Painting of cases and engine parts

TURBORS930 · 10-23-2007, 05:29 AM

Is it not a good idea to paint the case and other engine parts ie because of heat retention or simillar what are your views????

3.2 CAB · 01:02 PM

Hi, I will take a shot at it being no one else has replied so far. Like you stated, the heat retention is a view that I have seen here many times. Parts very well may "hold" temps longer if painted. But this has a couple of ?'s involved, if this is the case, why do people paint their brake calipers, you know how hot those things get. I have also seen the valve covers and other engine parts also painted or powder coated. If there was another 3.2 in my area, that had painted parts, I could see, (if the owner would let me) take temp readings with my hand held temp. gun, to see if there was really any difference in if the parts were painted or not. But if you think about it, almost every one of the American, iron engines are painted, the biggest part due to rust I would think, but on most of the alloy or aluminum engines or parts, most of the time they are left with the natural metal finish. So go figure???? I guess it is time to flip a coin!

Eagledriver · 10-27-2007, 06:52 PM

There is probably some heat retention from painting things like the case and housings. I don't think it is enough to cause problems. I wouldn't paint the cylinders or heads but I think the rest is fair game.

-Andy

TURBORS930 · 10-28-2007, 12:47 AM

thanks for the replies, i was not sure and i tend to agree that i dont think it will make much difference, we will see once it is finished

304065 · 10-28-2007, 05:48 PM

A word of caution . . . it's VERY hard to keep the coating from failing and flaking off-- high heat, vibration, oil, etc. All over aluminum or even worse, magnesium. The factory didn't paint anything. Also, it's a personal choice, but most people don't like the look of a painted case, this would tend to be off-putting to subsequent buyers (if a sale is in the future at all). That said there are those that do, look at Gigem75's recent thread.

MKEDF · MKEDF's Garage

Im rebuilding my engine, and have seen lots of pictures on this forum that have engines with nice paint jobs on valve covers, up and down...

The guy at the garage that is leading the rebuilt on my engine told me not to paint the lower case covers..

Because the lower cover is designed to get rid of heat efficiently, the forms on the cover help a lot on that..

But if painted, the heat will stay longer, causing leaking problems to come back...

911 engines are well known for leaking..

So You have a choice to make, paint and have heat issues or just clean your engine to look shiny..

MiCk...

hcoles · 10-30-2007, 08:40 AM

+1 for what John Cramer said

mb911 · mb911's Garage

I had my outer chain boxes done but nothing internal. The same with the valve covers. I would not go any further then that personally because of the possbility of excess sand etc left over from the prep process

911pcars · 11-01-2007, 12:34 AM

"Because the lower cover is designed to get rid of heat efficiently, the forms on the cover help a lot on that."

Maybe on an SC or later engine with only a cat on one side (with a heatshield too), but when the engine is running, earlier 911s with 2 out heat exchangers or later engines with SSIs radiate more heat into the lower valve covers than the valve covers will radiate to the surrounding air.

A law of physics: Heat travels from a hot area to a cooler area.

Sherwood