Can you repaint a motorcycle engine? or will it cause it to over heat?

Question

it's a 1991 honda nighthawk 750 aircooled and it had some kind of buildup on it so i carefully used a dremel on it to get it off but it took off the fatory coat off the block so i'm not shure what to do I dont want it to rust on me.

Answer 1

I had a '76 750K Honda that someone had painted the engine black, I rode it for a couple of years and never had a problem with overheating.

Answer 2

Heat Resistant Engine Paint

Answer 3

Hi David,,,

Almost All the material on a bike engine is Alumium.
It wont rust,,,but it will corrode Badly and Quickly(relatively speaking)

I checked to see if a '91 was Black or Silver.
I found BOTH pictured as '91's.

The Black is just Paint.
Best,longest lasting BLACK Hi-Heat paint I've ever used
is:
Rustoleum BBQ Black #7778
It's Very High Temp,,,and sort of a Semi-Gloss,or "Satin" finish which is Black-Black without much grey sheen to it.
It matches Honda's original black engine color used during Your 750's era pretty close.
It adheres very well,,,cleans/washes Fair,,,and stuff doesnt seem to stick too badly to it.
Holds up very good to gasoline & oil being spilled on it.

I've always got good results and been satisfied with color/finish of it.

It AINT Perfect,,it's "just Spray Can Paint",,,but It's the best readily available stuff that's Cheap & Easy to DO,,,and maintain,,,and Touch-Up as needed.

It sprays on and dries almost "gummy" and engine heat eventually cures/hardens it

..............................................
SILVER,,,,,
Some Silver Engines are painted.

Color Match on those gets to be a nightmare.
Most are Clearcoated over the Silver,,,,which Changes the COLOR and the overall appearance.
ClearCoat on silver has an odd effect.
And Silver can be anything from "Greys to various aluminum shades,,,to "Bumper Chrome".

A Good Match has always been sorta trial & error for me.

Lots of Silver motors are simply polished then Clear Coated.
Best Hi Temp Clear I've found is:

VHT Motor Bright #SP29

It's a hi temp Urethane,and will stand about Twice an engines avg crankcase and valve cover/rocker box temps.
NOT very Good for Cylinders,,
and not good at all for Cyl Heads.

Even is engine is painted Silver then clear coated,,
VHT SP29 will give a decent match as a top coat over areas where paint is "missing" next to areas With paint.

It's CLEAR,,,so it covers NOTHING.
If a damaged paint area is splotchy,,,this does nothing to help the appearance.
BUT,,You can clean up that area,,,and it''ll blend the areas Somewhat acceptable.
Not too bad,really---depending upon the condition.

And in any case,,it Does seal & protect the bare metal,,,doesnt yellow from the heat like Lacquer does,,,and it stays on pretty well.

You get it back Very Close,,and acceptible without a bunch of effort or expense.

Good Luck

Answer 4

It may not make it over heat, but it will run hotter. Look at the fins on the jugs and heads, they're cast for a reason, for more surface area. Once you paint the rough surface, you take away some of the surface area that dissipates the heat. Look at some of the racers, diamond cut jugs, natural finish, there's a reason, the more it dissipates the heat.

And radiators are not painted black for heat transfer, paint is paint, unless you are trying to capture heat from the sun..... they're painted for aesthetics and to stop oxidation, who wants to have a radiator stand out in the front of their vehicle, other than a show car?

Answer 5

To repaint your engine you will need some form of heat-resistant paint, you should be able to get some from a Auto or BBQ store.

Answer 6

Repainting won't cause it to overheat but the engine heat may cause the paint to burn off. This job is best left to an experienced professional.

Answer 7

The auto stores or some paint stores sell high temp paint that is meant for using on engine parts bar b q etc...you could also call an auto body shop for advise.

Answer 8

Yes, you can.
No, it will not.
Tomcotexas has spelled out the details.
I agree with his choice of black paint.
It's what I used, and never had a heat related problem.
For contrast, I ran a file over the edges of the fins after the paint set.

Answer 9

the purely different reason i am going to upload is piston skirt length. Stroker pistons have the wrist pin hollow relocated decrease on the skirt, making the piston journey larger at TDC and decrease at BDC, in result, lengthening the stroke of the engine. The area results of it is with a shorter piston skirt length, the piston has a tendency to rock, or "SLAP" extra.

Answer 10

yes you can repaint an engine, but if you are that concerned, why use paint. look at using a ceramic coating like ones from jet hot http://www.jet-hot.com.au/.