oaros

Got a replacement oil cooler to replace the slightly bent one.

New one isn't painted black as original. Does it matter? Is paint needed - or the aluminium fine on its own?

Oliver

davek9

I would shoot it a Black semi Gloss eng paint, it will keep it from oxing and it will blend in.

oaros

Done - thanks; makes sense re the cooling effect.

EDIT:
Hmmm 1:1 now

tilac999

I agree, but a very light coat.

When done, go for a nice drive to the Trout and enjoy a pint. Or, the Perch, Turf Tavern, or Victoria Arms in my old neighborhood of Old Marston.

Cheers!

oaros

Trout and Victoria Arms - good places for a pint and a meal this time of year.

neilh

^^^^
+1 on that , my old favorite haunts as well....
Cheers,

Tails

Oliver,
Paint it with a flat black engine paint. When I purchase my car I cleaned the A/C condenser and the oil cooler fins and painted them with the flat black engine paint, no problems with A/C or oil cooler.
Tails 1990 928S4 Auto

Ducman82

i like the alum in its natural state....... more cooling that way too.

Rob Edwards

Curious, both my GT and GTS had silver unpainted oil coolers. I'd have thought that Porsche would have painted them (like the A/C condensor) if they thought they needed protection. But perhaps that's why both have leaked and been repaired....

jpitman2

Black will radiate more heat than silver, as long as the paint layer is not thick enough to act as an insulator. Thats 'radiate' - I suspect that most heat shedding here is conduction to the passing air flow, with radiation only relevant when stationery.
jp m83 Euro S AT 53k

Rob Edwards

Probably doesn't matter one bit, neither painted or unpainted is any good when sitting in traffic, the oil cooler doesn't do jack in that instance.

GregBBRD

Flat black radiates heat. Gloss black actually retains heat....and Rob just hit the nail directly on the head. These coolers absolutely suck in traffic...I can never figure out why the GT and GTS models had such severe cam wear....

If I really need to, I can find and direct you to some references for the paint thing...

Mike Simard

There was a Corvair engine book that talked about that. I was blown away by that and have always wondered how real it is.
Since the black promotes infrared radiation heat transfer, as we know by leaving something black out in the sun, it could even help when there is no air movement at all for the conductive heat transfer the radiator was sdesigned for. The radiator in still air would be radiating infrared energy, the question for me is just how much heat is being shed that way versus conduction with air or water.

nc_growler

Just got my reconditioned oil cooler from Roger - flat black. Looks just like the original...

svpmx83

A single light coat of flat black engine paint on the fins
Two or three light coats on the end tanks/welds and top/bottom plates for corrosion protection