I watch a fair amount of European hill climb racing, or Berg Cup in Germany and other places like Switzerland and Austria and have noticed a recent (last few years maybe) trend of drivers in the Group H small classes (old style cars like Polo, Golf, Kadett, Nova etc maybe 1600 or lower), using performance motorcycle cylinder heads on their cars.
I am presuming this is to allow better breathing and perhaps also the use of the entire bike injection system rather than a bespoke setup using a set of carbs or a new injection system. Obviously this breathing suits smaller, revvy engines that match a bike engine. And then also the bottom end can be further lightened and built to match this increased rev range.
I have never seen this anywhere else in motorsport much?
I am aware that a lot of guys use Minichberger to do this, a specialised VW tuner really, but also involved in other cars.
How on earth do they get the heads to match the blocks of the car engines? They must be far narrower and more tiny compared to a car block? A bike engine is usually very narrow and very thin in comparison? Plus a lot of bikes run camchains internally I think? Must be a hell of an undertaking.
Does anyone know any other motorsport where engines use a mixture of bike and car tech together?