H ground speed

Can someone tell me what the ground speed would be in first and second gear at PTO rpm? Thanks for any assistance. Tom/Idaho

Depends on tire size, with 11.2-38 speeds are 2.5, 3.375, 4.125, 5.125, 15.625. Slightly faster with 12.4-38. This is at the full load speed of engine 1650 rpm, which should correspond to approximatly 540 pto rpm.

Thanks for your assistance. Tom/Idaho

Just to confuse things a bit, I guess, here are the speeds listed in an old IHC sales brochure called The Farmall System of Farming, Farmalls H and M. By the looks of the tractors, I'd guess this was printed about 1941. IHC was always cagey about dating this stuff.Tires for H were listed as 5.50-16 front and 10-38 rear. Ground speeds were 2-5/8, 3-1/2, 4-1/4, 5-3/8 and 15-5/8. The brochure uses fractions, not decimals, so I give these numbers here. I'm too busy or too lazy right now to get out a calculator and go to decimal speeds. There are no notes about engine speed, but my understanding is that it was normal to give ground speeds at full-load governed RPM, which in the case of the H was 1650. Naturally, at high-idle RPM, the ground speeds would go up proportionally. I don't have the high-idle speed at hand, but I think it was in the low 1800s. Perhaps somebody else can supply that number. I used to like to play armchair engineer and calculate things like this. As one of the other notes here says, the tire size would make a difference. I always thought the H on rubber had a 4th gear that just wasn't fast enough for hauling on the road, and that 5th gear was pretty useless for hauling on rough country roads because there wasn't enough torque at idle. The brochure gives "High speed" as 9-1/2 to 15-5/8 mph, which suggests that 9-1/2 was about as slow as the tractor would pull any kind of a load. That was much too fast for the old steel-tired wagons I grew up with. The 7-mph 4th gear option would have been great, because even throttled back just a bit, you'd have had a good ground speed, with a little less noise. I remember driving loads of hay about a mile over a washboard road, with the tractor roaring away and doing somewhere between 5 and 6 mph.

My guess would be that the 5 3/8 4th gear speed is a misprint, but they agree with the ones in Guy Fay's data book. The ones I quoted were from the latest H Operator's manual, and are the same as those in my dad's 47 H operators manual, I'm sure of the 5 1/8, I think the 47 manual had 4 1/8 for 3rd and 2 3/8 for second. I probably spent 5000 hours on that H. I would think that the published numbers in the manuals would be more accurate than the advertising, but anyway, it is a minor point. My dad also had a prewar H, probably a 40 or 41 delivered on steel, that manual said the speed was on 51 inch steel wheels -- I wish I would have kept those manuals.

Just a little added note to all the above info.... "Back then" we had a '50 H with the 7 mph 4th gear and that was a very useful gear, but it would have been so nice to have had the lower speed 4th gear too. Many, many regular 4th gear jobs just couldn't be done in 4th with the H with 7 mph speed because there just wasn't enough torque in the engine to pull much if you slowed down to 4 1/2-5 1/2 mph.....When you were planting corn, drilling small grain or cultivating for instance. 3rd gear was still too slow to make up for the missing 5 1/8 mph 4th gear. But for sure the high speed 4th was great for pulling heavy loads on the road when 5th was just too fast or the tractor didn't have enough power to pull the load or "just chugging" around the lanes and fields. The "perfect H" was the Super H with it's better speeds in every gear and the extra 5-6 horsepower, Then the 300 was even better with it's live hydraulics and continous running PTO.

Even MORE perfect would have been six speeds, like John Deere and Oliver 70 had not too long after rubber tires started coming from the factories.