I installed a new Edelbrock Performer RPM intake (as-cast finish) on my Chevelle last June (2004). I stopped driving the car in November and didn't start it again until April due to transmission work. The intake looked fine when I parked the car. After sitting all winter, it has discolored patches all over it. The patches are a light rust color. The discoloration is over the entire intake, not local like a carb leak would cause.

Has anyone else seen this?

Any ideas how to clean it?

carb cleaner seemed to clean my intake pretty good, give it a shot..

Laquer thinner works great

I have the exact same problem with my intake. I have a ZZ454 and and the intake looks kind of crappy now. I was not able to clean it with anything. The worst part is that although GM painted the engine black, they left plenty of areas that were not painted and they all rusted. Now eventually I have to pull the engine and paint it right....

I just tried carb cleaner and laquer thinner. Neither worked. Seems like the discoloration has penetrated the aluminum?

I am going to try edelbrock@edelbock.com. I'll let everyone know how they respond.

I had the same problem. Nothing would take off the stains. Took some Plasti-coat aluminum paint and sprayed some in the cap and used a broad flat brush to dab it on the intake. Not perfect, but a lot better than it was.

Initail Edelbrock (canned) response:

Dear Enthusiast:

Thank you for contacting Edelbrock. Your email is currently being
processed, and will be answered by one of the most comprehensive Technical
Departments in the Automotive Industry. Your email will be answered in the
order it was received. If you need immediate attention, you may call our
tech line @ 800-416-8628, 7:00 am to 5:00 pm PST, Monday through Friday.
For Motorcycle Carburetor inquiries, please call 877-888-7504, 8:00am to
5:00pm PST, Monday through Friday.

Thank you for your interest in Edelbrock Products. We look forward to
assisting you.


Edelbrock Technical Department

My Air Gap did the very same thing. What gives?

Jeff,
Almost anything aluminum will discolor or corrode if not stored properly. Its really hard to keep an aluminum intake from looking bad after a year or so if you drive the car at all. Any kind of salt conditions on the roads will really make it bad. What I have found works best is to clean it as good as you can with soap and water, dry it off and spray in a light coat of Seymour Dull ALuminum Engine Paint. It keeps the corrosion off and if it gets dirty, its real easy to touch up.
One other thing to look at is your engine grounds. I suppose it's possible that if the intake and engine in general is not grounded well, it might be setting up some sort of galvanic current and causing corrosion. Big problem in marine applications.

Moisture is the number one problem that causes your problem. Even in good Ol Sunny Cali we have that same problem, But for me it happen to my Brand New Edelb. rpm Air gap, becuase of the excessive rain that we had this year. Mine wasn't bad and I scrapped it off with a brass wire brush tooth brush size. That brush did not change the finish. Like I said it wasn't that bad to start with. When I say moisture, I'm not talking about rain pouring onto manifold, just the dew in the air the settles at night.

I used some Eagle One aluminum wheel cleaner to get some fuel stains off of an Edelbrock RPM manifold.Worked great,manifold was off the car though.The black spray bottle,for aluminum wheels,not the one for polished wheels,there's several different choices.

Not easy and time consuming. Pull it off and bead blast it. will look like new.

pull it off and get it powder coated or buy a polished one they clean up much easier!! i usually paint the cast ones the same color as the engine due to the nasty stain problems!!

Use Denatured alcohol, every hardware store has it, and it will look like new.A small brass wire brush,like welders use ,will help and plenty of clean rags. A buddy of mine uses this on his cast Edelbrock intake and water pump and they always look spotless.

If you decide to bead blast it, have it done with walnut shells. It will sparkle. Glass beads will dull it. If you want to eliminate the problem entirely, have it anodized. I had my Vic Jr. hard anodized. It never stains. However, hard anodizing will change the color, darkening it up a lot. Soft anodizing with clear will retain the original color but won't hold up as long as hard.

Will powder coating hol up?

What about having JetHot coat it?

Edelbrock ended up calling me. I was pretty impressed. They had no ideas on how to clean the intake or what caused the discoloration (I sent them photos). They offered to clean it for me if I sent it back to them.

I didn't want to deal with the 2 weeks of downtime right now, so I ended up using the Eagle One mag wheel cleaner. It worked well, but that is some pretty nasty stuff. I had to use it very sparingly to avoid contact with other engine parts. The stuff would be very easy to use if the intake is off the car.

Worked well enough to get me through the summer