O.S. 55HZ-R DRS Ringed Helicopter Engine

Tower Stock# LXARVS  •  Manufacturer Stock# 15650
O.S. 55HZ-R DRS Ringed Helicopter Engine (large view)
Notes from our tech department:
This is the Limited Edition OS 55HZ-R DRS Ringed Helicopter Engine
with the DRS (Demand Regulator System).

FEATURES

DRS system delivers fuel to the regulator under constant pressure
for precise fuel delivery throughout the entire tank from full to
empty
Mounting position of DRS is perfectly in line with the carb for
consistent operation in all attitudes of flight
Same mounting bolt pattern as the OS 50SX-H Hyper
Dual needle 40L-R carburetor allows independent adjustment of idling,
hovering and high speed with four arm throttle lever for use with
a variety of servo brands
HZ Hyper low profile six fin cylinder head
Two year limited warranty through Hobby Services beginning at the
date of purchase

INCLUDES

OS 55HZ-R DRS Ringed Helicopter Engine, #8 Glow Plug, Check Valve and
Instruction Manual

REQUIREMENTS

10% to 30% nitro Fuel with at least 18% lubricant (Helicopter Mix)
Fuel filter and starting equipment

SPECIFICATIONS

Engine;
Displacement: 0.55 cu in (8.93cc)
Bore: 0.91" (23mm)
Stroke: 0.85" (23.5mm)
Practical RPM: 2,000-20,000 RPM
Output: 2.1 PS, 2.07 HP
Weight: 15.1oz (429g)
Carburetor Settings:
High Speed Needle Valve, Approximately two turns open from fully
closed position
Idle Mixture Control Screw, Factory set at center, turn right to
richen or left to lean mixture
Medium Speed Needle Valve, One turn open from fully closed, adjust
only after setting high speed needle and idle mixture screw, do
not turn more than 90 right or left
Distance/top of cylinder head-bottom of mounting tabs: 2.8" (72.6mm)
Distance between mounting holes same side: 0.68" (17.5mm)
Distance between mounting holes opposite side: 1.73" (44mm)
Distance between muffler mounting holes: 1.4" (37mm)
Cylinder Head Diameter: 1.8" (47mm)
Distance/bottom of crankcase to top of cylinder head: 3.6" (90.9mm)
Distance from center of engine to front bearing: 2.03" (51.6mm)
Distance from center of engine to end of Crankshaft: 3.2" (82.6mm)
Distance from center of engine to backplate bolt: 0.98" (25mm)
Distance from center of engine to throttle lever: 1.5" (38mm)

jxs 12/23/10
ir/jxs

Resources
See Tower Catalog page 174.
Easy RC: Engines
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