Best way to polish LIM & UIM on FD?
 

I want to polish my intake manifold but dont know what to use.
I tried searching already and cant really find any good tips.
Or would it be best to take to a shop and get it done professionally.
Any advice would help

For the LIM, I would suggest ceramic coating instead. There's a lot of heat down there so the ceramic coating will help reduce the amount of heat absorbed as well as looking good.

This is not my LIM, but a picture of what the coating can look like:

http://rx7tuner.com/images/Ceramic%20Lower.jpg

Nice pictures
I never thought about how much heat is produced in LIM especially if I am going with a single turbo setup.
Thanx for the info

Will powdercoating help at all with the heat?

Powercoating will do nothing for heat insulation. You need to do a ceramic coating or similar insulator to protect against heat soak from the surrounding exhaust manifold, and motor.

However, I would still highly suggest starting the polishing process as the ceramic coating still shows all the imperfections of the casting, i.e., parting lines, saw cuts, grind marks, core and sand porosity, etc. Start with 120 or 180 grit sandpaper and work it smooth, then go to 240, then go to 300, 400, 600, then ceramic coat it; it will look smooth from the sanding you've done but retain the flash and insulating properties of the ceramic coat which gets polished itself in a vibratory finishing bath using ceramic beads to get the glossy chrome-like finish you see in the above picture.

The above picture shows very well how someone didn't spend any time sanding the surface clean as you can see all the rough texture...that's what that's from, not sanding it smooth first.

how much was the coating

That's not my LIM (as I stated in the original message), but mine will be done in that way.

Talk to "DFW RX-7 Cook", they did that coating which is pictured above. I believe their prices range from $150-200 depending on the part.

As far as your UIM goes, just get some sand paper 80, 150, 220, 320, 400, 600, and get some polishing compound. Tripoli is good for aluminum. If you've got the time do it yourself..but it is a lot of time. Rob Robinette has a write up on his www.robrobinette.com about polishing aluminum thats really helpful also.

Does that include sanding it to get it smooth?

I don't know, you'll have to ask him. I'm more function over form myself and it's not like the LIM is all that visible. ;) So the smoothing is a moot point for me. If I wanted smooth, I'd have it polished. :)

http://rx7tuner.com/images/Ceramic%20Lower%203.JPG

Thanks EKTwin 93
I looked up robrobinette's how to and it is great
explains in full detail how to do it.
Thanks guys for all your feedback

That ceramic coated LIM looks great. :)

I was thinking of just cleaning the LIM & UIM but what is good for cleaning???
What have you guys used?

The ceramic coating should be easier to care for, too. It won't be as shiny, but it also won't dull and show scratches and dirt as much as bare polished aluminum. It will show any imprefections in the underlying metal surface, though. I had my polished UIM coated, and there are some surface voids/divits that were amplified by applying the coating. It doesn't bother me at all, but if appearance is your main goal, you should be aware of this issue.

I almost had mine coated black or dark gray, but I switched to "chrome" at the last minute. If shiny is your thing and you are willing to care for it, polishing will be much shinier than the ceramic coating. However, there are so many shiny manifolds that it would be cool to do something else. Personally, I think black would be cool, but I'm strange. Powder coating or ceramic coatings come in other colors, too. I know there are a few already out there, but it's a good opportunity to do something unique and keep it pretty with a lower-maintance surface finish than bare polished aluminum.

-Max

max, so you had your manifold polished first so it was smooth and then ceramic coat it? I've been thinking about the same thing.

I've been avoiding polishing parts because of the upkeep on my daily driver but seems to me if the parts were polished and then coated you'd have a low maintenance part that was pretty shiny.

Have a pic?

I had it polished in '99... then ceramic coated in '04 while the car was down... now back on the road in '05. :)

Pics:
https://www.rx7club.com/showpost.php...69&postcount=1
https://www.rx7club.com/showpost.php...1&postcount=21
https://www.rx7club.com/showpost.php...4&postcount=22
https://www.rx7club.com/showpost.php...&postcount=129
https://www.rx7club.com/showpost.php...&postcount=132
https://www.rx7club.com/showpost.php...&postcount=139

-Max

Thanks. That finish looks awful nice and should be very low maintenance. I'll certainly go that route if I decide to "bling" :)

Max
Nice pictures of your engine bay
I noticed you got your car worked on @ Mazdatrix
its funny I just live a couple of blocks from them
They have the cleanest RX-8 out here, and have every part for your needs