Ok to make a long story short, TOO LATE. I Have a custom 300 with a 6 banger in it. The car has been sitting since 1970 with 26000 Original miles. After doing all electrical and brakes and cleaning the gas tank about 5 times with about 20 gallons of gas we started it. had 2 stuck valves. I got them loose after working them up and down for a while the car started and ran great. Day 2 the intake valves were stuck again. Took all the Rockers & push rods apart cleaned and loosed up the valves. Couple days later tried to start and bent 3 push valves. Valves stuck again. Cleaned and loosened them up again. Cleaned the gas out again because the fuel filter was all red. "3rdfilter that i used" Drove the car today for about an hour. Ran great chicks were looking all was great. Changed the oil tonight tried to run and valves stuck. SHIT!!!! Droped the gas tank and found 2 inches of slug in the bottom. Very nasty shit. Would that have been my problem? The bad old sluge that I thought was cleaned out mixing with the new gas. Need input?? Please help. I also now need a tank because the top part of the tank where the sending unit would rest on is rusted away. Can that be fixed or should I spend 2 bills and get a new one. Sorry for the novel but I need to know from the pro's. Thanks Tony
im not a pro but i can offer my opinion...buy a new gas tank...its junk. also id try to work some atf or pb blaster in around the valve guides while moving the valves. is it exhausts sticking?
It the intake valves that are sticking and when I meen sticking I mean sticking. I takes about 20 min. of pulling and tapping down with heat and a lot of WD to free them up. Would the old gas be varnishing them up when the cool???
ive never heard of that happening, but i suppose its possible. im thinking that after all youve done and they keep hanging up that the guides are galled and the head should come off to have the guides honed
That what I was thinking but Im going to get a new tank and free up the valves run leaded fuel which they sell by me house and see if the next day the stick. I hoping not. Thanks
Years ago I ran half atf & 30W got it hot a drained it out with success. Aside from tearing it down, don't expect a magic fluid to get you years of running out of it. Tim
Try using ATF or Marvel Mystery Oil (Or one of the penetrants already mentioned) instead of WD-40. WD-40 is good stuff for its intended purpose but it ain't a good penetrant. quote=bugbaron;2251872]It the intake valves that are sticking and when I meen sticking I mean sticking. I takes about 20 min. of pulling and tapping down with heat and a lot of WD to free them up. Would the old gas be varnishing them up when the cool???[/quote]
I like Marvel Mystery Oil, if you're going to keep breaking them loose, add some to the oil and fuel. We use it here on large radial aircraft engines, works good, but what you have we call a Seized valve, and the cylinder would come off for that (head is screwed onto the cylinder). No I don't think the stuff in the tank was doing it (could be wrong). Even the really high lead aviation fuels won't do that, well not that fast anyway. For that to be getting on the valves that fast, I would expect it would plug the needle and seat up (completely). As previously mentioned, the best way at this point would be to tear the head off and fix it.
I agree with the marvel mystery oil comments, a quart in the gas and one in the oil, if that doesn't do it then a teardown. Also get a new tank, it's cheap insurance about problems later on. Good Luck, Mike.
The scenario that you write about is common with cars that have been left setting for long periods of time. What has happened relates to the evaporation of the gasoline and the remaining fuel reverting to a varnish base liquid. While it is still flammable the old fuel produces a film around the intake valve as the old fuel flows around it during operation. As long as the engine is hot it runs Ok, as soon as the engine is stopped and the engine cools down this varnish film on the valves hardens and takes the clearance out of the valve stem to guide, thus causing a stuck valve and relating bent push rod upon trying to restart the engine.. The quick way to free the valve up is to apply pressure to the stuck valve and spray the valve stem with Brake klean to break down the film followed by Wd 40 or some other light lubricant. After freeing up the valve remove all the old fuel from the tank, or remove the tank and have it cleaned to remove the varnish sediment in the bottom. Upon refilling the tank and restarting the engine you should use a pint of Marvel Mystery oil in the fuel or some other top lube for a couple of tanks of gas.
Run it with the valve cover off, and hose down each intake stem with a good solvent (brake kleen as mentioned above is excellent) while the engine is running. This should dissolve and scrub a good portion of the varnish off the stems and guides. Also run a little Marvel Mystery Oil mix in the tank to give the valves a little extra lube. And a high dosage of fuel system cleaner for a couple of tanks might also help.
I ordered a new tank and sending unit. I freed up the 3 stuck valves know just waiting on push rods and I will put back together and try out some of your advice. Thanks A lot.
Just to let you guys know I put a new tank new sending unit, used ATF and leaded gas and the valves have not stuck since. Thats for you help!! HAMB rocks!!
wd 40 is not a lubricant...it's main job is to disperse water (wd stands for water dispersing). you need to use an oil based product that is an actual lubricant...like marvel mystery oil. pb blaster is an excellent penetrating lubricant. so many times people mistake wd 40 for being a lube....and it really isn't.
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