Dale,
If OP means original poster, that is me. For the record, my timing is 2 deg
more advanced but still BTDC by 32 deg. After an A&P rebuilt and installed
my mags about 100 hours ago, I'm not sure if they were installed per the
manual spec 30 deg or the 32 deg I found by test recently. A different A&P
doesn't have a problem with it either way.

I any case, I am just curious about any range established per "rule of
thumb", experience or paracticality..

Thanks for taking the time to give your opinion.


"Dale Scroggins" wrote in message
...

"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.