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Designed and manufactured

 in the UK


Wren 50 Helicopter

Wren 50 Turbo Prop

 Max. Power Output

6.8HP / 5Kw @ 190,000 rpm


1480gms / 3lbs 4oz

 Overall size centre section

305mm x 75mm / 12" x 3"

 Ancillaries weight (inc battery):

  280g / 10oz


  As for OS91 heli engine

 Output Shaft Size  

3/8" dia + 5/16" UNF (as for OS91H)

 Gearbox output shaft rpm range

4,000 to 15,000 rpm

 Fuel Consumption @ max thrust:

176ml per min / 5.8oz per min

 Max. Torque  

4Nm / 2.9 ft Lbs @ 13,500 rpm

 Max. Power Output  

7.5HP / 5.6Kw @ 195,000 rpm


1680g / 3lbs 11oz

 Overall size centre section  

326mm x 86mm / 12.8" x 3.4"

 Ancillaries weight (inc battery)

280g / 10oz

 Mounting  Hole dia

85mm / 3.4", 6 x M3 screws

 Propeller rpm range

1,100 to 9,000 rpm

 Fuel Consumption @ max thrust  

176ml per minute / 5.8oz per minute

Propeller size range  

17" x 12" - 28" x 10" (2 or 3 blade)

Recommended Set-up

6.400 rpm on Metz 22" x 13" 3-blade prop

WARNING - It is most important that there must always be some load on the output shaft as  the 2nd stage turbine will be running unrestrained and may easily speed up beyond it's safe running speed, even when the gas generator is running at only a modest rpm. The unit should NEVER be run without a suitable load attached.


To place an order please email your order to us at sales@wrenpowersystems.com

You will be contacted by Wren to verify your engine choice, delivery date and shipping requirements.

   A deposit of 40% is taken on engine orders - the remainder being due immediately before delivery.



    The world's smallest production 2-shaft helicopter & turbo prop

i-kero start system

Small physical size – extremely short length enhances install options    

Integral high quality FOD screen and starter mounting    

Solid stainless steel bearing carrier system   

 High precision ceramic bearings    

Inconel combustion chamber for long service life    

High quality Anodised case for excellent service life and superb finish    

Fadec ECU    

50 hour service interval

 WREN 50 TURBO PROP - £3300 + VAT

WREN 50 HELI - £2950 + VAT