Two models of this engine brand are known. They are due to Arthur Chevrolet, of Chevrolet Aircraft Corp, Indianapolis IN. (Another reference mentions: Arthur Chevrolet Aviation Motors Co).

"D-4"

-The first engine is the D-4 from 1929 with 4 inverted inline cylinders. It was air cooled and delivered 90/120 hp.

-The six-cylinder D-6 from the same year had the same layout and delivered 165/180 hp. This engine was air cooled and had a displacement of 508 cu. in. A test D-6 was installed on the Travel Air Mystery Ship air racer.

-Below we show two recently received photographs of the D-4 and D-6 engines built by Chevrolair Motors de Indianapolis.

-First the D-4 engine that gave 110 hp at 2,000 rpm, and 120 hp at 2,200 rpm. There is doubt about the variant of this illustration, as it is totally different (It is mentioned as a D-4 in a technical information, having a totally different architecture. Research continues.

-Besides, is it an inverted picture?. So it seems from the oil sump, carburetor, magnetos, etc.

“Chevrolair D-4?”

-Inverted or upright, it seems a nice engine. If it is not a Chevrolair D-4, information would be appreciated.

-The 6-cylinder D-6 delivered 165 hp at 2,175 rpm.

"Chevrolair D-6"

From Appendix 10: Chevolair ad in which Arthur Chevrolet (see Chevrolet) appears as president.

"Chevrolair Motors, Inc, ad"

-The D-4 and D-6 differ from the Chevrolet D-333 by the ribs on the crankcase cover, intake manifold, etc.

-However when they are manufactured under "Glenn Martin Motors Corp" (1931), they are renamed "4-333"

“Martin 4-333 ID-plate” (NASM)