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A/C question

AirAg, there four letters used ..... I,G,S, and O as prefixes to the number, which is the cubic inch displacement of the engine.

An O540 is an 'opposed' cylinder, carbureted 540 inch engine.
IO means injected, opposed cylinder
ISO means injected, supercharged, opposed.
IGSO means injected, geared, supercharged, and opposed.

Radial engines use an R (for radial) prefix intead of an O, as in R985.
That would be a 985 cu. inch radial A/C engine.

Thanks, Swamp, forgot that one ..... like Cajun said in another thread, gettin' old ain't for sissy's. :lol:

For the Lycoming Engine There are a few more.

T also means turbocharged
L engine is left turning
A engine is designed for aerobatics (dry sump)
AE engine is designed for aerobatics (wet sump)
M engine is designed for unmanned drone
H engine is designed for helicopter installation (horizontal)
V engine is designed for helicopter installation (vertical)
X x type engine (I think for experimental, not sure)

Pirate, I've seen engines advertised for sale that they say had the "H" heicopter cam in them. What's the advantage of that cam in an airboat .... is it for more torque? Thanks.

From what I've been able to find out that's correct. The lobes of the cam keep the valves open longer if I'm not mistaken. You might ask "Jim" or "Thunder" about cam duration. I'm not that much of a motor head. I just work on my own engine. I run an O-360 Lycoming and the crank and cam are from a IVO-360.