C221 cylinder head

[JAsher452x]

I'm planning on reworking my cylinder head on my 606 this summer. Compression across the cylinders is 150 psi +-2, problem is leaking oil in the valve guides. going to do a complete rebuild of the head and cut the new guides for Vinton seals. My I&T manual gives me all the specs for the head except valve protrusion, does anyone have that spec?

 

[rustred]

these old tractors never had valve seals and don't require them. it requires some oil to get in the guides for lubrication. other wise you will get guide wear. presume you are installing new seats and valves as necessary. can pretty well tell protrusion by looking at the valve. has to be higher than the combustion chamber by about 1/16 " if the valve face is flat or recessed will needs seats and valves once the margin gets thin.

 

[JAsher452x]

thanks for the info. I'm used to the specs of Detroit and Cummins with everything being measured out. When I checked the valves last year I noticed that it had o-ring style seals on the valves. Manual shows the early ones had no seals, then only intakes, and then finally all had seals. pretty sure guides and stems are worn past service life.

 

[MikeJM]

There are 4 types of valve seals
None
O-ring in a groove right below the retainer to keep excess oil from running right down the stem.
Umbrella, which is exactly as it sounds, keeps the oil from running right down the stem to the guide.
Positive type, seals the guide to the valve stem and meters oil to lubricate the stem.

Chances are it ll need guides, valves and seats. Most everyone I ve done recently has been done so many times they need it all. One had over .012" clearance on the exhaust guides and was pushing soot up the guide.

Valve protrusion is not as critical on a gas engine as it is on diesel where too much and they hit pistons or too low and it effects compression. But you don t want the valves sunk too low because it will effect flow and the rocker arm geometry.