O.S. 91VR-DF 17511 Small Head OSMG1891

O.S. 91VR-DF Small Head OSMG1891

The O.S. Ducted Fan Engines are designed to develop high power at high RPM.

These are used in Jet (ducted fan) Models where the engine drives a turbine-like impeller (compressor) that draws a large quantity of air through a shroud to create thrust.

These engines are NOT covered under the O.S. 2-year warranty.

Because this is a high-performance engine, reliability is sacrificed.

The Ducted Fan does NOT come with this engine. One must purchase the fan to fit BOTH the engine size and the specific plane

Features

• O.S. 91VR-DF Small Head OSMG1891

• Rear Exhaust

• Schnuerle Porting

• 2-piece Crankcase

• 2-Crankshaft Ball Bearings

• Rear-Mounted Carburetor

• Drum Rotor Induction

• ABC piston/cylinder (aluminum piston with a chromed brass cylinder)

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 mounting hole centers

• Height: 103.3mm (4.07")

• Crankshaft: 5/16-24

Package Contents

• One Assembled .91 VR-DF Engine w/small head

• One Set of Instructions and Poster

• One Exhaust Adaptor w/screws and O-ring (OSMG2709)

• Bellcrank for use with the remote needle assembly (OSMG7258-comes with the engine!)

Requirements

• low Plug (O.S. #8 or #9 (OSMG2691 is recommended)

• Tuned pipe

• Fuel with 20% MINIMUM lubricant content and 20%-50% Nitromethane

• Wildcat Ducted Fan fuel exceeds these requirements

Comments

• This engine is the "small head" version of the .91 VR-DF engines.

• This engine is designed to operate where space is at a minimum.

• This engine works w/ Dynamax or Turbax fan units.