External of Polishing Parts?

[korbendallas68]

I think I remember reading that the reason for the textured surface of the aluminum parts (heads ect...) is to dissipate the heat better through more surface area? And that polishing them will actually lower the surface area. Just curious really.

The reason I ask is cause I was thinking of polishing the aluminum parts to a nice reflective shine.

[sharkey]

the textured surface is the casting process. technicaly it does dicipate heat, but its not the primary reason for the textured surface. polishing isnt going to cause any harm.

[korbendallas68]

Ah cool. Thanks. I figured it was just a part of how they were casted.

[korbendallas68]

Anyone have any tips on polishing the rough texture?

[sharkey]

you need to sand it down, start with 220 and move up to 1200, then move to polishing compound

[korbendallas68]

Wish I still had my dremel drill, seems it could help a lot in those tight areas.

[geoffinbc]

A Dremel is too weak. Your going to need a die grinder or a heavy duty rotary tool with an 1/4" shank.

Results of good polishing

[ForcedFirebird]

A Dremel is too weak. Your going to need a die grinder or a heavy duty rotary tool with an 1/4" shank.

RotoZip works good

[korbendallas68]

Results of good polishing

Now that is exactly what I was thinking. and possibly doing the LIM, water pump hosing, ect...

[Monzsta]

AAAGHHH! RED LOOM HELL!! lol! j/k

[3100 MPFI]

I do the polishing to just give it a little something extra. My old 2.8 plenum, I had it reflective. I have a pic of it now, but it needs to be cleaned up. It has not been used in over 3 years, so it is not as shiney as it is with the polish on it.

Here is a pic of my old 2.8 plenum. You can clearly see my old cellphone. I might clean it up this weekend and hang it on my wall.

Here it was in the car:


and here it is now:


Here is the 3100 intake on my car now. I only polished the numbers and letters on this one. I wanted something that will grab you, but not blind you.


When I did mine, I started out by using a flapper wheel on a drill until I had it smooth (well, that is how I did it on the 2.8 plenum). Once it was smooth, I wetsanded it starting with 1200 grit. I then went up to 2000 grit gradually.

Once I did the 2000, I then used a polishing compound/cleaner called cat piss. That was not really it's name, but that is what it SMELLED like. It had a blue lable, and was blue itself.

I might try to get some later today and use it on my old 2.8 plenum.

[kflo 93 gt]

I really like the jitterbug pneumatic palm sander, start at 80 grit and work up like its a full time job. Once you get into the higher grits put polish directly on the part and keep using the sander - that really drives home the results. Keep stepping up the grits and adding polish for the win. However, I'm glad I don't have all of that anymore, it's too much to keep up with the shitty splash guards our cars have. Weekly polishings get old quick.

this is for my polished pieces nowadays.

[IsaacHayes]

A polished surface actually doesn't radiate heat well at all. A mat black finish will radiate heat quicker. You can polish aluminum, and take another identical piece and paint it flat black, put a heat source on it like a power LED ran at identical watts, and then measure the temp inside of each piece and the black will be cooler.

Does this matter for an engine? Probably not much. It will keep your underhood temps lower with polished stuff! hehhe

[korbendallas68]

Thanks for the tips guys.

I've always like the flat-black look too. But the only way I'd do that I think is to have them powder-coated? From what I've seem, spray paint, doesn't hold up well, or coat the parts evenly enough.

[IsaacHayes]

Surface prep and the right kind of paint helps. That and then not laying your tools on the plenum when working on the car helps keep it from chipping off. I used Semi-gloss for my engine. You can make it less shiny by keeping the distance with the paint and not putting it on too thick where it all melts and turns glossy. That way some of the particles dry mid-air as they land and leaves a flatter surface. Get too close and it all dissolves into a shiny surface.