Sticking Valves and bent pushrods


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By Unibodyguy - 17 Years Ago
Recently I had a friend here in Vegas that has a 55 Ford Victoria with a 35,000 mile rebuilt 292 out of a 57. He drives the car ocassionally and puts on like 3000-5000 miles @ year. Anyway what happened was that in August when he put the car away and parked it until recently just tried to start it. When the car tried to start, it turned over as normal and ran terribly. He said it sounded like it was missing terribly. He pulled the valve covers and saw that a lot of the rockers were either bent or off of the pushrods. Now the car hadn't been run hot just driven normally before being put away. He said after another additional sets of pushrods and re-adjusting the rockers twice @ .019 they did it a 2nd time as well, and not always the same cylinders. He finally called a Thunderbird place called the "Birds Nest' and they told him that it had to do with deposits forming up past the valve on the valve guides and stems  from todays modern fuels and to add lead aditive to his fuel. The additive would help some they said but the best bet was to take off the heads and make the valve guide clearance wider so that the deposits wouldn't be as likely to occur, but to still use the lead additive as well. This motor by the way has hardened seats when rebuilt for unleaded fuel. Has anybody ever heard of such an occurance before?? I sure haven't

                                                                       Michael  

By Ted - 17 Years Ago

I’ve had a similar experience with a rebuilt Y engine and old fuel.  The engine cranked up just fine with the old fuel and I put about thirty miles on it before letting it sit for the night.  The next morning when trying to restart the engine, most of the intake pushrods bent as a result of the fuel varnishing around the valve guides which subsequently caused sticking of the valves and bending the pushrods.  I ended up pulling the heads and thoroughly recleaning all the valves and guides in which to get everything working free again.  Also flushed out all the old fuel and refilled the tank with some fresh fuel and no more problems after this.  In this particular case, all the parts being new and tight exasperbated the problem whereas an engine with some wear and a good number of miles would not have been as sensitive to this.  Todays gasoline shouldn’t be left in the tank for more than sixty days without some kind of preservative being added in which to extend it’s life.

 

The other consideration is condensation as that will also stick the valves and likely stick the exhausts first.  If the intake valves are sticking, check the fuel.  If the exhausts are sticking, then condensation while sitting is likely the culprit.
By Unibodyguy - 17 Years Ago
Ted,

       thanks for your comments, what you said does make sense. What I also thought might of happened was the clearances for the valve and valve guide might not of been right, but I think your theory is better. I know fuel doesn't last at all now a days. If its going to be a while I always put in some gas additive called Stabil, seems to work good for me.

                                                            Michael

By 55Monterey - 17 Years Ago
Ted guided me through the exact same problem. My 55 Merc. sat for 2 years and when I attempted to start it, I too had bent pushrods and such. 2 year old gas and storage in an unheated garage lent itself to its demise. Nothing a top end rebuild wouldn't fix.
By mctim64 - 17 Years Ago
I agree with Ted on the fuel problem, it would be best if we could just fill up on 100LL Avgas, but that gets a bit pricey. Stabilizer is the best course if the car sits for long periods. I wouldn't think an engine with 35000 miles on it would have tight valve guides though.

It is my opinion that guides should be a little on the loose side and I don't like posative seals, it's good to get a little oil on the stems. I don't run any kind of valve seals on my engines and have never had an oil consumtion or smoking problem.

Tim

'58 F-100

When you do have your guides replaced make sure your shop installs true "Guides" eather bronze or cast iron, but stay away from "Liners" they tend to stick and pull out with the valve.

the liner is on the left

By Marc - 17 Years Ago
Wow, I'm glad to read this now. I'm close to firing up my new engine, after the car's been sitting for a year. Think I'll drain the tank first. That stuff should burn OK in the lawnmower.
By 55Monterey - 17 Years Ago
Not just drain old gas but make sure the valvetrain is moving freely before trying to start it. If I would have done that it would have saved me lots of time in rebuilding the top end.
By Joe Johnston - 17 Years Ago
I had the same experience after starting a low mileage rebuilt engine that had been in storage.  It ran fine for the first few starts (not driven but just run for about 20-30 min to warm up) when valves began to stick.   It pulled several of the bronze sleeves as pictured in guide #3.    Decided to have it overhauled and mechanic said to use Stabul and Marvel Mystery Oil in both gas and oil while car is in restoration.  Haven't had any problems the last 6 months, but I have concerns using additives.   Any one have opinions on using Marvel Mystery Oil to help the sticking valve issues?  J
By mctim64 - 17 Years Ago
I think Marvel Mysery Oil is great stuff, I have always used it in My Airplane fuel as did my Father before me, there is a major pucker factor when you stick a valve in the air.

Tim

By Ted - 17 Years Ago
Marc (10/11/2008)
I'm close to firing up my new engine, after the car's been sitting for a year. Think I'll drain the tank first. That stuff should burn OK in the lawnmower.

If planning on using that old fuel in your mower, be sure to dilute it heavily with good fuel as the intake valve(s) in that mower engine can stick just as easily as they did in the car.  Ask me how I know.  Much as I hate to do it, I no longer use old gasoline for anything but a fire starter.

By Unibodyguy - 17 Years Ago
I haven't checked this for a few days because of work. Wow! Glad I started this thread. I think Tim/Ted and I don't know this for fact, that possibly the valve guides might have just as you said a liner in them insted of a bronze or cast replacement. That should be something that should be addressed in a valve job or major rebuild. If you going to go through all the trouble to have a engine rebuilt, you might as well do it right. I myself do use Marvel Mystery Oil as a gas additive in my older stuff but not in my daily new cars, and have never had a problem with it, that and Stabil too for long term storage.

                                                                  Michael 

By mctim64 - 17 Years Ago
Stabil I also use in my lawn mower and boat when they get put away for the winter.