my 92 LB9 was never cleaned by the previous owners. I am taking the top end apart and was curious if anyone has found something that cleans the plenum and runners without polishing them. I just want to return them to clean while removing any oxidation so they still looks stock.....soap just won't remove surface oxidation.

Any experience or ideas?

 

The only thing that works for me with cast aluminum is an abrasive, - sanding or sand-blasting, scotchbrite wheels etc...

Caustics work by the process of oxidation, and thus defeats the purpose.
I've tried many other ways with no success.
If there's a better way hopefully someone will post it here.

 

Lookin for the same... Don't want to polish them, just want them clean looking

 

the best thing i've used was carburetor cleaner, not the spray type, but the stuff that comes in the 5 gallon buckets that you find in auto shops.
it would take at least an over night soak if not longer, then wash the carb cleaner off with a pressure washer. but even that doesn't completely clean it. there will still be places where the oxidation is too bad and has eaten into the metal, and of course it also takes some of the paint off too.
the next best thing is to spray it down with some good degreaser and then a trip to the car wash. on the way home get some scotch brite pads and paint of the right color and go to town.

 

The insides are likely to be coated in carbon/oil buildup. I would do a good soak in a hot tank or other cleaning solution first. Then media blast the outsides with a 120 grit glass bead. That will make it look like fresh aluminum again.

 

I'm probably the only guy that doesn't like cast aluminum to be sandblasted. To me it takes away the true cast look and softns it..Most people won't take the time to mask off the machined surfaces/ threaded holes either and that makes it a bit harder to clean the surface after a gasket has been on awhile.
There are a few ways that the pro restoration shops do it and it looks great. I found a story on it once and didnt save it.... ugh.

 

!!! what good are you then ?

I'd like to know what they use. I don't really like to have to blast them either.

Years ago someone said there was some special chemical that was used for restoring old carburetors and the like, but I never saw it personally, nor do I know the name of it.
Most of the chem-dunk stuff out there will either dissolve the aluminum or turn it black or white. I have tried a bunch, but no luck.

It must be some kind of trade secret.

 

http://www.autozone.com/autozone/acc...ier=40265_0_0_

try some carb cleaner and then use this stuff worked great for me just spray it really good had my plenum and runners looking like new

 

well, i got the plenum and runners off last night so i am going to start cleaning them... starting with the least aggressive... see what i get. I am 3 or 4 ideas in mind and i'll try them on the undersides to what I get before going full bore.

Holy crap! getting those 6 bolts at the bottom of each runner is a pain.... I thought I read a typo and it was 6 total, 3 per side.... I had to hunt for those other 3.....

 

This guy on the forum used B-12 Chemtool and it appears to have worked great

https://www.thirdgen.org/forums/afte...erryman-b.html

 

I read that post and went out and bought b-12 did not seem work any better than cheap old carb and brake cleaner

 

i use a product called "greased lightning". it will clean crud off the aluminum parts very well

 

I've had good luck with cast aluminum wheel cleaner. Not the stuff approved for use on clear coated wheels, but the stuff for bare cast aluminum wheels.

 

i believe the OP is talking about the oxidation on the outside.
the harsh carb cleaners will remove some of it, but nowhere near all of it.
B-12 does great at cleaning the sludge from the inside and grease from the outside, but it still doesn't do much for the oxidation.
the wheel cleaner will probably remove as much if not more of the oxidation than carb cleaner will, but its not a simple spray it on and wash it off deal, there is going to be some elbow grease involved.
if the metal is etched, then either some metal has to be removed, or cover it in paint.

 

^ +1 it's a pain.
Degreasing is the easy part.

 

After I degrease the part,
I use muriadic acid from the big hardware stores. put it in a plastic spray bottle and spray the part while wet. test the part, dont leave it on to long..
BE CAREFUL with that stuff, gloves, mask, face shield and everything. its wicked.
burns on contact and the fumes are nasty.
BE CAREFUL.

 

Muriatic acid is what I use to balance swimming pool chemistry. It also is called Hydrochloric acid and is very nasty. I got a vapor burn on my lungs from handling it to closely. Hurt like hell for a week when I would breath. Must wear chemical proof gloves and a vapor mask when handling. Nasty, Nasty Nasty stuff.

