Valach Engines

VM 140 B2-FS

The Valach VM 140 B2-FS has the same well proven Nickel-Silicon plated cylinders and the cylinder heads as the VM 120 B2-4T on a new CNC milled crankcase. The longer stroke of the crankshaft taken from the VM 170 B2-4T increases the displacement to 140cc.

The VM 140B2-FS is also available with a starter. With the current version of the VM 140B2-FS the starter can be retrofitted anytime.

  • Nickel-Silicon plated cylinder surfaces
  • CNC milled crankcase
  • Completely encapsulated valve train
  • Sensational smooth running and high torque
  • Spontaneous throttle response and smooth midrange transition
  • Extremely low vibration throughout the RPM range because of the four stroke principle
  • Honda valves and valve seats
  • Walbro carburetor
  • Valach microprocessor controlled ignition with auto advance and retard
  • An ignition integrated voltage converter allows the use of two LiPo cells
  • VM-engines are now being produced with state of the art machines and methods
  • Rapid spares delivery and repair service from Germany by Toni Clark practical scale GmbH

Due to being a four stroke, the low vibration is nothing but sensational, and torque is really high. The response to the throttle being opened is so smooth without the slightest attempt to surge, making the Valach VM 140 B2-FS absolutely ideal for your big aerobatic model.

Being a four stroke with a large capacity, it produces a very realistic full-size aircraft sound. With a relatively small silencer the sound level is very low, rather like a small saloon car. The silencers and headers for the VM 120 B2-4T can also be used for the VM 140 B2-FS.

The Valach VM 140 B2-FS is a four stroke OHV engine running on petrol/oil mixture. We have tried many oils and recommend Valvoline SynPower 2T oil. Our BEL-RAY H1R, although excellent for two strokes, is not ideal for four strokes, as it burns very well without deposit, therefore not much gets past the piston. With Valvoline Synpower 2T a lot more oil gets through to the crankcase. In Germany we recommend Aral Ultimate 102, as the smell is not so penetrating, it can be stored without deteriorating and it does not contain ethanol! If in your country petrol does not contain any ethanol, you can use any brand you like.

The fuel consumption is only approximately 50% compared to that of a two-stroke engine with the same displacement.

Valves and their seats are manufactured by Honda, ensuring a very high quality. The totally enclosed valve train reduces sound, as well as ensuring the rocker arms are well lubricated.

The processor controlled ignition allows easy starting and a exceptionally smooth running in all throttle settings.

The Valach engines VM 140 B2-FS looks just like an original aero engine, only smaller, it runs smoothly like an original aero engine and above all it sounds like an original aero engine. The legendary perfectionist Henry Royce of Rolls Royce always insisted that an engineering construction to be right must look right. I defy anyone to tell me the Valach Twin does not look right.

Due to the rather pungent smell of normal grades of petrol and the ethanol content, we recommend using Aral Ultimate 102 in conjunction with the synthetic two stroke oil Valvoline SynPower 2T.



140 cc


47 mm


40 mm


330 mm

Length from engine mount to prop hub

186 mm

Weight with prop washer and prop bolts

4,005 g

with Starter 4,485 g

Weight complete with ignition, prop washer and prop bolts

4,183 g

with starter 4,663 g

Ignition voltage range

4.8 - 9 V

Idle RPM

800 rpm


6,200 rpm

Fiala Prop 2-blade:


5,260 1/min
5,100 1/min
4,650 1/min
4,550 1/min

Static thrust:
with Fiala 32x12"
with Fiala 34x12"

24.0 kp
24.5 kp

Recommended static RPM range



1:30 - 1:40

Fuel: Valvoline SynPower 2T / Aral Ultimate 102

VM 140 B2-F2

More Information

We have measured the above RPM and static thrust when using this simple muffler. It is a 40 mm dia. stainless steel tube of 0.3 mm wall thickness; the exhaust pipe is 22×0.2 mm, 15 cm long. The muffler is “empty”, has only one chamber. It is fixed to the engine by the two headers only; this works because the muffler is very lightweight and the headers are short.

This Y-fitting makes it easy to remove the unwanted oil from the pressure tube of the carburetor. Loop-in the two “branches” into the pressure tube and extend the “trunk” about 6-12 cm to lead it to the lower side of the cowling. Place the Y-fitting underneath the carburetor and the surplus oil will be gathered into the “drainage tube” and can be dumped from time to time, without removing the cowling.

Attention: do not forget to close the tube securely with a plug!

Like on the VM 120 B2-4T, the valve train of the new VM 140 B2-FS is fully encapsulated, improving rocker arm lubrication and the valve train runs quieter. The crankcase is manufactured from solid aluminum.

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