Pratt amp; Whitney R-2800-57 Engine Trainer Manufactured by the G.W. Holmes Company. Refurbished y Northland Aerospace Students: Rick Rohwedder and Doyle Fountain Jr.
Northland Community amp; Technical College, Northlandaerospace.com

The Pratt amp; Whitney R-2800 Double Wasp is an 18-cylinder, town-row engine with a geared propeller drive and a one-stage, two-speed super charger. It was one of the mostly widely used of all radial, air cooled engines. Designed in 1937, this engine powered many military and commercial aircraft. It was used in several key WW-II aircraft including: Consolidated TBY Sea Wolf, Douglas A-26 Invader, Grumman F6F Hellcat, Grumman F8F Bearcat, Martin B-26 Marauder, Northrop P-61 Black Widow, Republic P-47 Thunderbolt, Vought F4U Corsair. There were a total of 125,334 R-2800 engines produced.
Cylinder Diameter (bore) 5.75quot;
Piston Stroke 6gt;0quot;
Compression Ratio 6.75:1
Overall Diameter 52.8
Overall Length 81.4quot;
Dry Weight 2360 lbs.
The R-2800-57 engine produced 2,800 HP (2,090 kW) at 2,800 RPM.