Found my problem. It was the vent. I have one of those remote anti-turn over vents connected with a hose to the outlet on the tank. The line had gotten pinched close because of the way I routed the hose. Duh!
you can always check timing using vacuum method, attach vacuum gauge to manifold adjust timing to max vacuum then back off 1in of vacuum.....
Doing timing that way sets the initial timing, usually to a greater advance than stock, but mioves the entire curve the same amount and may well result in too much advance at speeds above idle. Many rodded engines do like more static advance, but part of the mod involves shortening the total curve...
I tryed the springs that bubba sent and it helped the ping some. Its still there only at at higher speed or heaver load. lost some performance at low rpm. after trying serveral combinations the day was over .I think I'll fatten the engine some and see what happens. hope to get the performance back.
On the timing: Roughly plot total available mecahnical advance by making up a cardboard degree wheel to fit around distributor, twisting rotor. Put in weakest springs, revvitup, verify total--vac can disconnected for this testing phase Need to worry about how much static setting is appropriate, curve might need shortening or moving around on low speed...flatheads need advance to kick off right above isle, move up quickly. Likely you will need the light springs as foundation point.
How much is the stock head to piston clearence..... More than 0.065 I think and stock motors don`t ping....
Re; plugs.... I put the usual H 10 in mine..offy heads,..and it ran like ****, off idle. The plugs were too short, being recessed almost a 1/4" in the heads...and that resulted in a lot of ping under even light load. I went to NGK plugs, that have same heat range, but long enough reach to match the Offy heads,......... Runs great now ! I run a Mallory electronic ign, and timing at 10 degrees initial. 4TTRUK
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