Super C specifications and horsepower stuff

I had been told that this thing had like 12hp, but then someone here said that a super A had 18. What are the torque(?) and hp specs on a farmall super c?

Also, my lawn mower has 18hp... Do they measure horsepower differently now than they did in 1951, or is there another more subtle difference? Cuz I know my lawnmower's enging wouldn't move a Super A.

Thanks for any help/theories/thoughts!

The basic formula for horsepower is still the same now as it was 150 years ago when James Watt said 1 horsepower = 33,000 foot / pounds of work in 1 minute. The formula for that when you're measuring something with a flywheel is: HP = (Torque x RPM)/5252 (5252 is a constant produced because the flywheel is a circle and subject to the magic laws of Pi - 3.14 ad infinitum).

The difference between SC and your lawn tractor is the relationship of torque and RPM. Let's assume your SC is HP rated at 23HP at 1500RPM, which your lawnmower is rated at 23HP at 3000RPM.

Do the math in your head - (torque at rated RPM = horsepower x 5252/RPM.) - and you'll find your SC has twice the torque of your lawntractor. Or, more exactly with acutal numbers and a calculator: SC torque = 23*5252/1500rpm = 80 ft. lbs. Versus 18hp lawnmower torque = 18*5252/3000rpm = 31 ft. lbs. of torque.

Actually, the Super C might be a bit higher in RPM than that at rated HP, and the lawnmower might be a little lower in speed, but you get the general idea.

One reason I ask these questions, is a friend and I bought a new 15' rotary hoe from John Deere dealer. As you probably know those are made up on a 4"x4" tool bar with 2 - 3.5' sections and 2 - 4' sections. We wanted to make two hoes for our smaller tractors so we cut the tool bar at the 7-8 foot mark. He took the 3 point equipment for using his 8' hoe behind his 2350 JD In his shop we made up a single point hitch on the 7'for use behind my Farmall 130. At the end of the day I loaded up my 7' hoe and he hitch up his 2350 to the 8'. He headed up a field to see this work, I watched, at soft spot with a bit more incline, the 2350 started to emit black smoke. At the time the 2350 was not that old plus was in the posession of a guy that would do meticulous maintainence. As I drove home that evening, I thought now I've gone and wasted some money on something I cant pull with my 130. To my surprise the 130 has pulled this 7' rotary hoe up hill and down, in 3 gear. Since that I have used the SA with same results. This was 15 years ago so I picked up a 2350 sales info and they only list one hp. I have forgotten exactly how much but 43 hp rings a bell. Now if these guys are using flywheel hp today, that explaines the little difference between JD 2350 and Farmall 130 I'm not saying the 130 has as much hp as the 2350 but they are a lot closer than I expected. Are indeed new tractors being listed on flywheel hp?

Most of the ratings you'll see now are SAE engine horsepower, which is going to be a higher number than PTO horsepower, and doesn't jive with SAE horsepower numbers before about 1970. About that time the SAE allowed testing without accessories, like hydraulic pumps and alternators. They also did tricks like allowing 10W oil in the engine being tested, and maybe without water pumps, but I'd have to look that up to be sure. The latest trick they have in cars was using German PS horsepower, which is slightly inflated versus even present day SAE horsepower - there was a flap recently about Jaguar cars advertising that rating method.

More info -- I was at the local JD dealer to pick up some parts for my 425 lawn tractor and picked up a brochure on the 5x20 series of utility type tractors. They have a 5220 which they rate at 45 PTO (I'm guessing that's a Nebraska result) and 53 engine horsepower (they also rate them in KW to make comparison to Oriental and European tractors rated in Newton Meters or DIN). Anyway, the 5220 with 45PTO HP @2400 = 45*5252/2400rpm = 98 ft/lbs of torque, or only slightly more than Tim's Super C, or my Farmall H. If I compare it to my old JD 60 popper, 38 PTO HP * 5252/900rpm = 221 ft lbs. of torque versus the 5220's 98 ft./lbs. -- which makes me chuckle.

If we paid around 1500 bucks for Tim's Super C versus around $27,000 for a new JD 5220 and saw only 18 ft lbs, or a 20% difference in torque - we'd be pi**sed!! Ha! Another good reason to keep those old tractors running.

BTW, I've got a 10' rotary hoe and use it as what they call a pasture renovator/hole puncher in our clay. I've rigged a hitch to pull it behind the bush hog behind on my JD 60, or the finish mower on my H. Neither one of them seems to notice the difference.

I was operating a new 105 hp Deere last week, nice tractor, smooth shifting, great handling, etc., but no torque. My guess is an 886 with TA would out perform that 105 hp Deere with it's 4 speed power shift. Its not just the new Deeres either, I have driven new CaseIH, FordNH and Kubotas, same thing no torque. The old Farmalls would eat them.

In general I think the problem is this - it's cheaper to make high revving / low torque engines than it is to make slow revving / high torque engines and still keep that magic HP number in the same ballpark so people will buy them. In other words, most people are buying in a way Tim's post indicates, and concentrating on HP numbers.

Long stroke/high torque engines just require heavier parts and more cost in materials - and that's it in a nutshell. If the newer machines didn't have mega choices in gearing, people would be really upset about the kinds of engines being made now.

Just an FYI, here's a link to the Nebraska test site pages. Looks like they're still doing drawbar tests, but I don't see them published very often. Guess there are benefits to living in Nebraska. Also, follow the links to the discussion of the bill in the legislature there to stop funding for Nebraska tests -- and how the tractor dealers say Nebraskans are importing cheap, untested tractors from Iowa. It should be good for a chuckle.

• Nebraska Tests

In fact my opinion sales guys today, be it tractors, cars or trucks do little more than insult you. I once asked a GM dealer to quote me a price for 3 different cars, all with same options. All they could do was pull cards for cars they had on lot. None were equiped exactly same. In frustration the sales manager came out and suggested maybe I couldn't afford the Park Avenue. I quite quickly advised him I didn't come for a lecture on what I could or could not afford. I quite simply wanted to know value I would be getting for money. He did not sell me an automobile, nor will I ever go back for anything.

No. Cylinders: 4 Displ. Cu. In.: 123 No. Speeds: 4F-1R H.P.: 23.7 Approx Shipping Weight (lbs): 2890 Cab: No

Estimated Average Value
Less Repairs Premium $2,190 Good $1,711 Fair $1,131

Approx. Retail Price New: Not Specified

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