Bad idea to powdercoat rotor housings?
 

I heard from someone (who is reputable) that powdercoating rotor housings can cause warpage and thus cause a coolant seal failure. Is this true? I know of a few people who have powdercoated their housings with no ill effects. I'd like to have my housings powdercoated but if it really is going to cause problems, then I'll just go with high temp engine paint.

i think you need heat AND pressure to warp the housing--unless it's done incorrectly. talk to raspy from team fc. he does them with good results.

Problem with powder coating is that you have to bake the powder in an oven at about 450 degrees for it to set for about 3 minutes. Its possible that warpage could occur on a rotor housing exposed to these temps if it is placed in the oven all by itself.

However, if you were to bolt up the rotor housings to junk Irons, or powdercoat your Irons at the same time (if you want a 1-color motor), and put all the tension bolts in and torque them down, the heat should never reach the inside of the block because of the short dwell time and as long as the assembly was allowed to cool properly before dissassembly, there should be no problem with warpage whatsoever.

Most powdercoaters use a hanging conveyor through their ovens, so, it might be a bit dificult to find someone to do an entire block!

i've talked to 3 or 4 guys with powdercoated housings that didn't have any problems with them.

i've never talked to a guy who had them powdercoated and did have a problem.

I dont see how 450 degrees F could damage the rotor housings.

My guy that does powder coating for NASA & Lockheed does a slow cure process at 350F

sometimes he'll up it to 400F on some powder coats.

I have done a few rotor housings and have had ZERO problems.

The metal is too thick to warp at those temps.

Just look at the wheels that I have done powder coated.

I have powder coated doors, sunroofs, and fenders with no ill-effect.

My alluminum hood had a slight warpage.

I've seen several housing done that way, and No one has ever said anything ill about it.

Thanks for the insight everyone. Will definitely get my housings powdercoated then with some junk irons so it doesn't touch any parts of the oven pan.

Got anyone in mind for the powder coat?

;)

how much you charge batman?

it depends, but the most common thing that I do are wheels.

Standard colors like my gloss black rims are $250 for the set. Includes the prep work and 2 layers of powder coat.

then add $80 for round trip shipping

I've dealt with powdercoating the housings, and have had bad experience with them, the rotor housings warped, then allowing coolant into the combustion chambers. 400+ degrees for 20 minutes or so is bad. 230 is considered overheating for an engine..just paint them...or take the risk.
ERic.

I have a pair of rotor housings that were warped when the engine overheated to 280+ for a few minutes. I measured them and they are just out of Mazda spec. There is a risk with powder coating if it is going to be heated to 450 imo.

that's a good point.

Hmmm... If you were powdercoating the rotor housings while the engine was running that might be a problem. But what you fail to realize is that while the water temperature will regularly reach 190 degrees during normal operation, the combustion chamber temperatures regularly reach 2000 degrees (higher on turbo engines) during normal operation. When an overheating engines water temp reaches 280, you have localized boiling. Steam doesnt transfer heat as well as liquid water. The heat sink isnt there anymore, so internal componets will get damaged if they see 2500 degrees. The water running through the coolant passages protects the engine from those high temperatures. Have you ever taken a plastic bottle full of water and placed it in a fire? The water will sit and boil for hours before it all evaporates. Even though the plastic melts at 200 degrees, its able to sit in 1100 degree fire without melting as long as the water is keeping it cool.