I'm currently rebuilding my 302 and the intake is caked inside with carbon and oil and other debris. Been looking for a something I can use to pretty much just give the intake a solvent bath. I seen people use NaOH (sodium hydroxide I think) and was thinking about trying it. I wanna to be able to just let it soak in the bath and pressure wash after and be done with it. Any ideas?

 

I assume you're doing this off the engine. Sodium hydroxide should work. You can also use Easy Off oven cleaner. Both may also remove any paint you had.

 

yes the intake is off of the engine. And alright thank you! I'll give it a shot

 

It's best to remove the baffle plate attached to the underside of the intake manifold.

I agree with the oven cleaner technique, but be sure to use protective gear, as the stuff gets flicked all over when you brush it.

I attach a hose to a hot water supply (laundry sink, hot water tank) to clean outdoors, as heat hugely improves cleaning.

Another technique I worked out for smaller items is to sit them in a five gallon pail of gasoline overnight or longer and then carefully remove and drain without brushing. Then I put the item in the sun until it evaporates dry and clean with soap and water. The beauty of this system is that the gasoline leaches out the oil, so the remaining dirt easily washes off with just soap and water.

Since there was no scrubbing in the gasoline, it stays fairly free of dirt, so I let it settle for a couple of days and pour it off into another clean white pail for reuse in one of the cars that uses cheap inline fuel filters. If you decant carefully this technique keeps the fuel quite dirt free however. The dissolved oil does no harm.

 

I'd be careful re-using gasoline that has been used for cleaning. I tried this once by pouring it through a coffee filter in a funnel, so it "looked" clean and clear. But it left a layer of very fine mud in the carburetor bowl that really messed it up.

I would re-use gasoline that has been used for cleaning to clean other parts.

 

If it is an aluminum manifold I would use sodium hydroxide sparingly it will eat aluminum. If it is cast iron then you can soak it in sodium hydroxide. An automotive machine shop probably wouldn't charge you much to clean it. And it would come back really clean.