Lycoming O-435
6-cylinder horizontally-opposed piston engine family by Lycoming

The Lycoming O-435 is an American six-cylinder, horizontally opposed, internal combustion aircraft engine. Used on both
fixed-wing airplanes and helicopters, the engine is a six-cylinder version of the four-cylinder Lycoming O-290.
Design and development
The powerplant is a horizontally opposed Lycoming six-cylinder, gasoline-fueled internal combustion design. It is a direct-drive or geared, air-cooled, and naturally aspirated engine. The cylinders have steel barrels with aluminum heads, and the valves are operated by hydraulic lifters. The crankshaft is supported in an aluminum-alloy split case by four main bearings and one ball-thrust bearing, and lubricating oil is supplied from a 12 quart wet sump. The camshaft rides in journals that do not employ bearing inserts. The accessory housing supports two magnetos, a starter, a generator, and a dual tach drive. A spare mounting pad is included for a vacuum pump.
Variants
All engines have an additional prefix preceding the 435 to indicate the specific configuration of the engine.
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This entry incorporates text from “Lycoming O-435” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.