M Farmall

[Mark Steinmann]

Hello, i am rebuilding an M, i want to take the liners out and replace with a bigger piston, can you tell me where to find a piston that will fit without the liners,

 

[glennster]

m has 3 7/8 inch bore, the super m and 400 have 4 " bore. not sure on the 450 but you could have a machine shop bore the m block to accept the bigger pistons, there should be enough meat in the cylinder walls to go a little ways anyway. some of the pullers do that. butt.....if you cook a piston, or its its time for a major....you may junk the block. the m can be bored to accept the super m sleeves, which is a viable alternative. is there a reason you want to run directly in the bores without a sleeve??

 

[eric wi]

i don't know what piston would work but if u run without liner u will have to bore out the fire ring off the liner but it will not that much power than running 450 sleve and piston set it make it 4 1/8 if want more power u are better off putting a stroker crank in it

 

[Andy Martin]

You don't have to bore the block to run SM pistons, they sell a thinner sleeve for that.

 

[georgeky]

You can go to 4 inch pistons, making the M equal to the SM/400 at 264 CI. Those kits are sold everywhere including here at YT. To go any bigger machine work will have to be done. Folks(mostly pullers) do run some of them sleevless with larger pistons, but I do NOT recommend it, as it severely limits the life of the engine. The sleeve system is the best thing ever put in an engine. It can be rebuilt forever if it doesn't freeze and bust.

 

[dej(Jed)]

We ran Chevy 4.25" pistons in the block on one.
Pulled great for a while.