Modellmaschinenbau
Armin de Vries

VT 84 4B  Production discontinued!

 

My 4-cylinder four-stroke boxer engine with 84cc uses tried and tested components such as pistons and liners from the V42; the pistons have compression and oil scraper rings, just like a "big" engine.
The B 84 is equipped with a one-piece, hardened crankshaft, which is solidly mounted in a torsion-resistant crankcase: Vibration forces and pre-programmed weak points are thus minimised. -
This engine does not have individual heads like the V42; it is equipped with so-called "banks" for 2 cylinders each. - This special feature is not a "designer quirk", but a design necessity with decisive thermal advantages:
A thermal bridge is built up via the twin heads when the engine is in operation, which reliably prevents the rear cylinders from overheating due to the design, even under unfavourable operating conditions, because the energy is absorbed by the front, colder cylinder parts.

Like the V42, this engine is also operated with normal petrol without the addition of oil thanks to its autonomous lubrication system:
This is made possible by a pressurised circulating lubrication system with a gear pump and various channels in the block; in this way, the required lubrication is not only generated by "centrifugal oil", but also a stable oil pressure is built up that is independent of the engine's flight attitude: The B 84 is therefore fully suitable for aerobatics!
The motor mount supplied is specially designed for this motor and enables precise, safe and simple installation on the motor bulkhead.
As with the V42, the starting behaviour of the B 84 is unproblematic thanks to an electronic Müller ignition with integrated, speed-dependent ignition timing adjustment; the ignition adjustment curve harmonises with the engine characteristics and releases solid torque even in the lower speed range. An electronic rev limiter protects the engine from damage caused by excessive revs.
The engine runs smoothly and evenly; additional vibration damping is not necessary.
All I can say about the engine's performance is that this four-cylinder boxer never really needs to flex its "muscles" to start and fly my 12 kg Flybaby...

Technical data:
Bore: 32.00 mm
stroke: 26.00 mm
Weight: 3100 g
Fuel: Normal unleaded
Ignition: Müller 6V with mc ignition advance
Power: 5800 rpm with 26 "X12 prop.
Engine with ignition and engine mount 2680,00 €