For their Druine Turbulent aircraft Rollason Aircraft & Engines Ltd. situated at Redhill aerodrome (Surrey), modified and adapted Volkswagen car engines. This was in the late 1950's.

-Initially it was based on the French Ardem 4CO2 that already was a VW conversion.

-First they modified the 30 HP Ardem 4CO2-2, changing carburetors and adding heating, varying compressions or in the case of the RTW Mod, eliminating the chain that drove the magneto and connecting it directly.

“Rollason engine on a Turbulent”

-Of this 30 HP, 1200 cc engine another modification was made, enlarging cylinders and going to 1300 cc giving 40 HP, FH modification, shown in the picture.

-But there were two basic displacements in the normal Rollason offers, the 1,500 cc and the 1,600 cc.

-The 1,500 cc were offered as the 45 HP, low compression (7.8:1), Mk4 models.

-The Mk5 version that gave 55 HP at 3,300 rpm was a high compression (8.5: 1) engine.

-The Mk X gave 45 HP with 1,500 cc, and it was officially approved by the CAA.

-Finally the Mk XI, with 1,600 cc giving 55 HP at 3,300 rpm.

From Appendix 12: English manufacturer of Ardem engines, based on automotive Volkswagens, based on the 1,200, 1,300, 1,500, and 1,600 cc.

-Taken from an ad in an English magazine, we show a photo of the Ardem Mk-X.

“Ardem Mk-X on a Turbulent”