Best way to clean intake passages?
 

I’m in the middle of a valve replacement job and before I fit the new valves, I’d like to clean out the decades of black buildup in the intake passages. It’s black tarry stuff about 1/16” thick.

Is there any chemical that would easily dissolve it? If not, what’s the best method? I have a small dremel tool as well as an air-powered die grinder.

Re: Best way to clean intake passages?
 

Is the block bare? If so, your auto machine shop can hot dip it. I believe the babbitt can be damaged by some solutions, so be careful with that.

Re: Best way to clean intake passages?
 

there is some smaller diameter knotted wire wheels cone shapes. that have 1/4' shafts that are tough enough to get a lot of the stuff out. they work better once they have been used and the knotts are starting to separate and the wires will stick out sideways, but still won;t get into all the recesses. and be careful of the seats.

i can't figure how to ad a picture maybe someone could do that for you?

Re: Best way to clean intake passages?
 

something like this. i dug mine out to show you. once they get worn they work better. but you will still have to dig some out by hand. i use cordless drill to turn them.

Re: Best way to clean intake passages?
 

No, it's in the car.

Re: Best way to clean intake passages?
 

That should do it

Re: Best way to clean intake passages?
 

I use oven cleaner spray and hose off with water.

Re: Best way to clean intake passages?
 

take the intake manifold and dunk it in 5 gallon bucket with about 1-2 gallons of gasoline or kerosene and let it soak. shaking the bucket in a circular motion sort of like a washing machine will also help to break loose the crud. take it out and either spray with brake parts cleaner to strip or let it dry for a few days, then repaint it and hang it back on the car.

Re: Best way to clean intake passages?
 

Me too. Small stainless steel brush like this one https://www.harborfreight.com/steel-...ush-69525.html really helps.

Dremel or die grinder with a small diameter cup brush to finish off.