Most certified aircraft engines that can burn 87 octane Mogas require nothing
other than the STC paperwork. However, there are several caveats.
If it has a Stromberg NAS carb, you need to ensure that it has the Delrin
needle valve instead of the rubber tipped metal needle valve. The Delrin
needle valve has been the standard for decades, but I have seen the rubber
tipped ones available for purchase and have run across them in service.
If it has a Marvel Schebler carb, it must have a metal float, although I think
the composite floats should have all been replaced by now.
There can be compatibility problems with rubberized parts within the fuel
system.
Some engines shouldn't be run on Mogas. My Lyc O-235-L2C was a 100LL engine
before I installed the higher compression pistons to make it a O-235-L2C(M).
The lower compression Lyc O-235-C is OK to run on 87 octane Mogas. The small
Continentals, A-65 through O-200 are all OK to use 87 octane mogas in their
stock form with the above caveats.
While there may be some exceptions, I've never seen a mogas approval for a fuel
injected Cont or Lyc engine.
The Mogas used for aviation may not have any of the oxydizing additives such as
Alcohol or Methyl Ethers which are commonly found in that gas at many gas
stations, especially during the winter months. There are simple ways to test
your fuel for the oxydizers.
Probably more information than you wanted to know.
-Jeff
-- "Robert L. Stone" <rsto...@hot.rr.com> wrote:
Does anyone know what the procedures are to convert an aircraft engine
such as a continental or Lycoming to use auto gas and if so what auto gas
octane is recommended.
Bob Stone, Harker Heights, Tx
rsto...@hot.rr.com
