Heavy carbon buildup removal

[travis]

I’m working on a couple different projects with stock iron intakes that will retain a functional exhaust crossover. Both also have the typical sheet metal shield underneath the plenum in the valley area that are packed full of heavy cooked oil deposits. I’m spending way too much time drilling, chiseling, and grinding this stuff out. Is there something that will help soften or dissolve this stuff?

I’m also assuming that it is acceptable to cut the rivets to get these sheet metal shields off to clean under them, then rivet them back in place afterwards?

[ec1]

Best thing is to bake and shot blast the intake. Probably around a $60 to $100 labor cost at local shop. Or if you really want to remove it chemically -carburetor cleaner. The kind you soak the whole carb into. You're going to need a way to soak that area. I think Gunk sells it. As for the rivets...chisel them out or off whatever happens first. Then drill and tap or I always just tig weld the plate back on through the holes with nickel rod. Remove the sheet metal and EVERY fitting/plug/stud before the bake and blast.

[BillK]

Travis,
On the Chevy intakes I have found that if you get a real small chisel or sharpened screwdriver under the corner of the rivet or the sheet metal you can usually pry the rivets out. Then after cleaning I just tap the holes and use a small screw to hold the shield in place.

[PbFlinger]

I have used a needle scaler on these with good results after heat shield removal. Of course if it’s all oily this won’t work. Backyard: spray on a can or two of dollar general oven cleaner, scrape, wire brush, hose off & let dry. Then alienate the neighborhood with the needle scaler.

[Schurkey]

The way I remember them from decades ago, the heat-shield rivets have "threading" stamped into them.

Chisel them counter-clockwise (lefty-loosey) as you pry them out, and they back out pretty easy. Smack the shank to distort the threads a little, pound 'em back in when you're done.

But I haven't done this since Fido was a pup. So I might be hallucinating.

[PbFlinger]

After doing one with the needle scaler you will crawl 11 miles on your hands & knees to a shop with an oven & a shot blaster, and give them a week’s pay to clean your intake.

[Schurkey]

Just for giggles...

Anyone have a part number for the heat shield on SBC intake manifold? I've got some aftermarket manifolds that have the heat shield holes drilled, they look like they'd take an OEM shield...but of course they're not supplied with the shield.

[KnightEngines]

1mm cut off blade in an angle grinder, slot the rivets & remove with impact screwdriver.
Caustic bath is your friend to remove the carbon, blasting can leave crap in the runners that you can't get out but the motor will suck it through!

[MadBill]

Back at dawn of time lye (sodium hydroxide) was the go-to for decarbing iron motorcycle heads. You could buy it in supermarkets; it was used for making your own soap (!) Don't know where/how easy it is to get now.
https://www.castironcollector.com/lyebath.php

[David Redszus]

Back at dawn of time lye (sodium hydroxide) was the go-to for decarbing iron motorcycle heads. You could buy it in supermarkets; it was used for making your own soap (!) Don't know where/how easy it is to get now.
https://www.castironcollector.com/lyebath.php

Sodium Hydroxide is readily available at almost every hardware store. It is sold as a drain opener in powder form and is mixed with water. Don't breathe the fumes. Don't use on aluminum parts.

[travis]

I didn’t even think about drain cleaner…but some oven cleaners seem to work pretty well

[David Redszus]

I didn’t even think about drain cleaner…but some oven cleaners seem to work pretty well

Guess what's the active ingredient in over cleaner.

A 5 lb container of sodium hydroxide costs about as much as a single spray can of oven cleaner.

[JohnP]

David: I sent you a PM yesterday, don't know if you saw it yet. Look for an email from me as well.

[m880]

I’m working on a couple different projects with stock iron intakes that will retain a functional exhaust crossover. Both also have the typical sheet metal shield underneath the plenum in the valley area that are packed full of heavy cooked oil deposits. I’m spending way too much time drilling, chiseling, and grinding this stuff out. Is there something that will help soften or dissolve this stuff?

I’m also assuming that it is acceptable to cut the rivets to get these sheet metal shields off to clean under them, then rivet them back in place afterwards?

PB rust blaster removes carbon deposits very good

[shoedoos]

viewtopic.php?f=1&t=14901