91 and 100 octane fuel

[Zacke]

Hey guys,

I'm going to do an around the world trip with the P40 and want to simulate the limited availability of fuel in remote locations.

The question is: Where are the P40's limits with 91 octane fuel? With the Spit the limitations were quite clear via manual and forum.

Any suggestions here for the 91 octane fuel with the P40?

Thanks in advance,
Zacke

[ratty]

Interesting question. I'm going to do more research, but the limitation is the maximum manifold pressure you can safely use. At sea level in the P-40 you can apparently get up to 41"; with 91 octane I would recommend going no higher than 35" with a rich mixture, and lower than that when you lean. Since you don't have an EGT gauge, keep an eye on the coolant temp, which will be higher than normal if you're experiencing detonation.

[ratty]

Or you could poke through this:

https://www.docdroid.com/ibKHk6m/curtis ... df#page=10

Excerpt:

[Zacke]

Thanks ratty!

[ratty]

Thanks ratty!

You're welcome! The image in the other post was this: