Yep. Water cooled heads.

SCAT used to build brand new water cooled heads for air cooled VW engines.

Could be that Rotax picked up the design and technology.

John Rodgers
88 GL Driver

George Thorburn wrote:
>>> Used in the Predator pilotless drone, about 160 hp, never installed.
>>>
> http://www.pilotmarket.com/products/Aircraft_Engines_for_Sale/listing-1524-11496-59789192.html
>
> What are all the holes about?  I can see the intake and exhaust ports but what are the other holes in the heads and near the front and back of the motor for?  Are the heads liquid cooled?
>
> Enquiring minds need to know.
> George,
> 85' Westfalia
>
>
>