dlw

I just got through pulling the intake off and shined a light on the valves to see how they looked. Keep in mind I only have a few thousand miles on these heads. AND, they look like as car with 200 thousand miles on it! Every valve has black deposits clear up the stem. And the valves at the #1 cylinder, where I was having the fouled plug, had at least a teaspoon of oil sitting on it.

Maybe I dont have bad rings after all!

Its always something!

geezer

They look like black Christmas trees don't they? That type of crud will really screw up your air flow. Are you sure you put the valve guide oil seals on? You may want to think about machining the guides for a "Perfect Circle" type of seal. Much better than those stock "O" ring type.

69 N.O.X. RATT

I posted something about this a few months ago, it is probably sucking oil from the galley through the intake gaskets into the runners. Hard to believe all the guides are bad. Make sure you seal upp the intake gaskets real well when you put them back together

dlw

The gaskets looked good and the front and rear looked like it had a good seal also. The runners seamed to be pretty clean. And there is varying amounts of gunk on the valves. I have been told that there was a certain type of seal that was used on these heads that proved to be bad and they changed after I bought mine. (SR Torquers)

I'll know more in a day or so.

Jvette73

For valve seals try Crane Cams PN 99819. They solved a serious oil controll problem for me. They are positive seals that lock down over the guide. They do not require machining to install.

Vetterodder

Buildup on the back of intake valves on a car with a big cam isn't unusual, especially if it spends a lot of time at idle (long warm ups, lots of fiddling, etc.). Over pumping the carb on at startup makes it even worse. At low velocities, the fuel doesn't stay suspended in the air and wets the back of the valve. The heat coming through the valve exaporates the light molecules and they are burned the next time the valve opens but the heavier molecules (gas is refined from oil) bake onto the valve. That coating absorbs more fuel and the problem quickly becomes worse.

As already suggested, oil going into the intake ports from a gasket leak or bad valve guides will be much more severe and will occur much more rapidly. #1 definitely has this problem but the others could be just fuel deposits. If it the oil is leaking through the gasket the new gasket for reinstalling should take care of it but I'd still be inclined to replace the valve seals on #1 just to be safe.

To clean up the mess you already have, back off the rockers on the intake valves, spray carb cleaner, Gunk, or whatever, down the ports. Use a stiff brush (put some heat to a tooth brush and bend it so that the bristles are at 90º to the shaft if you don't already have something suitable. A gun cleaning brush is much stiffer if you have one) and scrub as best you can through the ports. Use a wet dry vac to suck out what you can. Adapt some smaller diameter tubing to the vac so that you can get to the valves. Pour a mixture of about 70%trans fluid and 30% fuel system cleaner (Chevron TCP is my favorite) down the ports, filling until as much of the remaining deposits are covered as possible. Let sit overnight and use the vac again. DO NOT SMOKE OR ALLOW ANY SORT OF FLAME NEAR THE VACUUM! Mixed with air, this stuff can be explosive. Thoroughly rinse the shop vac with water several times.

dlw

Good advice guys! But you know this is a great excuse for a better (more horsepower) set of heads. It goes like this. "well dear, bad news on the corvette! looks like I need an expensive part" Thanks honey, I knew you would understand!" :D

Vetterodder

QUOTE]Good advice guys! But you know this is a great excuse for a better (more horsepower) set of heads. It goes like this. "well dear, bad news on the corvette! looks like I need an expensive part" Thanks honey, I knew you would understand!" :D [/QUOTE]

I like your attitude!! It's always worked for me :).