do i know i quit counting the money i spent years ago because i didnt know what i thought i knew so i leave a little color on the plugs and not so frosty i cant tell how lean it really is with out a computor to help

 

Vibration

Your crank is crack
Denis

 

Not sure exactly what combo you are running, but with our hemi, with a screw blower, we typically run 26 degrees max with an MSD44, we have been up to 28 degrees with the roots. Back in the day of the mallory mag, we would run 40 degrees with a single mag, 34 degrees with 2 mags. That is how much better the MSD is, so be careful. I always thought chevy's wanted less timing than a hemi, as the bottom ends tend to come apart with too much?

 

I would also check clearance on your gear drive cover to the gears as B.Doucet said. I had the same probblem last year and it was becasue the gear drive cover was making contact with the cam gear. I clearanced the cam cover and the problem went away.

 

better take a good look at your top rings under a eye loop...I bet you will be surprized there will be flaking...dave