Farmall Tractor Sizes

Thu Aug 25, 2005 7:59 am

Could anyone help me out with the sizes of Farmall Tractors?

If I want something a little bigger than the Cub but still a "Classic Farmall", what are my options? I don't mean to get into specifications or anything like that, just a spectrum from little to big would be enough to get me started.

Am I right in assuming the spectrum looks kind of like: Cub, A, Super A, B, C, Super C, H, M, Super M or something like that?

Thu Aug 25, 2005 9:30 am

You are pretty well on track. The A and B were the same engine and driveline with different axle/wheel configurations. The Super A was an improved A. The C was similar to the Super A except in a high wheel, tricycle form. Super C was an improved C. 100 was an improved Super A and the 200 an improved Super C.

The H was the next bigger tractor from the A. It was replaced by the Super H then the 300.

The M was the next size up from the H. It was replaced by the Super M then the 400.

Standard tread tractors of the H size were the 4-series (W-4, O-4, OS-4, I-4). In the M size there was the 6-series. The 9-series was the next larger from the M. There was no 9-series Farmall model. There were some other versions and intermediate models but this covers the big picture.

Thu Aug 25, 2005 11:36 am

When you are down on the 15th I have an A and a C you can look at. If the A starts, which it should, you can even get to drive one.


Thu Aug 25, 2005 12:48 pm

Thanks, Jim, so if I had to diagram it out from small tractors to large, given a little leeway for artistic liberty, it'd be something like:

+ Cub
....+ A, B
....|..+ Super A
....|..|..+ 100
....|..+ C
....|......+ Super C
....|.........+ 200
....+ H
....|..+ Super H
....|..+ 300
....+ M
.......+ Super M
.......+ 400

And so if I was looking for a tractor that was a little larger than the Cub, obviously the A and B tractors would not fit the bill as they used the same
driveline and engine. And I know the M is much too big because a friend has one along with a "Regular"? So I would be looking at something like a Super C? I want something with a wide front axle, not a "tricycle" front end, if you know what I mean...

Cecil - thank you for the offer! It would be awesome to look at some of the other models!

Thu Aug 25, 2005 4:01 pm

The "A", "B", and "C" used the same engine, but not the same engine as a Cub. They are the next size up. A ,B, & C had a 113 cubic inch engine, Cub only had 60 cubic inches. Some "C's" & the Super C had a 123 CI engine.

Thu Aug 25, 2005 4:05 pm

I guess I wasn't clear on one point. The A and B used the same drive train as each other, but not the same as the Cub. The A is about 50% larger than a Cub with close to twice the power.

Of the models mentioned, the Cub, A, Super A and 100 are all offset designs and came with a wide front axle. The other models were all tricycle type with a wide front axle available as an option.

Fri Aug 26, 2005 8:37 am

I can't help but snicker a little when I hear people brag on how much work a Cub can do......Nothing against a Cub as they have their place but a super A will probably do two-three times what a Cub will and it's only 1/3 bigger in physical size!


Fri Aug 26, 2005 4:41 pm

Super A- You got a good point. The Cub has a leg up on other tractors in that is has live hydraulics and a hitch system. Most A's I've seen are pretty bare bones but make great mowers with the woods underneath.

I've got a Allis Chalmers CA and that has 3x's the CUB power in in a package just slightly larger with hyd. and a hitch. So go figure.

Fri Aug 26, 2005 4:45 pm

The Super A typically has Touch Control (2 valve vs. 1 on a Cub) and the hitch system is essentially the same (except bigger) as a Cub of the corresponding year.

Fri Aug 26, 2005 7:52 pm

Jim, I called a friend of mine tonight and he has an A ( no hyd.). Was it only the 113" motor that didn't have hyd.? Obviously the 123 on the Super was the same setup as the C and Super C.

Fri Aug 26, 2005 9:22 pm

No the Super A had a 113 engine. All you have to do is put in thinwall sleeves and bigger pistons to make it a 123. Externally, you can't tell the difference between the two.


Fri Aug 26, 2005 10:17 pm

OK then, What was the diff between an A and a Super A if the engines were the same?

Fri Aug 26, 2005 11:43 pm

WKPoor wrote:OK then, What was the diff between an A and a Super A if the engines were the same?

Basicly, everything else.

The Super had Touch-Control (technicly an option but . . .). Allowance for the hydraulics required every major casting from the fan to the steering wheel to change. The final drives were changed for the quick attach implement mounts. Some internal changes to the transmission. An A engine block can't be used in a Super A because it lacks the mounting point for the hydraulic pump.

The engine blocks were changed in '51 to a bigger bottom bore to allow for the 123" sleeves. From that point, the Super A used thicker sleeves to maintain the 113" size. The 123 size was used in a few Cs, all Super Cs and the Super A1.

Sat Aug 27, 2005 12:03 am

I think I had better stick to H's and M's. The whole A, B, BN , Super A, Super C, thing has got me all flustered. LOLOLOL :lol: :lol:

Hey Allenlook, what you got against narrow front? Its like having ZTR. I was all hep to putting wide front on the H until I realized I didn't what to give up the menuverability.

Sizes Engines and Pistons

Sun Aug 28, 2005 10:26 pm

The A's, C's, Super A's, and Super C's used the same basic blocks there were several differences though between them other than the transmissions and treads

The Only Difference between an A and a C is that a C uses a high compression piston, the pistons from a C will go into an A and give it a HP boost, this is what many tractor pullers do to make them run stronger

The only difference between a Super A and a Super C is the same, the pistons are different. The pistons for a Super A and an A are identical and The Pistons for a C and a Super C are identical

a B Uses a the Same Block as well just Different configurations from the A maybe slightly better Pistons as well

The Difference between the 'normal' letter series and the super letter series is the supers have waterpumps.

The H's and The M's and The Super H's And Super M's are the same way, the only differences between letters are pistons and a waterpump makes it a Super Letter Series

The H's and The M's Used A Larger Block (123 Cu In.) While The A's and C's and B's Used A Smaller Block (113 Cu In.)

Believe me on this I made a Pulling Tractor for a friend of mine out of his old Super A by putting Super C pistons into it, seamless transition, it'll purr along with 3 16" plows now.