Topic: how to get an even finish on my engine block

[75 super sport]

I did a little polishing with a buffer wheel, but now I have a very uneven finish. Just curious as to any tricks to get an even finish? Thanks in advance

[Whaleman]

Your going to polish out the whole engine cases? Dan

[75 super sport]

That's the plan. There was a lot of tarnish, so I was just trying to get a good finish out of it

[Retro Rocket]

A trick i used to get good gloss on an engine, especially if its cool or cold when you paint it, get a small fan forced heater, sit it near the engine and leave it on for as long as it takes to heat the engine, move it around to get the heat all over, then paint, you shouldn't ever have to polish a painted engine...

[Whaleman]

I don't think I have ever seen the cases of a CB750 all polished bright. Are you going to try to polish the cylinders and head also? Dan

[NobleHops]

You may well frustrate yourself trying to polish an assembled engine. Let me respectfully suggest you try red or grey scotch brite and a liberal spray of WD40, then use that to refresh the finish. That will look like satin, is much faster and easier to do. Maybe polish just the side cases?

You're likely dealing with old clear coat that has yellowed too. If so then you're best off stripping that chemically before going to abrasives.

[NobleHops]

P.S. Honda painted quite a lot of their engines, in case you weren't sure what you're seeing.

[75 super sport]

Thanks a ton for your time to explain the whole process to me! The head and cylinder are off, the old coating and all grease are removed. I used a medium abravise buffing wheel and it looks well, there are just a lot of sanding marks. I think if I take a very fine sand paper or scothbrite pad as you said above it will help tremendously. To be honest I kind of like the look of the uneven appearance. But I will try some fine sandpaper and polishing compound and post some pics. Thanks again

[jamesbekman]

Using a brass wire wheel on a drill works good as your first step.

[NobleHops]

Using a brass wire wheel on a drill works good as your first step.

I don't mean to be contrary for sport James, but I don't agree. I made that mistake when I was doing my 400, and most of the "brass" wire wheels are in fact brass coated steel. The ones that ARE all brass fall apart instantly.

It is all-too-easy to put deep scratches in soft aluminum with rotary brushes as I learned, and then you created more, harder work to remediate them. 

What's being left unsaid is blasting. If the engine is apart, they a homemade or Harbor Freight soda blaster will do a dandy job of cleaning and removing clearcoat, followed by hand abrasives and polish.

I'm in the camp of NEVER blasting with anything harder than baking soda on an engine that isn't totally disassembled, and even then, I have seen glass beads come to grief on an engine that was disassembled. But that's a whole 'nuther line of discussion.

[Jerry Rxman Griffin aka MuthaF'er]

blasting cabinet and paint.