O.S. 91VR-DF Small Head

O.S.^® 91VR-DF Small Head

Features

Rear Exhaust

Schnuerle Porting

2-piece Crankcase

2-Crankshaft Ball Bearings

Rear-Mounted Carburetor

Drum Rotor Induction

ABN piston/cylinder (aluminum piston nickel-plated cylinder)

O.S. Ducted Fan Engines offer incredible performance and unsurpassed reliability. Designed to fit the popular ducted fan units, these ultra-high rpm engines feature ABN piston/sleeve construction for high compression and superior output. Developed to produce the high horsepower serious ducted fan fliers crave.

“Small head” ducted fan/jet engine features true “ABN” construction, dual bearings and bellcrank for the remote needle valve

High speed performance characteristics

Glow plugs are required

Specifications

Construction: Aluminum and Aluminum alloys
Displacement: 0.91 cu in
Bore: 27.7mm (1.09”)
Stroke: 24.5mm (.97”)
Max Output: 4.8 BHP at 22,000 rpm
Practical rpm Range: 2,500 - 25,000 rpm

Weight: 662g (23.4oz)
Length: 133.5mm (5.26”) from carb intake to front of drive washer
Width: 43.5mm (1.71”) neglecting the engine mounting flanges 52mm (2.05”) distance between the centers of the mounting holes
Height: 103.3mm (4.07”)
Crankshaft: 5/16-24