So I'm looking at a pretty nice Zenith 750sd. Thunderbolt O-360 in it. Brand new. When I try to do homework on the TB O-360 I get a bit confused -- there doesn't seem to be documentation specific to the "Thunderbolt" part --- but there is a fair amount out there about the O-360 part. It SEEMS like maybe mogas is fine on a carb'd 360 as long as everything non-lyc-360 supports it (pumps, lines, etc). Can anyone potentially school me on this? I'm not real smart on piston stuff.

flipfloplife wrote:So I'm looking at a pretty nice Zenith 750sd. Thunderbolt O-360 in it. Brand new. When I try to do homework on the TB O-360 I get a bit confused -- there doesn't seem to be documentation specific to the "Thunderbolt" part --- but there is a fair amount out there about the O-360 part. It SEEMS like maybe mogas is fine on a carb'd 360 as long as everything non-lyc-360 supports it (pumps, lines, etc). Can anyone potentially school me on this? I'm not real smart on piston stuff.

Sorry, I’m not real familiar with the “Thunderbolt” designation you refer to. Is that the Lycoming custom shop version, or something else? If Lycoming, why not contact their tech help folks? I’ve always found them helpful. If some other manufacturer, why not contact them?

Or have you already?

MTV

flipfloplife wrote:.... It SEEMS like maybe mogas is fine on a carb'd 360 as long as everything non-lyc-360 supports it (pumps, lines, etc). Can anyone potentially school me on this? I'm not real smart on piston stuff.

FWIW the Petersen Aviation mogas STC is applicable to the Lycoming O360.
It does require 91 octane (ethanol free) gas though.
The Zenair 750 is a highwing, but you have a fuel pump(s)? That complicates things.
I know their brochure says that different fuel pump(s) are required for Piper Cherokees.
And their airframe list includes several low wing airplanes that must require pumps of some sort also.

Why mess around with mogas on an airplane that burns so little. Unless you fly a couple of hundred hours a year or have no access to a gas seems like work and risk for modest returns...gas for my 182 is among the lowest cost categories of aircraft ownershi

I would 100% go with the mogas option in my location as LL100 here is $5.70 a gallon on good day.

All locations are not created equal

Airdave100 wrote:.....gas for my 182 is among the lowest cost categories of aircraft ownership.

I disagree, that's not so in my case anyways.
I fly about 100 hours a year, burning 11 gph (on the low side) that's 1100 gallons a year.
100LL at my airport is $5.28, that's $5808 a year
Local e-zero mogas is 3.19, that's $3509 a year.
So about $2300 a year savings.
I burn a mixture of about 80% mogas,
so actual costs are about 3.61/gallon--
that's $3,971 a year.
Fuel is my highest single line item cost.
I own my hangar, but even if I rented it'd be about 3600 a year for a nice hangar at my airport.
So fuel is still at the top.

Short answer is yes, but watch for vaporlock issues to be more common.

What is the compression ratio? DENNY