 

I used Muratic acid on some cast aluminum parts back around 2000 and it turned them black and yellow stained.
Had to use abrasive to get that off.

I've tried that and Vinegar with similar results though the Vinegar is slower and safer. With both of those if you leave your part in too long it won't be there when you check back.

Best thing for me with some parts is to use a brass wire-wheel.
My vibratory part cleaner can clean some of them, - smaller stuff.
Big things like intake manifolds just take a lot of work & time with abrasive.

If the oxidation is very shallow you can do a good cleaning with steel wool pads (not the kitchen ones).

I seriously wish I could find an easier way though.

 

I gave it a go today..... the best results seem to be by using MarineClean from POR15. A nonsolvent, water based cleaner. scrubbed it with a small steel brush. Steel wool does clean up some of the oxidation.

I also tried a steel brush wheel in my drill but this was causing too much sheen. I also tried a spiral buff and sisal buff in my stand buffer but they didn't do much.

 

there is an easier way, but it costs more.
just pay someone else to clean and polish it,... LOL

 

sand blasted mine and painted them a nice silver, looks factory and is super easy to clean..

 

CLR.

 

glassbead them ... they will come out nice.

 

I tried to clean mine off today with dish soap and a old sponge. Didnt work. I may just spray carb cleaner or a degreaser to decontaminate the finish and and paint it with an engine enamal "Gloss Black".

 

Which CLR product are you talking about?
http://www.shopclr.com/index.php?pag...54-b-302471373

 

Marine paint remover does good job. brush it on let set and hose off. Then use brake cleaner spray or acetone. If I want color, I use a really good aluminum wheel paint in whatever color I want. holds good with out scratches.

 

Well, since this wasn't a show quality resto....and I am cleaning the car up for daily driving...I went at it with degreaser, a stiff steel brush, and arm power....(see my comments above for things that didn't work too well) looks a lot better..... not as nice as some of the engines I have seen here but its a good start for a car that has never seen much TLC.

The plenum still stayed darker than the runners...and I didn't get to clean the throttle body.... so for now the colors don't all match...go figure.....

Thanks for all the suggestions. If we find other solutions, I may pull the runners again.

 

Eagle One Mag Wheel Cleaner (for aluminum / non coated wheels) does wonders on Turbocast wheels, probably much the same for TPI unit...
Spray on, hose off... can brush lightly if needed...

Rafael

 

I looked up the product that you mentioned. There's a few pictures that do show an improvement, but not the new like finish.

 

Brake/parts cleaner the best thing it will take a few cans the whole tpi I will say 10 cans to be safe it works I just used it

 

I'm in the process of working on this puzzle myself. I have 3 of these cars so I've already tried a couple different methods. I tried just scrubbing and cleaning with a good degreaser, then I painted them. Paint did not last long. I tried sanding them down to clean metal but as you know you can't get the sand paper into all the areas that can be seen with the eye.

So now I have found the best solution I can find so far. I bought a blasting cabinet. First I tried 80 grit glass beads. It certainly cleaned the runners but the glass beads left a gritty texture to the finish. So I then tried SODA BLASTING. Much much better than glass beads. The finish is much less gritty. The glass beads took it way down to the pure white metal aluminum which is good but it didn't look stock. to me stock was more of a dull silver look. The soda is much closer to stock looking and much smoother. Next I am going to try some plastic beads because I've heard that they can actually "polish" the metal if you use low air pressure. But beware, blasting will not cause, but it will EXPOSE any tiny little dent in the runners and make it stand out like a wart.

I realize that going out and buying a blasting cabinet is not realistic for many guys. I bought mine because I will use the heck out of it for other stuff too. But blasting is so far hands down the sure fire way to get them clean in all areas. Just don't use a media that is aggressive in any way.

 

For those guys who suggested painting, I've done that before too and honestly it's a good way to go. Go to your local Harley Davidson dealership and buy a couple cans of paint called "silver bead blast". For all the world it looks like fresh cast aluminum, it goes on easy and dries super fast and is very durable. It also seals up the aluminum so you can clean it with soap and water later on and it will always look like new. I've been painting cylinder heads with it for years now and you can't tell a painted one from a new one. Just tossing that out there...