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Agree with patrick in that it's a timing issue ( although I have never seen 30 degrees of mechanical advance in a distributor before ). It sounds as though you have too much timing coming in too soon ( curve is too fast at the bottom end ). You can try replacing the light spring with a heavier one, or to verify that's the case, set the initial timing @ tdc or even a little on the retard side and see if that perks up the low end. It will obviuosly kill the top end ( and the vacuum )but it's just a test to see if the initial curve is too fast. For your set up, I would run about 12 mechanical degrees in the distributor ( 24 degrees @ the crank ) with initial timing at 12 degrees for a total mechanical of 36 dgerees - Curve to start around 1200rpm and all in around 2800 rpm. I'd run about 14 degrees of vacuum advance. This would give you a total of 50 degrees at cruise - 2800 rpm or above. Very common set up for a streeter.




all my degrees I mentioned were in crank degrees off of the damper, so the advance plate actually had 15 degrees in cam degrees, or 30 in crank. degrees.

you have it backwards. retarding the distributor will hurt low end, and move the powerband higher in the rev range, because at low RPM's the peak cyl pressure will occur after TDC with it retarded.


10-4 on the degrees patrick. Peak cylinder pressure ( flame front at its peak )in normally asperated engines should occur around 12 degrees ATDC ( best angle of attack between the piston / rod / crank). If you light the fire too early, this peak flame front pressure will occur too early ( before the 12 degree crank angle ) in the cycle and torque will drop off. If you are lighting the mix too earily ( especially at low rpm's, the motor will be flat. An easy test to verify this is to just retard the distributor ( sets the hole curve back ) and see if it feels better a low speeds. Again, you could also install heavier advance springs - or switch the heavy and light springs - temporarily.


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