I started my recently rebuilt '61 235 a few days ago, and it ran like crap! Been running fine until then. Brand new H/W carb, Pertronics ignition, no apparent reason for the change. I took the valve cover off, started it up, and the #6 exhaust valve is stuck in the open position. The push rod goes up and down like it's supposed to, but the valve is stuck down. Any ideas on why this happened, and more importantly, any ideas on how to unstick it without pulling the head plus all the attached stuff off the engine? I checked the archives and didn't find too much info on stuck valves there. I tried pouring some Marvel Mystery oil down in there and tapping it with a small brass hammer. No luck. I appreciate any and all advice. Thanks
If for some reason the stem galled the guide you're stuck with major work but if it's just varnish then dribbling laquer thinner down the stem several times for maybe a couple days and tapping with your brass hammer may work. New or newly rebuilt engines are way more sensitive to this than those with a few miles on them. Stick a wire in the spark plug hole to make sure the piston is down the cylinder a way before tapping very hard. Your rocker is free on the shaft isn't it? Good luck
What Evan Said Let the penetrating oil soak in a few days , tapping with the brass hammer . If nothing works and you want to try and _force_ it closed so as to expose more of the valve stem for lubricant , you can put the piston @ BDC , remove the spark plug and twirl in a foot or two of cotton rope , being sure to have a big knot on the near end so it won't fall in , then carfeully and gently turn the engine by hand and as as the piston comes up it'll shove the soft rope against the offending valve and maybe force it closed , naturally you'll be spraying penetrating oil on the valve stem like Holy Water.... This is a farm typ Hail Mary last ditch effort to save you from pulling the head , if it works you're golden , if it doesn't the valve & guide were ruined anyways ....
This is why Evan and Nate are my heroes! You guys never cease to amaze me! I was going to suggest a bigger hammer
Well Ya Know.... ...I worked on one of these , once And after I screwed it all up B.E.R. , there was a guy like Evan in town who'd fix it right....
No luck Thanks for the advice, guys. The valve is still stuck. I finally took the head off, tried tapping lightly on the valve itself, and it still wouldn't budge. So I loaded it up and took it to the machine shop that rebuilt it to let them take care of the problem. Guy said it should be ready by tomorrow. Thanks again for the ideas.
What's next?!? OK, so I took my head to the machine shop that had originally rebuilt it, the guy took care of the stuck valve, no charge, and I picked it up the next day. Invited my daughter and her strong husband over for dinner, and "Oh, BTW, can you help me set the head back on my truck engine?" Got everything back together yesterday, started 'er up, and it ran like a champ. Oil dripping off the rocker arms, looking good. I let it run for a little while, idled it down, and then noticed no more oil dripping from the rockers. Checked the oil pressure guage, ZIP, and immediately shut it down. This morning I pulled the distributor, stuck my homemade oil pump turner attached to a drill into the distributor hole, got oil up to the rockers and pressure on the guage up to 60#. I put the distributor back in, started it up, and let it run for about 10 minutes. Good pressure and flow to the rockers. Has anybody had this problem before? I can't figure out why it would have just stopped pumping like that
Well ; Sometimes the dizzy tang isn't fully inserted into the oil pump's drive slot and if you tighten up the dizzy's clamp , it cannot settle down that last 1/8" and so it'll slip . Also , it normal for the oil pressure gauge to almost rest on the peg @ hot idle and not be sufficient to push oil up to the rockers @ idle speeds . My '57 235 has barely enough oil pressure to allow a 1/32" gap between it and the peg when it's idling hot . As soon as I goose the throttle , the oil pressure goes up and @ road speed , it pegs the gauge . Sounds like you've got a good , honest machinest , go take him a 6 pack of soda or beer , if appropriate .
