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Login to post Forums » Grassroots Motorsports » Cleaning Intake Ports w/ Heads on Engine - Advice?

Feb. 2, 2012 9:40 p.m. JohnyHachi6 Reader

So, I'm working on one of the DOHC 32v mod motors (Ford) that has the B heads. Since only one intake runner/port/valve per cylinder gets fuel, the other intake ports have an unbelievable amount of carbon buildup - really nasty.

I've got the engine sitting in my garage and want to clean out the affected intake ports, but don't want to pull the heads. The carbon is really an issue as the engine has low compression on 3 cylinders as a result (I can see/hear air shooting out past the valves on the ports with bad buildup). SO, what do I use to clean this up and how do I keep it from all getting into the cylinders?

I was thinking about putting the engine on a stand so I could turn it upside-down and spray some cleaner (maybe oven cleaner?) up into the ports then scrub them out with a small brush and repeat. Thoughts?

Here's what the ports look like (same on all 8 cylinders). Can you guess which one gets fuel? (Yes those giant blobs of crap are stuck to the valve stems too)
Feb. 2, 2012 11:35 p.m. DILYSI Dave SuperDork

Fill the runners with ATF and let it sit for a few days. Empty and scrub with a brass brush. Repeat as needed. It WILL get into the cylinders. Just pump it out with no plugs installed and be prepared for a smoke show upon first startup.
Feb. 3, 2012 12:18 a.m. JohnyHachi6 Reader

Oh, that sounds like a great idea. I hadn't thought about using something oil-based that would be OK to get into the cylinders. I might give that a shot.
Feb. 3, 2012 12:53 a.m. novaderrik Dork

pull the heads.. it's worth the price of a set of head gaskets and some head bolts to save the aggravation of trying to not let stuff fall into the engine.
Feb. 3, 2012 7:08 a.m. Gearheadotaku SuperDork

isn't there some sort of walnut shell process?
Feb. 3, 2012 7:11 a.m. Streetwiseguy SuperDork

Couple of decades ago BMW had a process for shot peening the intakes with walnut shells.

I'd think very hard about pulling the heads.
Feb. 3, 2012 9:05 a.m. 44Dwarf Dork

Toyota had a walnut shell procedure in early 90's....
Feb. 3, 2012 9:21 a.m. pstrbrc New Reader

Soda blasting? Any idea how harmful baking soda is to an engine? Turn the block upsidedown to do it and after blasting connect air to the spark plug hole and manually rotate the engine to blow what's in the combustion chamber out the ports?
Feb. 3, 2012 9:28 a.m. cwh SuperDork

I think that I would bite the bullet and do it right by pulling it apart. That way you know it's done right with no worries. It has to be a hassle with the cam drive chains etc, but, do it once, be done with it.
Feb. 3, 2012 9:45 a.m. Curmudgeon SuperDork

The Tercels would build up carbon in the intake ports and that was blasted out with crushed walnut shells like 44 mentioned. Never saw an engine damaged by that. But Dave's idea of ATF (or WD40, seen that used to unstick carboned apex seals) would be even less likely to leave any clogging type deposits.
Feb. 3, 2012 9:50 a.m. Conquest351 Dork

I agree with the ATF, but I mostly agree with pulling the heads. Not only are you going to make sure you're cleaning them up, but you can go ahead and clean the combustion chambers too. If you're feeling good about yourself, go ahead and gasket match port them.
Feb. 3, 2012 12:07 p.m. JohnyHachi6 Reader

Thanks for the replies. I'll have to give this some thought. I'm leaning towards giving the ATF a try and if it looks like I can't get it cleared out well enough I'll just pull the heads.

It's a junkyard engine, so it's not the end of the world if it doesn't work out that well.
Feb. 3, 2012 12:27 p.m. mad_machine SuperDork

as the engine is out of the car... 3/4s the aggravation of pulling the heads is already done.

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