There’s something beautiful about a perfectly restored Ford 8N tractor – but there’s a big soft spot in my heart for a V8 conversion job! It’s one of my favorite custom projects that we’ve done in the shop. Here’s a quick walk-through of conversion kits and the basic steps you’d need to take to muscle up your own Ford 8N tractor. With a proper conversion, you can get an 8N tractor up to 100 horsepower!
You’ll find tractors on the market today that were converted to a V8 using a kit produced by Funk Manufacturing (which was primarily in the aviation business, aka Funk Aviation or Funk Aircraft) of Coffeyville, Kansas. Dealers sometimes bought the kits and converted new tractors themselves, while others were purchased by farmers who already owned an N and wanted to increase their tractor’s power. Funk marketed these kits directly to farmers – my favorite slogan from their literature is “A Husky Beauty with Power to Spare!”
These conversion kits were in high demand in the late 40s and early 50s as farmers began to demand more horsepower. The introduction of the 8N wasn’t enough for farmers who wanted to use a 3-bottom plow. Ford couldn’t supply more power fast enough, so these conversion kits became popular. A fire in the Funk factory destroyed many records, so we’re unsure just how many conversion kits were produced. While I’m writing specifically about V8 conversions, Funk also made 6-cylinder conversion kits. Eventually, the blossoming popularity of these kits and the demand from the farmers lead to the Golden Jubilee tractor, which spelled the end of the conversion kits.
While other manufacturing companies have made (and continue to make) conversion kits, the Funk Conversion is probably the most common. Sometimes people will refer to any V8 conversion as a “Funk Conversion,” but a true Funk-manufactured conversion kit has some telltale signs, like a cast iron oil pan, a bump in the hood near the dash, and notable raised and extended hood. Funk kits are no longer in manufacture, but can sometimes be found at auction sales.
You don’t need a special kit to do a conversion, though – in fact, it can be a lot of fun to strike out on your own! With some solid fabrication skills (and access to a machine shop), you can muscle up your own N-series tractor.
There are a lot of things to take into consideration in doing your own conversion. Here’s a list (that doesn’t include everything!) to get you started.
- Choose a flat head engine (without a cast iron bellhousing).
- You’ll have to stretch the entire tractor to accommodate the longer engine – including the radius arms, steering components, and the hood.
- The radiator will need two water inlets and outlets. Overheating is a common problem with these conversions. I recommend using a radiator from a 9N with a bigger tank on top, cutting two holes in it so that both water pumps from the flat head engine are operable.
- Get creative with the gas tank. You can either make it smaller to fit under the hood, or put it somewhere else – the fenders, behind the back seat, longways inside the hood, etc.
- Anything goes with the carburetor! I’ve seen successful conversions with a tri-power, dual quads, or a single carburetor.
- Offenhauser or Edelbrock aluminum heads are popular, but this is another area where you can have some fun and get creative.
- Exhaust can be a challenge, but it’s worth figuring out how to make a dual exhaust. Many companies offer kits that you can use.
- You’ll need to make your own adapter plate.
- The original ignition can work if you wire it into a modern distributor, or you can replace the entire system.
- The flywheel and clutch can be one of the biggest challenges to a do-it-yourself approach. The original clutch is too big to fit into the tractor bell housing. We’ve tried out a few different solutions in the shop with our conversion jobs. One time we used a Ford 600 (tractor) clutch plate with a flathead V8 car pressure plate – a shorter one can fit in the bell housing. The clutch was slightly smaller than the original one, but it still worked.
- The other really challenging part is the starter. Most people will use a flathead starter to match the flathead’s ring gear and flywheel.
How about you – have you ever completed a V8 conversion? Share your best tips below in the comments.