The 3701 ES is a liquid cooled, reed valve controlled 3-cylinder-inline-2-stroke engine with electronic injection and Nikasil coated cylinders. It has one of the highest power to weight ratios available on the 100 HP engine market. Ideally suited for Ultralights, hovercraft, gyrocopters, light experimental aircrafts and all applications where weight is an issue.
SprintAero offer it with dual ignition, manifold fuel injection, Oil injected lubrication, the gear box G40 with a rubber isolator. We also include the recommended radiator in kit.
With a narrow engine profile and with a single tuned exhaust used for all 3 cylinders this allows the 3701 to be used in compact engine compartments. With the Pistons firing every 120 degrees the power is very smooth. The 3701 also has real world fuel consumptions to rival similar Hp 4-stroke engines.
The factory recommended TBO is rated at a real world 1000 hours at 75 % power. The warranty of the crankshaft is 3 years.
Technical data (Specification subject to change without prior notice)
Type: Three cylinder two stroke (inline)
Displacement: 939 cm3 (57.3 cu in) Stroke: 69 mm (2.72 in) Bore: 76 mm (2.99 in)
Max. performance: 74 kW (100HP) at 6000 rpm According to DIN 70020
Max. torque: 120 Nm (88.4 ft.lb) at 5500 rpm
Carburation: multi point injection
Ignition System: CDI Generator power: 250W ( dual spark plugs ), 12V
Cooling: Liquid cooling
Weight: under 71 kg installed package weight
Starting device:Electric starter
Running direction: Counter-clockwise, view to output shaft Fuel mixture :
Mixture (RON) Mixture 1:80-100 with BLUEMAX 2-stroke-oil, fuel min. 95 octane (other brands: 1:50, 2-stroke-oil, fuel min. 95 octane )
Delivery is usually 8 weeks on Hirth Engines not held in stock, smaller items have a much shorter lead time