Cleaning/painting engine cases?

[Useful Idiot]

Mine are long over due for attention. I have some aluminum paint that I used on my forks and they turned out great, so I'm thinking about using it on the motor as well.

I thought about sanding, it's gotta hecka oxidation all over it. What's the proper way to sand a engine? Or if anybody has a link, that'd be great.

Thanks!

 

[matt365]

I'd just sand it with some 320 grit to remove anything loose, then wipe it down with acetone or thinner. Then coat it with engine paint.

 

[MBS]

I am not sure I would use acetone or thinner, this might turn any gaskets you have into bubble gum, unless of course you have the engine apart and plan to paint it before reassembly. The best way I found was to start with a degreaser and a brush to clean any dirt and grease from the fins. Then I would be sure to use some compressed air to clear out any ports, nooks or crannies that might have left over crud in them. You don't want to seal in any grime with paint. You can use a steel or brass brush to loosen any hard to reach debris. Then give her a couple coats of heat paint. That's my 2 cents. -MBS

I'd just sand it with some 320 grit to remove anything loose, then wipe it down with acetone or thinner. Then coat it with engine paint.

 

[Tim]

Of course the best way is to take the engine apart, split the cases and blast them clean. Then paint with high temp engine paint and cure in the oven while you're baking cookies.

You might get away with masking things off and then blasting the engine with glass beads to clean it completely. Of course this is serious business and you'd need to have access to a powerful compressor, glass bead, blasting gun and ideally a cabinet/blasting room.

 

[Useful Idiot]

Going to do it with the engine together.

Does it need primer or can you shoot the paint straight on?

Do I need to scuff the metal so the primer will bite in?

I've got a heat gun I was going to use to cook it in until I can fire it up.

 

[TonUpSoldier]

What kind of paint are you using? Im sure you realize that any regular paint would be cooked off in short order, and are using high temp paint. If you havent selected paint yet, i would recommend PJ1 (or VHT, i hear its the same stuff, made by the same company, just rebadged) From what ive seen, it works fantastic, much better than ceramic based paint that chips when dinged. It takes either baking like you said, or a couple of rides at normal riding temp, to cure. Untill it cures however its kinda stinky. The black looks especially good, but im sure the silver would look just as good.

As far as cleaning goes, if you're not media blasting, i would use a few bottle brushes and brass wire brushes on the motor, along with some SimpleGreen undiluted, works well. Wipe down after with alchohol to remove any left over oils, and you should be ready to go. SHouldnt need to rough it up with anything larger than 400 grit.

 

[buzz286]

I purshased a race bike last year,it had been painted(and raced) for the last 10 years with briggs and stratton paint(dark silver)and none of it has blistered off in that time,,it's nothing more than emanel paint...tremclad will give the same results

 

[Useful Idiot]

yea, I'm picking up the paint tonight and prepping. Thanks for the help guys, I'll post before and after's when it's finished.

 

[Useful Idiot]

I've heard that painting air cooled engine will make them run hot. You guys ever run into this?

 

[MBS]

I have been painting motorcycle engines with high temp paints for years, never had a problem. I don't think it will affect engine temp at all. Engines from most manufacturers come with a clear coat and some times a silver paint on the cases - so repainting the engine should not be an issue. Just my 2 cents. -MBS

 

[beardking]

To tack onto an already existing thread, anyone have any experience/tips with painting an engine while still in the frame? My Nighthawk runs quite nicely, but the paint on the engine (well, all of it really) leaves a bit to be desired. It's all still there, it's just faded. I have been considering the daunting task of taping the ever living crap out of the engine and getting some PJ1 and going to town on it.

 

[MBS]

The only suggestion I can make in painting an engine still in the frame is to use some old garden hose. Cut sections of the garden hose to the desired length and slice vertically down one side. Use these to slip onto the frame and secure them in place with masking tape. This will reduce the hassle of masking, at least a little. Aside from removing the tank and other parts that are easily accessible, along with masking parts and ports on the engine you don't want painted, thats is all the advise I have. To do it right and get even coverage, it would be best to bite the bullet and remove the engine. If your going with black for a color, paint the frame and engine together, that will also minimize masking. I use masking paper and news paper to cover large areas. -MBS