Farmall H Horsepower upgrades

[Cdog2cool4u]

As I was browsing the internet tonight, I came upon this article that caught my eye. To quickly summarize it suggests you could gain power in a H by simply swapping in the carburetor and intake manifold from a 300. At this point I'd input Tim "The Tool Man" Taylor grunts. I'm curious if any of you have tried it and or maybe have quantifiable or qualitative results of a difference. Assuming everything would line up it seems like an interesting/simple concept with minimal headache to implement. I've also inserted in the original articles link for reference/credit. Look forward to hearing y'alls thoughts and opinions.

https://antiquetractorblog.com/2016/05/23/how-to-get-more-hp-from-your-farmall-h-tractor/

This post was edited by Cdog2cool4u on 12/14/2023 at 05:21 am.

 

[fastfarmall]

They didn't say how much ,my opinion is that its so little,it would be to be hard to measure it,the amount of humidity in the air will make a difference also. 1 horsepower more isn't going to do nothing for the guy pulling a 7 foot mower,or a hay rake,if you put in fire craters pistons your only going to get 3.9 more horse power I think it was!! Could it be Steiner is over stocked with manifold's, and there not moving!!

 

[caterpillar guy]

If you want more power just buy an M and sell the H. Never messed with all that nonsense. I have also never had a tractor to big.

 

[Cdog2cool4u]

(quoted from post at 06:49:38 12/14/23) They didn't say how much ,my opinion is that its so little,it would be to be hard to measure it,the amount of humidity in the air will make a difference also. 1 horsepower more isn't going to do nothing for the guy pulling a 7 foot mower,or a hay rake,if you put in fire craters pistons your only going to get 3.9 more horse power I think it was!! Could it be Steiner is over stocked with manifold's, and there not moving!!

I suspect their reasoning/thought process is bigger carb and a bigger manifold would allow more fuel and air thus more power. But I could be wrong, and I also don't have these "upgraded parts" or the stock parts at hand to be able to measure them for comparison. I wouldn't put it past someone to have done these "upgrades" and or others and put their tractor on a dyno just because they had the ability to do so.

 

[Cdog2cool4u]

I can't argue with the logic in buying the tractor originally designed with the power to do the job you're trying to accomplish. And I'm sure it's possible with the right amount of effort, research, and especially money to make an H have the same horsepower as a stock M. I'm not about to go find a 300 carb and intake based off the article to gain an undetermined/ possibly indiscernible gain of a horse and a half. But if you could show me testing results or some one had personnel experience that this minor change would bridge a significant part of the gap between an H and a Super H that could be tempting to consider.

This post was edited by Cdog2cool4u on 12/14/2023 at 05:19 am.

 

[BarnyardEngineering]

Unfortunately we're not going to be able to show you anything like that. Most of the folks here are farmers and lack the desire and scientific equipment to do such testing.

Best you're going to find is the Nebraska tests for the H, Super H, 300, and 350. They're linked over on tractordata. The information isn't exactly what you're looking for because each tractor got a small increase in displacement but it's really all there is.

It really doesn't take much to get stock M horsepower out of an H, and I'd dare say that most every H has been there at some point in its life. When the engine was overhauled they would get overbore kits, step-headed pistons, block and head surfaces shaved... all with the stock carburetor. IH left a lot on the table with the letter series tractors.

 

[rustyfarmall]

The manifold and carburetor from a 300 is the same as used on a Super H. The Super H engine had 164 cubic inches, versus 152 cubic inches for the standard H. The larger engine required a larger carburetor. THAT is where the extra horsepower comes from.

The 300 carburetor will do nothing for an H unless the engine is modified.

 

[DeltaRed]

Ditto.

 

[560Dennis]

Check with Wilson , for size I called Edelbrock,but they are phasing out of nos , I havent pursued it .Wilson system ,

 

[D Slater]

Comparing tractors that were tested at Nebraska for gasoline. H showed a max belt HP of 24.28. SH showed 31.3 for same test. SH used aluminum pistons with 1/8 bigger bore, slightly more compression and combustion chamber was slightly redesigned. Different camshaft and carburetor used looked like a SM but with smaller venturi and different fuel metering. Also the throttle shaft and housing from governor to carburetor was shortened slightly. Don't know if it had any effect, but air cleaner outlet and pipe to carburetor was bigger diameter than a H. Drawbar HP is harder to compare as the H was tested on 36 inch rubber and SH on 38 inch. If the H gasoline has 3-7/16 bore P&S installed with more compression with a 300 carburetor and manifold installed it should fall between the two HP at high RPM but may fall off when engine starts lugging down. Turning RPM up a little would gain some. 300 and 350 gas carburetors have a bigger venturi than a SH used to pass more air and fuel mix into engine. Instead of spending money on your engine probably the most cost effective thing is to find a 300 or 350 engine, build to 175 cubic inch or a running one. Gain at least 10 to 12 HP.

 

[redforlife]

I'm not gonna to say it wouldn't add
something to the horse power. But I think
it's fair to say that it would go un-
noticed unless the cylinder bore was made
equivelant to a Super H or 300. Then you'd
get some 'noticeable' horse power
improvement.

