1945 B Valve Adjustments

[James Tabor]

Just put the COMPLETELY rebuilt head back on my 45 B. Adjusted valves .020 like the book said. Ran it for a while, let it cool down, pulled the valve cover back off. Seems to be oiling properly and rechecked the valve clearance. Had to readjust two. I have always been told by the "Old Timers" that one should be able to hear the valves/rods clacking because as the push rods heat up the clearance deminishes and the extra space is needed to avoid warping said rods. My runs like a top but you can hear them clacking 50 feet away. The JD shop manual advises that valves should be adjusted at .020 unless substantial wear is suspected then you should loosen the rockers until slight resistance is felt when turning the push rods then back off 1/3 of a turn and tighten. I do not detect any wear. Question: How loud should they be?

 

[Anonymous-0]

Did you resurface the radius on the rocker arms? Set both valves while that cylinder is @ TDC compression stroke?

 

[PBrowning]

James -- Deere service techs found that by using a room temperature tappet setting at 0.002 over the specified 0.020 -- they ended up at 0.020 when hot. So --- at room temp, set them at 0.022-inch.

Look also at the tappet levers for a wear pattern I call "cupping". If the lever part that meets the valve stem is worn like that, you aren't able to achieve a reliable setting. Such levers can be saved, and must be machined to present a smooth, flat, but slightly convex surface to the stem.

Write me if you are still in the dark -- I will send you some data excerpted from one of the "good books". (PatB)