• Valach by Fiala VM 420 R5
  • Valach by Fiala VM 420 R5
  • Valach by Fiala VM 420 R5
  • Valach by Fiala VM 420 R5
  • Valach by Fiala VM 420 R5
  • Valach by Fiala VM 420 R5

Valach by Fiala VM 420 R5

Please contact for possibly lower shipping rates outside the US. 

Valach by Fiala 420cc R5 radial gas 4stroke engine with electronic ignition and electric fuel pump incuded - This motor has been designed from the ground up for fuel pump usage, the Fiala/APS fuel pump is already included (US$250 value).


  • Cylinder:  5
  • Displacement:  420 cc
  • Output:  ca. 25 hp
  • Bore:  47 mm
  • Stroke:  48.5 mm
  • Diameter:  425 mm
  • Length from engine mount to prop hub:  255 mm
  • Weight:  11.8 kg
  • Ignition voltage range:  6 - 9 V
  • Idle RPM:  800
  • Max RPM:  4500


Click for Dimensions


If my Valach Ignition has a second JR cable:

It offers you a kills switch functionality. Is for ON / OFF switching your ignition.

Hook that up to your receiver, set up a negative/positive mix and you are set to go.

Recommended prop: Please see that you run Valach engines on Fiala props.

Fiala owns and makes Valach engines, the development of the engines goes hand in hand with the development of their propellers, these is truly the only make that has a custom prop in mind.

Props are not simply paddles that drive an engine forward, they are sophisticated designs with well thought-out airfoils.

In this case engine are propeller are matched.

Dr. G's recommendation


Fiala 40 x 20 Fiala Propellers - 2 Blade – Vogelsang Aeroscale






Valach motors were designed with Fiala props in mind. Should you want to run the  shown pitch and diameter recommendations you WILL need to run a Fiala prop. Should you want to run props of a different brand you will most likely have to drop 2 in pitch due to Fiala's unique airfoil choice. Other brands plain run at a higher drag rate.


Very convenient to have as the Valach does not come with preinstalled throttle and choke horn: