MTFCA Forum

I am disassembling a 26 engine and two of the exhaust valves are rusty and won't come out. Has anyone tried heat and rapid cooling to free them up or can they be cut off and drilled out?

I pull the lifters and use a drift to tap them out from the bottom side.

Patience and pentrating oil. Very light tapping with a light hammer. If the valve is up off its seat, heat may be of benefit. If the engine is dry and free of oil, bathroom cleaner that contains mild acid can be helpful.

As Pat suggested patience and penetrating oil are essential. The photos below are from a 1927 block of mine that a previous owner apparently tried some heavy brute force to free the pistons and valve. All four pistons had their tops punched through and four of the valve heads were broken off. The connecting rods had even been torched in two, presumably as the easiest way to disconnect the crankshaft. As shown, I did eventually get the pistons and valves out. I used a goodly sized metal bar as a punch rod to bang on the pistons from the underside, resting the rod on the piston pin area. If you can eventually get the piston to budge just a bit, you are home free. Just keep squirting penetrating oil around the piston as you bang it up and down to increase its range of movement. As for the valves, first remove the pin holding the spring seat so the valve isn’t held down by the spring. As Joe Bell said punch the valves up from the underside. For the valves having their heads above the surface of block use channel lock pliers to grab the heads and apply a twisting force. Again, if you can get the valve to move using a drift punch and/or the channel locks, then use the oil and go up and down, back the forth to wiggle the valve out.

Best of luck to you!

Rich C.

One word. “Kroil”. Then, let it sit and penetrate before punching out from the bottom. Jim Patrick

Before adding any penetrating fluid, clean as much rust and crud off the valve stem where it comes into the valve chamber using wire brush, sandpaper, file or whatever. You have enough to deal with, with the rust between the stem and guide so don't need any extra from the exposed part of the stem too.

Don't make my mistake. Just to get the valve freed up, I alternately pounded on it from the top, then the bottom, etc., etc. When pounding from the top, I managed to break the valve guide off of the block. No, I was not pounding all that hard... Junk... I suppose I could have had a new guide pressed in, but instead I donated the block to Piquette for use in their station assembly display.

Great suggestion Mark! Muriatic acid is a great rust remover to use on the stem. Paint it on with an old small paint brush. Muriatic acid is not good for cast iron though, so keep it off the cast iron. Keep a bucket of water with baking soda mixed in to neutralize the acid if any gets on the cast iron or yourself. Jim Patrick

On my B597 block I cut the bottom of the stems off flush with the underside of the block. That got rid of all the rusty stem below. Then I punched them out from the bottom as Joe Bell suggested.

Allan from down under.