On 24 Mar 2008 20:05:49 GMT, Robert Moore
wrote:

Sushidot wrote
..what does the H2AD mean for the Lycomming o-320-h2ad as
well as the "o" in the front of the 320?

320 is the size (cu.in.) of the engine, h2ad indicates model differences,
and "O" indicates that the cylinders are "opposed" rather than "inline" or
"radial" or "Vee".

The "H" engine was one of Lycoming's worst products, bad camshaft material.
Numerous failures early in it's life with the resulant FAA Airworthiness
Directive requiring a special oil additive. Pretty much a non-issue now
since most major oils have this additive as standard.

I've got about 2,000 hours with an "H" engine without a single burp.

Yea, the stuff after the size tells mechanics about engine and
preinstalled accessory oprions (roller tappets, multiple vaccum pumps,
alternators, etc), most of it is pretty esoteric for the guy pushing
the throttle. You can also run into IO- engines, they have fuel
injection instead of carbs.

Good luck on the test!