In article ,
Jim Carriere wrote:

Jay Honeck wrote:
Yesterday I noticed that we had pumped more than 5000 gallons of mogas
through the Mighty Grape. This represents something like 60 complete fills
(our plane has four gas tanks, totaling 84 gallons), and around 350 hours
of
flight time over the last 2.5 years.

Awww, anecdotal evidence. Statistically speaking, you need a larger
sample size

But seriously, a good post, well documented.

'Couple questions-

Do you use the same spark plugs (and same heat range) as before going
to mogas?


I do, too -- plugs last longer without the lead in the fuel.



Do you lean, and how lean? What kind of numbers do you usually see
in different regimes of flight (EGT, CHT)? Obviously detonation
hasn't been a problem for you, I'm curious how hot you can get away
with on that engine with regular auto fuel.


Detonation is NEVER a problem when the octane is correct. If the engine
is designed for 80 octane, it will happily drink 80 octane mogas or
anything else that meets the minimum spec. The absence of lead in the
fuel simply means that there is less junk to scavenge out of the
combustion products.

BTW, how many out there are aware that 80 octane unleaded avgas used to
be available, back in the 40s and 50s?

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