TOPIC:

I'm thinking about painting an assembled engine with Gun Kote. The problem is gun kote needs to be baked at 350 degrees for one hour. How bad would it be to subject an engine to this? Im wondering about the seals and stuff, as this is way over the operating temp. I can use some other paint, but IMO Gun Kote is the best engine paint, so id like to use that if i could.

I will throw in my .02.....

The engine components would be fine I think, but the seals and gaskets will be damaged IMHO. Powdercoat is usually only 50 F higher baking temp, and you have to pull all seals, plastics, and gaskets prior to that, so.... If you are going to do Gun Kote, I would disassemble the engine down to the parts you are coating.

I would also contact Gun Kote to see if they have an alternative baking schedule. i.e lower temp for longer time....

FWIW,
Cory

You don't need 350F. 275F is enough, you just need to extend the cure time. The engine will get this hot while riding on a hot summer day so the paint will auto-cure by itself while riding. I think you just need enough cure to improve the surface handling toughness because the coating scratches/chips/smudges easily before cure. Once the engine is together the engine heat while riding will finish the job.

I recently used Gun Kote on my 750 wheels and brake calipers. You need to sandblast first according to the instructions, so that's what I did. I found the preheat unnecessary. The paint stuck just fine and didn't tend to run or anything. Only issue I faced is that the "satin" is too glossy. I'd get the flat if you want a satin or lower gloss finish.

I agree with the cooler 250-275 degree's ........ I did my valve cover, carb tops etc and was worried about warpage so I went less and stripper won't even touch it still ...... takes the paint off no problem up to it but doesn't do a thing once it get to the coat.

Just got some heat number about two weeks ago. Used a handheld laser thermometer.

I let bike idle at 1200 rpm for 10 to 15 mins with a goose of throttle now and then. It was a 50 degree day.

Cylinder Head: 306 deg f
Cylinder: 235 deg f
Header Down tube 4" from head: 575 deg f Kerker
Header Rear Collector: 200 deg f Kerker
Oil Cooler: 145 deg f

I would assume that on a 90+ day, the bike could get over 425 deg f. OLDMANROCK is a good source for this as he is in Arizona.

When I had to cook the header kote on my pipes, I used a heat gun. Worked very well.

I'm gonna soda blast the entire engine first, be cause the PO painted the engine without cleaning off the road grime. the paint is literally coming off in sheets. Depending on how it looks after that i will decide to paint or not. At the least I will probably do the cylinders in black. thanks for the responses guys.