Farmall M overhaul

[Central Illinois]

I am doing a major overhaul on a late 1949 Farmall M. I ordered the complete kit through Yesterday's Tractor. They can not get me the recommended ring gap. I have read that .003-.004 per inch of bore is a good rule of thumb. I am trying to find what is recommended for the piston to cylinder clearance. For some reason .004 is on my mind but I don't know if that is correct? Just going by feel the pistons without the rings slide in but I would feel better if I could get a measurement. Thanks.

 

[the tractor vet]

Well the proper way is witha Ribbon feeler gauge and a spring scale , Now off the top of my head with out running out to the truck and digging thru the books i can not give you the exact thickness qauge or pounds of pull . Myself i don't do that i mike the pistons and the cylinders once the sleeves are stuff in and set then i FIT each piston to the hole looking for between .004 to .0045 , then i am happy . Not all pistons are the same size and not all sleeves are the same inside or outside . massure massure everything .

 

[Central Illinois]

I should have put my cheaters on earlier so I could see the manual better. I found what the IH manual says. Skirt clearance on sleeve. .0055-.0065. A 1/2 wide ribbon gauge may be used as a Go gauge with a light pull of 2 to 4 pounds. A .006 ribbon may be used as a No Go gauge with a tight pull of 11 to 14 pounds. It also has a side note that says because of material shortage during war years, many engines were equipped with grey iron pistons fitted in sleeves with a measuring clearance of .0045-.0055. It also says the ring end gap should be .010-.020. I like your way better. I think it would be a more accurate reading.