Woah - I wonder now after reading this thread if my newly-built /6 has too much compression. I decked the block 0.050", and the heads 0.030", aiming for about 9.5:1 compression. Pistons are +0.030", too.
All six cylinders are within 3.5% of each other, with an average of 194 psi. Wet. Throttle tied wide-open. High-torque starter from a late-model Dodge V8 motor. All spark plugs removed for the testing.
It's only been driven for 10 miles, and I know the stock distributor is having problems that I suspect are tied to the centripetal weights seeming to have worn springs. Even with the adjustable bracket at the bottom of the distributor bottomed-out in its slot, I couldn't get base timing at idle to be less than about 8 degrees BTDC. Was aiming to get 0 or 2 degrees (with vaccuum line disconnected).
And it's got fairly bad 'clatter' / pre-ignition at wide-open throttle. With 89 octane fuel only, so far.
Wondering now if I did the math wrong and ended up with a 10.5:1 motor??
I have a rebuilt distributor I'm installing in a few days. Be curious to see if it helps.
