TheJacobs R-915 orJacobs L-6 is a seven-cylinder, air-cooled, radial engine for aircraft manufactured in the United States, production started in 1936.[1]
The R-915 was effectively an enlargement of theR-755 with strengthened stressed parts.[2] With abore andstroke of 5.5 in × 5.5 in (140 mm × 140 mm), for adisplacement of 915 cu in (15 L). Take-off power was around 330 hp (250 kW). The engine features steelcylinders with aluminum-alloycylinder heads.