Everybody wants more power out of their tractor, right? I’ll share my best tips for increasing the HP on your Farmall M.
The following are some affordable ways to gain more HP:
- Install a power valve inside the carburetor. Consider using a power valve from either a Farmall 400 or 450 to make your carburetor larger jetted. A power valve can be purchased at your local CaseIH dealership.
- Increase your compression ratio by installing a set of pop-up pistons. If you are mechanically inclined, you could easily install a pop-up piston kit on your own.
- Increase your bore from 3 7/8” to 4 1/8” (if you choose to install pop-up pistons you could do both step number 2 and 3 at the same time).
- Make sure your tractor has a good head, and consider upgrading it. The best head is an LP Gas head. They have bigger valves which gives higher compression and better flow resulting in a significant improvement. However, they are expensive. If you can’t afford an LP gas head, at least make sure you have a gas head instead of a kerosene head. If your tractor serial number ends with X1, you likely have a gas head (unless it’s been changed through the years). If your tag ends with X3, you likely have a kerosene head. If you discover a kerosene head on your tractor, remove it, and replace it with a gas head (good) or LP gas head (best).
- Install a better camshaft, like one made by Denny’s Carb Shack or Iseki.
- Obtain better fuel flow by installing a LP Gas intake and exhaust manifold. The manifold easily attaches onto the block with the same bolts and holes.
- Install a rocket governor. You may be able to find a used original governor made by M&W, but if you can’t, several places are making and selling new high performance governors.
If you have deep pockets, try these upgrades for a more significant HP gain:
- Increase the stroke with a custom crank and rods. This is expensive, but if you’re serious about tractor pulling and want to win every time, it may be necessary.
- Install roller rockers! A set of new rockers will change the duration of how fast the rockers open and close–which enables your engine to move more gas in and out.
The Farmall M at my house has M&W power pistons, a M&W rocket governor, improved camshaft, 450 carburetor jets and a LP-gas intake and exhaust manifold. With these affordable upgrades, the tractor is somewhat competitive in the 5500+ pound class and has brought home several trophies. While competing is fun, building the tractor is the best part for me. Have fun making these improvements to your Farmall M tractor!