I have a 1955 Ford F100 and it has a Ford 312 engine. The Y block dropped two push rods. The number 3 intake and the number 8 exhaust. I took it all apart and put the push rods back in contact with the lifters. I adjusted the valves again and found the number 3 intake spring compress and then slams back shut. The push rod seems straight. Also I observed that the lifter does go up and down in its bore. Any ideas?

thanks
Jerry

 

 

The Y block is known for valve oiling issues. Oiling issues make for sticky and non performing valves. A valve should close when it is not held open. A bit better description of what is happening might help diagnose the issue. Has this engine been in regular service or has it been in storage of some kind?

Agree, the mention of Chevy is a bit confusing in your post.

 

Sorry for the confusion. My truck has been sitting in my garage for a while and i decided to get it running. It is a 312 y block with zero miles. I started it up and it ran fine. But then it started to miss. So I did a compression check and found cylinder 8 with no compression. i pulled the valve cover off and found the push rod on the exhaust was not connected to the rocker arm. I tried to fish it out but I could not. So I took off the intake and the valley pan off and found out the push rod was not engaged with the lifter. And then I saw the push rod for the intake on number 3 cylinder was not connected to the rocker arm. So i put the motor at tdc and proceeded to adjust the valves. After adjusting the valves I noticed that the valve spring on the number 3 cylinder was compressed and the push rod was detached from the rocker arm. I turned the motor another 45 degrees and I heard a pop and the intake spring popped back up.
I have read that 312 y blocks have valve train problems. I am trying to see if its worth it to fix my y block. Or cut my losses and switch to a small block Chevy? I would like to use what I have. The truck is just going to be a daily driver once its done. Thanks for all the advice. Sorry for confusing everyone.

Jerry

 

I have nothing against engine swaps and mixing and matching manufacturers. Heck, I'm running Cadillac power in my 49. I also own a factory mix-n-match vehicle; a 67 Jeepster Commando with was manufactured by Kaiser with a Buick engine...woohoo.
There are so many great engine choices out there, why immediately go small block Chevy?

I think the "Y" blocks are great engines. I vote for keeping it

Bobby

 

If this is a vote, I vote for the Chevy motor, but I am a Chevy guy with a heart for these old Ford trucks. Of course my truck has gone total dark side as well, lol

 

You had a valve stuck in #8 cylinder. When the rocker was no longer holding the valve open, the spring closed it. Normal. However, the valve is sticking and until it gets lubrication to the stem it will most likely do the same thing, Work lubrication around all the stems, this one in particular, and work the valve manually. They make tools to compress valves. You said it had zero miles which indicates it was a fresh rebuild or new engine when it was garaged. If that is a freshly rebuilt 312 Y block, don't even think about swapping it out. Show it some attention and enjoy it.
JMHO.
Edit: Free that valve and start the engine with the valve covers off. Make sure you are getting oil to those rocker shafts.

 

I drive old Chevys. I am just trying to figure out my best options. If I stick to the y block I have to take off the cylinder head and get it checked. I am just trying build a cheap reliable truck. Valve train problems dont make for a reliable truck.

Thanks

Jerry

 

Yea, if its been sitting for a while that valve stem has gotten sticky. Spray the stem with brake cleaner or car cleaner while tapping on the valve until it frees up a bit. Then put it back together, maybe add some ATF or Marvel Mystery Oil to the crankcase and see what happens.

I just recently had an old John Deere bend a pushrod due to a sticky valve (that tractor had sat for about 20 years) I straightened out the pushrod, freed up the valve and its running great.

Bobby

 

YES in a heartbeat

 

I will put some marvel oil on the number 3 cylinder intake. probably over the course of the next two weeks. Then turn it by hand to get the oil in it. Just really a pisser.

Thanks

Jerry

 

I hear ya. Sometimes owning an old truck is like stepping on your own *****....LOL

Good luck with it
Bobby

 

Old Chevy Classics

 

If a chevy is what you have than use it. This hobby of building these vehicles is expensive enough without setting a perfectly good motor on the sidelines because it does not match the original make. The darkside is not as dark as some would suggest.

 

As a teenager, I had a ’56 Ford Custom Line that I put a 292 engine into (replaced a bad 272). I was constantly working on it; main issues were valve train and rear main seal oil issues. Unless you are trying to maintain the stock vintage, my vote goes to the Chevy engine. In fact, I recently put a new 430hp 383 create engine into my ’56 Big Window. Low-end torque is outstanding.

Good luck with whatever decision you make.