"Orval Fairbairn" wrote in message
news
In article IMJpk.70$482.47@trnddc06, "Dick"
wrote:

The specs for my C-85 are upper plugs mag @ 28* BTDC and lower @ 30*BTDC.

My results are upper @ 30* BTDC and lower @ 32* BTDC.

I couldn't find a "flower pot" with attached degree wheel to borrow and
attach to the prop hub so used a little "mickey mouse" circular
protractor
with a free swinging needle/pointer.

Two separate readings confirmed my 30-32. TDC was identified and impulses
unloaded before taking the readings.

My question is whether my results are acceptable for a low speed ,
experimental or need to be readjusted??

If need to be redone, I'd appreciate a little on why, please.

Thanks, Dick

PS: If listening G, I think "highflyer"(?) gave me some mag advice
during an "annual" a few years back which was appreciated.

Since you are probably using 100LL in an 80 octane engine, you are
probably just going to get a little more than 85 HP, with no damage.

--
Remove _'s from email address to talk to me.

Please reconsider your response. Detonation is not the only concern. These
old Continentals can built up of parts of unknown age, condition, and
history. Even when new, these engines didn't handle high cylinder pressures
very well. So even if the cylinder pressures are not high enough to cause
detonation with 100LL, they can still be high enough to pull cylinder base
studs out of the case, crack cylinder heads, hammer main bearings, and flex
or distort crankcases over time.

I'm not sure the OP's method for checking timing is accurate, but if his mag
timing is in fact 2 degrees advanced, it should be reset to the values on
the data plate.