Carbon Buildup and Stuck Valves

[TJ's GMC]

So all the oil companies that recommend zinc for engines are wrong just because You think zinc is not needed? Funny. And 5-50 is not the GM spec for these V6's by the way. I don't care how many engines you've rebuilt. lol Just cause you can rebuild an engine doesn't mean you know them!

[br-549]

We have the bus home now. It ran great the 300+ miles home. Now to answer a few questions. The valve was stuck at start-up on the morning of second day of out trip. I pulled plug wires until i knew the cyl that was missing. I then pulled the plug and watched it fire. Then i checked for compression and it was good so i pulled the valve cover and the valve was stuck in the down position. I tapped it with a brass hammer but it would not return. I then gently used a crows foot in the spring and could push it up but with each revolution it would stick. I ran blaster down the stem but that did not help. So- i was able to hook up with a friend of a friend about 10 miles away you owned a place we could park the bus and work. I removed the push rod on the affected valve and slowly drove it the 10 miles. We removed the cyl head cleaned all the chambers and parts, checked all the valves and push rods for warp. A gasket set was not available so we reused the head gasket and made new intake gaskets.

Now, when the bus was brought out of storage- the oil and filter where changes- plugs replaced- points- cond- cap- rotor- wires- fuel filters (3) where replace- fuel tanks where drained but not flushed. I think that is where i missed the boat. I did change the last in line fuel filter the 2nd time after driving the 1st 100 miles but this afternoon i checked the clear filter and it looks dark. It will be a major job to remove these fuel tanks. I think i will try to flush them first and see what i get out of them.

I believe i can get a steam jenny wand down the filler neck and steam the tanks- what are your thought on this? Thanks for all the help! ja

[Charon]

My goodness child! Go look at the shear. Pressure ratings. All the specs on oil from 1960. Then compare to today's oil. No comparison. Sadly I think I just found kindergarten again.

[Charon]

You can feel the varnish in old gasoline. Stick your fingers in. And wait till it dries. Then touch your fingers together. You will feel a very slight stickiness. When you pull apart. Last year I had a guy stick 4 intake valves on a flat head v8 Ford. I doubt the system had 4 ounces of very goopy tar in the tank. It does not take much.

[Charon]

Also. Just so People know. You won't stick exhaust valves with bad gasoline. Only intake valves. And the tighter the engine the more prone it is. When an old tractor gets rebuilt. I ALWAYS go one size over when I ream the guides. That builds on a lot of protection from bad gasoline the farmers are famous for using.

[TJ's GMC]

Originally Posted by Charon

My goodness child! Go look at the shear. Pressure ratings. All the specs on oil from 1960. Then compare to today's oil. No comparison. Sadly I think I just found kindergarten again.

Uh huh. Like I had mentioned already....zinc was added for a reason. And now taken away again because new engines have roller cams and rockers. But you didn't answer my question as to why oil companies like Amsoil for instance recommend zinc oil for flat tappet engines. It's still them against yourself.

[Charon]

Do some research child!

[Charon]

Talk with your rep.

[TJ's GMC]

Originally Posted by Charon

Do some research child!

I have old man. lol

[Charon]

Your a clown. And I am done child.