[SEL] making valve guides

[John Hall]

I need some help/opinions. I am restoring a Titan 10-20 tractor. Those who 
are familiar with these know that the engine is pretty close to being a 2 
cylinder T&G stationary engine. I have one valve guide that is broke and the 
others have bad wear. I am going to make new ones out of cast iron. How much 
clearance do I need? The guides are 5 inches long and the valve stems are 
1/2" dia. The only oil comes from an occasional squirt in an oil cup.

John Hall
jthall at worldnet.att.net