BB ingnition timing

got some free time this afternoon, decided to do some test today:

initial is set at 15° btdc, fully advanced it´s around 45°....i think the problem is that no one took care of this dizzy. I retarded the timing to around 10° at idle......little less power, but the pinging is gone! ok, that was easy.....

So it seems that the distributor needs a limiter kit for the mechanical advance, maybe i try welding / filing the slots until i reach the goal. Can anyone supply the length of the slot for 20° mechanical advance?

My buddy found the build sheet from the engine shop: cranking pressure is between 185 and 195 psi according to the sheet (warm engine). Cyl. chambers are 88cc, i found that KB237 Pistons are used (.040"), should be little below 10:1 compression (i don´t know the head gasket compressed height). Should work, what do you think? The shop told him he´s over 11:1 compression with this pistons....i think they are totally wrong.

It seems to run good if the full advance is limited to 35-40° (no more pinging..). It runs a little better if the initial is higher, will do some more testing even with the vacuum canister and limiting the total advance. Thanks for your tips!

Michael