Honda engines; painted? raw aluminum? clear coat? restoring the original look

[Garage_guy_chris]

Hey guys have a question about my 71 cb450 but i figure this applies to most honda's of the late 60's early 70's. I like the look of the engine as it sits (except for the dirt) and id like to maintain the look of the cases, that sand cast texture and colour.

Only problem has been i cant quite figure out whats been done to the engine at the factory, the crankcases look to have the clear coat, but its all yellowing, hazy and flaking off. then the cylinders almost look like they have a flat silver paint on them?? then the cylinder head i can't tell at all, the head covers have been clear coated but the actual head casting I cant tell. So if anyone knows what they did at the factory please share.

I have already cleaned this engine up about as good as it can be done with cleaners and brushes. The next step is to media blast but i don't want to change the original sand cast texture, anybody have a recommendation on media and or an alternate method to get 40yr old gunk off the engine in almost impossible to reach places?

Lastly what engine specific paints have people had trouble with and what paints have worked well?

 

[VonYinzer]

Re: Honda engines; painted? raw aluminum? clear coat? restoring the original loo

Use baking soda on the alum. It will take all the olg crap off and leave the metal as is. All they used was a clear coat, though its not a real high gloss like most. Any decent engine enamel will work fine if you follow the directions. Whatever ya do, dont cake the paint/clear on. Light coats. Ive used the Duplicolor brand engine paint with great results. If you have a way to "bake" the paint on the motor, even better.

 

[swan]

Use the search button. There are dozens of threads on this forum for painting Honda crankcases.

 

[bikeboy]

The best results I have seen are parts the have been vapor-blasted. Brings the metal back to new without damaging the surface. Most of the engine covers (clutch/timing/alt etc) do have a clear coat from the factory. They are sort of between a polished and brushed finish? I think they tumble them? I've used VHT paint before with great results, and as von says, if you can get some heat into them, the paint will last longer.

Show us some pics

ian