Ask the Mechanic
Old-School Valves
READER: I have an old 1939 8N Ford tractor, and I am overhauling the engine. I am relatively new at this engine overhaul game and in need of help with the first thing that I found. The valve lifters have no adjustment for the valves, and the valves are flat on the end next to the lifters. How do I go about adjusting the valves? I see in the manual that the block must be ground to make a new seat for the valves, so I'm guessing I will need to set the new valves.
STEVE: Your tractor has the original valves in it that came from the factory in the early N models. The only way to set these valves is to grind off the end of the valve stem until you have the proper valve clearance between the lifter and the valve. Be sure and measure twice and grind once. The good news is that there are replacement valve lifters that can be adjusted. The new lifter design was an update for this engine. You will also need to replace valves for this conversion. The old "mushroom" valves are rarely seen these days because most engines have been overhauled and updated. The very latest models came with adjustable lifters and rotating valves.
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-- Email Steve Thompson care of askthemechaniccolumn@gmail.com, and be sure to include your contact information and phone number.
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