 

[Janicholson]

That engine, with aluminum pistons and the new manifold/carb could be twisted to 2100rpm and utilize rpm as a displacement factor. Jim

 

[the tractor vet]

Your spitting in the wind here , ya want more pony's out of a plain jane H then dig into the piggy bank , you will need higher compression pistons bigger intakes THEN the carb an manifold along with a lumptie stick to open the valves wider and hold them open LONGER along with some gov work to gain 500 rpm and a balance job , And for all that ya may gain 10-15 extra ponys . Or ya could pull the sleeves put the boring bar to it and stuff in 806 gas pistons with some work along with the rest of what i said , Now ya will also need a 450 carb to feed it . Here again how deep is the Piggy bank .

 

[DeltaRed]

A 350(175 ci) is rated at 40 horse.A 350 is basicly an H on steriods. An early M (248ci) is rated about 36. However,an M willeasily out pull that 350. I have both...

 

[ss55]

I think the IH 350 utility ran at 2000 PRM for more HP than the same 175 CID engine in a Farmall 350 that ran at 1750 RPM. Your H originally had a 152 CID engine running at 1650 RPM, although by now most have larger diameter Super H pistons for 164 CID. Check the Nebraska Tractor tests to be sure. A 65 year old tractor could probably benefit from some some distributor re-tuning and camshaft regrind anyway. Maybe your tractor can be setup to 350 specs? Note: higher engine RPM will also increase the PTO RPM.

 

[the tractor vet]

To the best of what i know about them they have a;ways been aluim. pistons then came the step heads to reach up into the head to increase compression . thus gaining around 7-10% . The h replaced two horses and waa sold as a 50 to 100 acre main tractor as i recall. Pulled a 2 bottom 14 inch plow and like the M starting with plowing as soon as chores were done it would work till noon on a tank of fuel and need to take a,lunch break. . The old 1951 M that was under the picker would work from 8 in the morning and at around noon Ya had best be on the head land when it told ya it was lunch time and take a break and go fetch four five gallon cans of gas and it would work till around five and need fed again .

 

[D Slater]

Think all IH offered was grey or cast iron pistons into 1952 for H and M. Then on some they still offered both for a while. Some SM were equipped with grey iron pistons and had K on serial to ID. In 52 IH offered a power improvement package for C-248 engines that contained 3-7/8 aluminum pistons, carburetor metering parts and the latest gas manifold at the time.

 

[Butch(OH)]

Not many people know it but there was a service camshaft offered for the H that added HP We had a 40 that had most of the M&W goodies, pistons, live PTO, hydraulic pump etc. Plus much taken off the head. We pulled it some and the dealer got involved because we live in JD land. They had the tractor and dynoed it at 38HP. Somebody saw the cam in the parts books so they ordered and installed the service cam. Tractor was very close to 41 HP. Tractor won its class at the county fair next two years with the JD B guys crying foul with a river of tears. Over the winter a red tractor neighbor removed the sleeves from an H and bored the block to run some other piston with way high compression. It broke the PTO on the dyno and pulled the old step on sled out the end. That was the beginning of the end of farming tractors winning our county fair pulls, LOL

 

[the tractor vet]

Only cast iron pistons i ever found were in Cubs , But this could be to the fact they had been rebuilt and up graded by the time i got to them , i also had never seen a K in the S/N I have run into flat head pistons and power crater / step[ heads and high alt. My one friend had a 46 H that was his main tractior till the 504 came on the seine . When we did the power upgrade on his we found flat heads and this was late 68 and we did a step head with a head shave and bigger intakes some carb tweaking and a lumpty stick regrind with a few tweaks to the dist. , he then could pull 3 x14's in second . But never found any cast iron .

 

[DR. EVIL]

I'm going to agree with Caterpillar Guy, if you want or need more HP an M or Super M makes the most sense. Dad
had a '39 H that he overhauled before I was old enough to run it. I'm assuming Dad put oversize pistons &
sleeves in it. It got traded for a Stock Super H in 1968 and there was no comparison between the two, the SH
would out-work the '39 H without breaking a sweat.
Neighbor had a Farmall 350 gas, had the governor set up to 2000 rpm, maybe a touch more. He farmed 80
acres, the 350 did everything except pick corn with the 2M picker, that went on his Father-in-law's MD. When
he started farming his Father-in-law's 160 he started buying more tractors. Can't remember what came first but
he added a 3020 gas, 4020 diesel with M&W turbo and a Deere 730 diesel. The 730 must have been turned up a
bit, it pulled 4-14's easier than our 4010 and I know it was turned up. generally the guy was terribly hard on
equipment, at his closing out sale the 350 with his loader was the only tractor running.
Anyhow, that 350 would have run pretty close with Dad's '51 M with the 4 M&W Add P'WER pistons in it. The
Super H still has the stock factory sleeves & pistons, YES, 70 years of use on them! The new in box
FIRECRATER'S I bought are still in the box but someday I'll get them in the SH.
I never plowed with the SH, I really don't know for sure how well it would pull 3-14's, but I suspect 2nd
gear is the best it would do, with 2-14's you could run in 3rd. The M's, SMTA & 450 third was always the
plowing gear.