The Stovebolt Site Forums The Parking Lot Big Bolts 261 Push rods keep popping off!!!

Hi again everyone,
I had the motor running and discovered that a few valves are slow on the return and leaving enough gap for a long enough period of time that the pushrod can (and will) pop out of their seats. I can pretty much count on everytime I start the truck, I will need to remove the valve cover.
The truck sat for many years and due to that fact, I used diesel oil when I changed it. Will the valves loosen up as time goes on, or will I need to replace the guides due to buildup from sitting? Should I put a lighter oil in the motor? Is there a hydraulic lifter kit available for these motors? Any suggestions would be greatly appreciated.

Try some PB Blaster on the valve stems to start with. then after running a while I would hope they begin to free up and all is well.

Did you use SAE 30 weight oil?
Not sure what you should use, but that's what I used. Non detergent if an old engine that probably had it to start with, and normal detergent if rebuilt or known to be clean from the start.

Grigg

I've sprayed them all with Amsoil MP hoping that would do the trick, but they are still slow on the return. Maybe it just needs to run to distribute?
I used Rotella 15w40 diesel motor oil for the initial oil change. I figured due to it's heavier protection it would be easier on the motor during the first few months of bringing her back to life.
As far as I know, the motor has never been rebuilt.
Thanks Grigg

If it's never been rebuilt then it likely was originally run with non detergent oil.

Switching to a detergent oil now has a great chance of breaking loose all sorts of dirt and stuff that was previously causing no harm sticking out of the way to engine parts.

Do you have a full flow oil system, or bypass?

There are a whole bunch of opinions on the subject I'm sure.. I was taught to run non detergent if that's what was originally used, and not risk breaking loose dirt that can cause engine problems. Otherwise if starting from a fresh clean engine then use modern oil (Shell Rotella SAE 30 is a good choice).

Grigg

I've gotten a few engines running that have sat for many years. I would not consider running your engine without getting those sticky valves working. As Grigg has mentioned PB blaster is a choice. I've used Marvel Mystery Oil with good results. Use a oil can that has a small enough spout that you can get between the valve springs and to the stem. Squirt each stem, then turn motor over by hand. You should see which valves are sticking. Take a rubber hammer and when the valve is closed give it a good wrap on the rocker arm. It may take a day or two, but if you keep putting the oil on them and turning it by hand with a gentle wrap or two it will free them up. If after a couple days things are still sticking I'd give in and pull the head.
Good Luck Don

Marvel Mystery oil all over the valves and springs....
Take spark plugs out and use a squirt bottle to spray MMO into combustion chambers. If you can get a socket and breakerbar/ratchet on the crank snout, turn the engine over by hand several times. Do this everyday for a week and it should loosten up. I have had great success with this method.
Hope it helps!

Use Kroil on the valve stems, squirting a liberal amount on them and letting it sit a day or so before starting, then add a little (3 or 4 ounces) to the oil. You'll probably have to bite the bullet and get a valve job done but Kroil would be the only thing I'd consider using to free them up without a complete teardown and guide cleaning with a rotary wire brush.

www.kanolabs.com
Jerry

Thanks for all the replies. I might as well start at the top of the list and go down and we'll see which one works. Considering that I want to move a lot more dirt this summer I really don't want to pull the head if I don't have to.
No one has an idea if there is a hyd. lifter conversion for these motors? I've looked and haven't found one.
Thanks again

What year is your 261? I think that Chevrolet trucks used solid lifters till '59. I may be wrong. I know that the earlier blocks are not drilled for hydraulic lifters.

my cousins gmc stuck valves after he ran it with old gas. gave him a can of kroil and he kept spraying the valve stems without cranking the motor thekroil freed the valves up after time.

It seems like Kroil is the lube of choice. Another question is once I use the Kroil for a week or so, will I need to change the motor oil.
The motor is a 1954 261. I doubted there was a retro fit lifter system, but it was worth asking.
Thanks again for all the responses, and I hope the Kroil works

It won't hurt to run the oil with a little Kroil in it- - - - -other than the possibility it might clean the carbon out from under the piston rings and make it use a little oil. On some older engines, a good thick layer of carbon under the rings is all that's holding them tight against the cylinder walls. Clean it out, the rings shrink away from the cylinders, and you've got an oil burner- - - - -or a mosquito fogger!
Jerry

I don't often read this forum so appologise for the late post. I have a 261 chev engine that was the base engine in a 1960 Canadian Pontiac with hydralic lifters but no oil filter. It seems there are no replacements for the lifters. Gord