OS-Speed Adam Drake AD4 .21 Off-Road Engine

OS-Speed Adam Drake AD4 .21 Off-Road Engine

OS-1FH00 OS-Speed Adam Drake AD4 .21 Off-Road Engine

O.S. Engines would like to introduce new O.S. SPEED B21 Adam Drake 4 - The latest collaboration engine with world famous O.S. Team driver Adam Drake.

After extensive testing, the piston, liner, crankshaft, outer head and head button have been redesigned to Adam Drake’s own specification to give better balance, more torque and more power for the best driving performance whilst maintaing the same, great fuel economy the previous Adam Drake edition OS engines are reknowned for.

The newly designed liner uses the same, tried and tested 3-port design, but features changes to the exhaust port dimension to increase torque of the engine. The crankshaft also has had the internal diameter reduced to give greater engine response at low-mid range whilst also increasing fuel efficiency. The new cooling head is similar to the original AD3 cooling head, but it features an additional cooling fin to increase cooling capability which helps the engine perform more consistently over the course of a run, especially in hotter climates. The head button’s combustion chamber has also been redesigned to improve effieincy and increase torque.

The Adam Drake AD4 engine comes supplied with both a 6.0mm blue anodized venturi and a 8.0mm blue anodized venturi. Adam recommends the 6.0mm being the best starting point for use in a buggy, offering good, mangable performance with good runtime. The 8.0mm is best suited for use with the engine in a truggy where maximum power may be desired, or on tracks where you need to maximize perofmance at the cost of runtime.

Specification:

Displacement： 3.49 cc / 0.213cu.in.
Bore: 16.4mm / 0.646 in.
Stroke: 16.55mm / 0.652 in.
Output :2.65 ps / 2.61 hp / 34,000 r.p.m.
Practical RPM range: 4,000-42,000 r.p.m.
Engine Weight: 352g / 12.42 oz

Includes:

OS Gold P3 glowplug, 6.0mm venturi, 8.0mm venturi, exhaust gasket seal & dust cap set (3mm/16mm/18mm).