Originally Posted by
beardy
Forgive me if I misunderstood, but I thought that this could not be proven. I thought that the paper trail was incomplete for work undertaken.
The Vigilant engine is a Grob adaptation of the VW type 4 flat four air cooled motor, similar to that as used by Limbach and offered in 2.4 ltr form.
Grob needed more power and adapted the engine (bore increase to 2.5 ltr)
As most motor gliders use single ignition the standard heads can be used so parts costs are economical.
Under the LAA (the masters of VW engine use) engines can be reworked and OH under their inspector system which is both tech competent and very economical. This is because the engines are not used commercially (public transport). Every component is available for the Type 4 motor and indeed over the years a whole industry has developed supplying quality parts (including new high spec forged cranks).
When you add the long history of VW aero use and the tech expertise of the LAA there was a very cogent case for the current VIG engine to carry on in civ use.
Remember the VIG engine has no gearbox (unlike the Rotax) so it is a very simple unit that uses standard components for its main parts. The cost saving here are substantial and so is the reliability of the basic block and crank. Sorry another bleak, doom laden post from the west. But stating the facts !!!!
Anyone not familiar with the LAA (former PFA) system would be amazed at the level of expertise within that organisation, and its contribution to 'Flight' for anyone is considerable.