cleaning carbon buildup on cyl heads???

i took off the heads on my ford 302 to replace a blown head gasket. it has some carbon buildup on them. can i clean them up with a slow rpm drill with a cup style wire wheel? would that scratch them up, or is it best left alone?

thanks

 

cast iron heads? no problem.

 

Yes !that should work fine,just make sure none of the wire wheels wires get left behind ,or wedged under one of the valves.you can also buy stuff called combustion chamber cleaner,not sure who makes it but it works great!

 

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you can also buy stuff called combustion chamber cleaner,not sure who makes it but it works great!

[/ QUOTE ] hoppes no.9 works good for that...

 

yes they are cast iron.... thanks guys

 

So.... while ya gotem off why not get out the grinding paste and seat the valves, only a couple of hrs work

 

Grinding paste? Do tell; I'm about to take the heads off my motor (cast iron heads completely rebuilt in '02 with not a whole lot of mileage on 'em), so was wondering 'bout it, too.

 

The Combustion Chamber Cleaning stuff that I've used before, that came highly recommended, was Mopar Combustion Chamber Cleaner. I got if from a Chrysler dealer for about $5 a can. The instructions that I got to clean the chamber with the head in place was to squirt the contents of a whole can into each of the spark plug holes (that was a 4 cylinder so maybe 2 cans for a V8. The person I talked to said to let it sit overnight or for at least 7 hours or so. The next morning, they say to siphon each cylinder to avoid hydrolocking, so I rigged up a clear tube onto my Shop Vac that would fit into the spark plug holes. I didn't believe the chunks of carbon that were getting sucked into the vacuum. They recommended running the car up to operating temp and changing the oil ASAP after that.

I wouldn't mention it if I hadn't seen ALOT of carbon chunks come out, so I guess the stuff works pretty well.

 

If you haven't put many miles on them since they were rebuilt, and if they were lapped when the rebuild was done (I've had a couple machine shops try to tell me that "nobody does that anymore", but I'd never invest all that $$$ in a rebuild without spending the hour or two to lap in the valves), they may not need it, but it only takes a little while. Pull the valves, number them, clean all the carbon off them, put a thin film of valve grinding paste (I use the stuff in the green can- Clover Brand???) on the sealing face of the valve - don't get any on the stem, or you'll fuck up your guides- slide the valve into the same chamber/guide that it came out of, stick one of them suction cup on a stick things on the head of the valve, and twist it back and forth between your palms like you were trying to warm them up, pushing the valve against the seat with a little force. Doesn't take much time- 20 seconds, maybe. When you pull the valve out, wipe the excess paste off, and there should be a nice pale gray line on the sealing face of the valve and the seat, hopefully around the center or a little under the center of the face. Make sure you clean all that abrasive stuff up before you put the head together.

Or at least that's how I do it.

Oh, and that Mopar stuff- I'm sure it's sold under a different brand name by whoever actually makes it for Mopar, but most Chrysler garages will have it. The shit works- and good advice on the shop vac, oil change procedure if you do it in the car- I wouldn't have thought of that one (I'm kinda slow). It'll help keep all those loose chunks from getting stuck between a valve and a seat, too.

 

Lapping valves is always a good idea, and be sure to clean, clean, and reclean the valve compound after your done. What works for me and is better than that wooden stick with the rubber cup is to get a piece of gas line hose about six inches long and put it over the valve stem 5/16 or 3/8 dia whatever fits tight over the stem. put the hose between your hands and make that valve turn back and forth while pulling to put pressure on the seat. Lift the valve every 15 or so seconds and reseat it in a different spot. Keep doing it until you have a nice satin finish on both the valve and seat.

 

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hoppes no.9 works good for that...

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Or blackpoder solvents, like Butch's Black Powder Bore Shine.