How To Eyeball Piston ring Size

[photoman63]

Good day to all you red tractor folks,
My father-in-law is passing down one of his many farmalls to his daughter, (my wife) But I am the one who will be rebuilding the motor. He says it smokes a little, and just needs a ring job. I have rebuilt a motor once, about 30 years ago, I think I can do it. I just need help knowing what sized piston rings to get. As far as I know, the motor is all original, and never been cracked open. With that being said, the father-in-law said going one size over should do the trick. Any thoughts or help in this matter would help me out allot.
Thanks in advance.
May the sun be at your back, and the grass discharge be down wind

[outdoors4evr]

Measure it. Don't guess.

[ricky racer]

Measure it. Don't guess.

[Eugene]

The father-in-law said going one size over should do the trick.

There is a good chance that the engine has been overhauled at least once and may or may not be "standard". One problem is that replacement sleeve and piston kits have a slightly larger bore than the factory standard.

I'm assuming one size over means ring size. You need to check the ring end gap before installing rings on the piston.

If you are going to do a ring job, might as well replace the rod and main bearings, and lap the valves.

As previously stated, measure. Measure before purchasing any parts.

[Eugene]

The father-in-law said going one size over should do the trick.

There is a good chance that the engine has been overhauled at least once and may or may not be "standard". One problem is that replacement sleeve and piston kits have a slightly larger bore than the factory standard.

I'm assuming one size over means ring size. You need to check the ring end gap before installing rings on the piston.

If you are going to do a ring job, might as well replace the rod and main bearings, and lap the valves.

As previously stated, measure. Measure before purchasing any parts.

Edit: You didn't indicate which model Farmall tractor you have. There are parts and service manuals for your tractor. On line advertisers for tractor parts frequently have free catalogs. The free catalogs frequently list parts by model number and sometimes tractor serial number.

[photoman63]

Thanks for the posts, and yes! I will measure the cylinders for proper piston ring size. I want to do out right. It is a farmall H. Not sure the year yet. The engine hasn't been ran in several years now. are there steps I should follow before just cranking her up? I plan on cleaning fuel tank, and pulling sparkplugs and just spinning crank shafts to make sure it moves freely. I think I should try and get it running before to take it apart for the ring swap. any thoughts, of things I should check?

[Matt Kirsch]

A re-ring job is not the way to go if you want to do it right. It isn't always effective at doing what you want it to do, which is restore compression and stop the smoking. Then you've wasted your time and money and have to do it all over again with a full rebuild.

Look up a show called "Gearz" on the web. The host has done multiple episodes on bringing old engines back from the dead, if you can get past his annoying demeanor. Basically you change the oil, do an ignition tuneup, rebuild the carburetor, fix the wiring, add fuel and a battery, and go.