Iwant to cut some wholes in my F27 to allow the hot air out anyone know the potimum place to put them and size (round) cheers Keith

put then at the back of the engine bay where you want to hot air to come out, a picture of your bonnet might help us give you better ideas

This thread might help...
Link

See my post in the above thread.

The issue with vents on top at the back is if something lets go under the bonnet, smoke, steam etc in the face

Here's what I've done at the trailing edge:


More vents!

...and directly above the exhaust headers:


More vents

John.

from linky above

Joe
Rescued attachment fitted mesh.jpg

Potimum.... lets see now....

Its a littel known fact, but as you ask - Plant enzymes have a lower potimum temperature than humans.