Do you use 87 Octane Mogas ?

None of the Pmag users have answered my question on a different thread.

I have 2 Pmags on a 150HP 0320 w/7:1 pistons. Used 90 Oct Mogas for 250HR.

Emag air says the A curve tops at 34* BTDC. Nigel Speedy says 28*~ ROP is about all you need.

My 3B has plenty of power and I fly low, so why not just use 87 Oct mogas ?
Does anyone have EXPERIENCE with Pmag A curve using 87 Mogas?

No experience with a P-Mag - have burned tons of 87 in my C85 engine, until we started getting alcohol in it here.

BUT I do have a P-Mag on my O-360. If you're worried about advance and octane, you can program your P-Mags with either of the two programmers available in the aftermarket world, or you can just manually time them with the timing mark NOT set at top dead centre to create artificial timing "retard" rather than advance. A couple of degrees of retard is pretty common. I'm sure others with experience in setting retarded timing will comment here as well.

(Please, no comments about my "personal timing" being somewhat retarded - I already know, everybody tells me that all the time! )

Larry DeCamp said:

None of the Pmag users have answered my question on a different thread.

I have 2 Pmags on a 150HP 0320 w/7:1 pistons. Used 90 Oct Mogas for 250HR.

Emag air says the A curve tops at 34* BTDC. Nigel Speedy says 28*~ ROP is about all you need.

My 3B has plenty of power and I fly low, so why not just use 87 Oct mogas ?
Does anyone have EXPERIENCE with Pmag A curve using 87 Mogas?

Click to expand...

If it helps, Single PMag A curve, 89 from WaWa no issues O-320-E2C 150hp

RV-9A, IO-360, dual P-Mags w/jumper wire, 2260 hrs, 87 mogas no alcohol. The only av gas has been when on the road. I do live at 5000' (can't make 75% on the ground). Dan from Reno