Will a vented headlight cover be worth it to reduce engine temperature or am i better of with a stock cover?

 

No, not really. It was originally suppose to feed ambient air to open intakes that were popular back in the day. But if you look at it when installed, air passage to the engine bay is actually blocked by that upper frame/support of the headlight assembly....rendering it useless. It may look cool, but that's all it's worth. It will do nothing for "engine temperature", and any difference in venting under-hood heat wouldn't be measurable. It's just as likely to attract snickers.

 

Might still go for the vented cover just for the Looks then haha Thanks for the useful info

 

The engine is water-cooled, not air-cooled. A headlight vent will not significantly help cooling unless it feeds an auxiliary radiator, or unless you machine cooling vents into the engine "block". As stated above, the headlight vents are usually intended for engine air inlets. Products that reduce "underhood temperatures" are one of the biggest scams out there. If you want to cool the engine, then use a good radiator and proper ducting.

Air-cooled rotary engines have cooling fins like this:

 

are air cooled rotarys used in what situation airplanes?

 

Mostly in airplanes and motorcycles.

 

I bet they rev pretty high don't they?

 

The O.S. Max model airplane engine revs high, but so do the model airplane piston engines. As far as I know, the motorcycle/snowmobile and airplane engines operate in a similar rpm range as the automotive engines.

 

Do they still go brap brap brap? haha