[Tomas J]

Hi,
My engine is a O-320-E2D, but with high compression pistons. If I got it right, it is now an O-320-D2D. I've looked around to find the spark advance that the engine should have - but did not find it. If someone can give me an idea of where to look, I would be happy.

 

[Kyle Boatright]

My 8.5:1 o-320 d2j is timed at 25 btdc, which I think is standard for that basic engine planform.

Hope that helps.

 

[FlyingArcher]

O-320-E2A here

My engine data plate says 25 degrees. If you can find yours, it should be stamped on it.
See pic below.

 

[Tomas J]

The engine is modified

Daniel,
Thanks for your comment. Yes, the plate says 25 degrees, but it is for an E2D with low compression pistons – now with high compression pistons I'm not sure it shall be the same. I have just started up the engine and I feel it has a hard run with vibrations.

 

[FlyingArcher]

25 btdc too for D series

Hi Tomas,

Sorry about the picture size, I didn't realize it was so big

I've checked the Lycoming operator manual for spark advance settings on D-Series engines and they are also 25 btdc.
See page scan below

Maybe some engine experts out there will chime in to give an explanation on what you experience, but your current spark advance seems to be standard for high compression engines