Painting transmission casing.....does it effect heat transfer much?
Turbo Mini Forums

Hi chaps

Once my block is back i will be rebuilding my engine and i want to paint the transmission casing and clutch housing in the old school grey colour. I know that the paint will effect the heat transfer through the casing and hence restrict the cooling of the oil very slightly but how much of a difference does it actually make? Is it a bad idea? I already run an oil cooler but need all the help i can get in keeping temps down. Also whats the best way to key the housings prior to painting?
Cheers
Andy

it will make no diffrence for our applications

use red oxide for an under coat cheap as chips and does a nice job ...use 2 coats of you chosen paint 48 hours between coats

Paint it black. That'll help transfer!

Nice one chaps i will get painting the gearbox housings tonight then.
Cheers
Andy

Matt black is best at heat transfer.

Believe it or not any shiney surface will reflect heat back into the gearbox.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Here's one I did earlier (as they say on Blue Peter). Actually yesterday and today...

I used 2K etch primer.
1- good because it sticks best of anything to aluminium.
2 - bad because,
(a) you have to have the right protective equipment to spray anything 2K
(b) the earlier products (I'm using up some old stuff) are close to "GREEN" in colour. Fortunately the newer 2K etch is "chromate free" so doesn't have that yellow/GREEN colour.

However,

The black covers it up nicely.

Engine of course will be RED.

Schrödinger's cat - so which one am I ???

do you use red oxide paint for an undercoat on the block as well? in the past i've just used the high temp engine paint and had no problems. would i get a better finish using the red oxide first?

100% BMW Free

YES red oxide first

dont wast your money on fancy engin paint ,,, its not needed!

2 coats of normal golss of your choice will do after the red oxide and makes a fabola job

here my block done with semi gloss black

One coat primer one coat top coat. no need for the extra weight of extra layers of paint