8.70:1 Compression/Mogas?

[D.A.]

We're going to run an Angle Valve 200HP Lyc 360 with the stock 8.70:1 compression pistons, but modified with a 78915 Sump and carb. It's only
.20:1 higher compression than the 8.50:1 180HP lyc's that run 91 Mogas. Is anyone running Mogas with this combination? What are the thoughts of those that have "Been there - Doing that"? With the Mogas that is typically available out there, would we be able to run Mogas in our 8.70:1 360?
Thanks in advance.

[Robert Anglin]

I have seen a few out there with this much "B.M.E.P.". The few I see and this is close to my likes and set-up, that is 9:1 use Hi-octane auto with no additives at all "corn or other" or 100LL. Also when you put in a hard clime it is a good idea to lower the nose a little to keep the head temp. down a bit.
If you have a new engine it is a good idea to keep it on 100LL, 60-100 Hrs. to start with before you start guessing at fuel blends.
Good luck an hope this helps. Yours as always R.E.A. III #80888