F-12/F-14 conversion

I have a '37 F-12 that was converted to an F-14 at some time in its life. It has been in the family for a long time. My grandfather is the second owner.
In the limited research that I've done I know that some of the F-12s were held back at the factory to be converted in late 1937, some were converted at the dealerships and kits were available for the everyday farmer to buy. I'm familiar with the differences between the F-12 and 14. The serial # on my tractor is 109588 which I believe puts it close to the tractors that may have been held back at the factory and converted. To the untrained eye it looks like an F-14. Elevated steering, higher seat, longer brake levers, crankcase breather.
Do any of you guys have any experiance with any of these tractors that have been converted? I'm wondering if they put a F-14 head on them?
I'm buying a complete '38 F-14 and plan to combine the two and end up with a nice complete F-14. I also just baught a Heisler overdrive for a F-14. It is in amazing good condition. All the bearings are in perfect condition and the gears have nearly no wear.

The F-12 to F-14 conversion kits did include an F-14 head. It also included an F-14 serial number plate. I suppose field or farmer conversions may not have gotten the new serial number plate. But it is near certainty that any still belonging to IH got a new plate, and likely that any new stock at dealers got the new plate as well.

I feel pertty confident your tractor didn't get converted when new. It may have been converted (possibly partial) just before your grandfather bought it. Production of the conversion packages wasn't authorized until 6/38. The conversion serial numbers were all in the 1939 range.

I have always wondered if the tractors held back at the factory received a new serial number tag.

What is the part number for a F-14 head and where exactly would it be located?

I know you see a lot of F-12s that seem to have more of a poor man's conversion. Steering is raised and maybe the seat post has a pipe welded to it to make it higher. Same goes for the brake levers and that seems to be all that has changed.

On my tractor all those things seem to be factory parts. Nothing seems to be welded or put together with everyday scrap pieces. Plus it has the breather on the valve cover.

Did the F-14 receive a different governor or was it just adjusted to run at higher RPMs?

Did they use the same engine block? I'm curious about this because the block on the F-12 that I already appears to not be cracked externally. It at least has no welds. The block on the F-14 I'm buying has been cracked and welded in a couple spots. I hope I do have a F-14 block on my F-12 then I at least have two to choose from when I get this project started.

My F-12 was a kerosene tractor with the dual tank. The F-14 was a straight gasoline tractor. Both tractors fuel tanks are in good shape. As far as having something that's more rare would I be better off using the duel tank with the extra fuel lines and valve or go with the straight gasoline tank and build the tractor using it. Neither manifold is usable so I'll be searching for a new or good used manifold.

I agree the f-12 converison kit contained an f-14 head. Some that were converted did not get the new serial # plate changed.Think my book gives what # they started at.Will see if I can find it.

Does the serial number on the tag match the number on the engine? I would use the gas tank and maifold set up, I think there were less of them than distilate and it will be easier to deal with. I have a 37 F12 with the wide front and heisler overdrive, remember the pto and belt pulley speed up too so you may want to remove the pulley. Whats the deal on the front axel? It looks like a model A ford wheel on it.

I'm reasonably sure the block was the same. At least the changeover package didn't include one. I don't know about the governor. Maybe they changed the governor spring?

I forgot to mention that.

The guy who owned the tractor before my grandfather put that wide front on the tractor. For a "custom" job he did a very clean retro-fit. The set up is completely bolted to the tractor. Nothing was welded to any part of the structure of the tractor. I always wondered what it was off of. I figured it was just a solid axle off a car. I have the original narrow front for the tractor. I most likely won't leave it on but it is a neat custom wide front.

I have in front of me two IHC brochures from the 30s.
For the F-14, ground speeds are listed as 2-1/4, 3 and 3-3/4 mph.
PTO speed is 550 rpm.
Belt speed is 2580 feet per minute.

F-12 ground speeds are the same.
PTO rpm is 538.
Belt speed is 2591 feet per minute.

These are all very close. I don't think there was a standard PTO speed back then, but most manufacturers seemed to make their PTO speeds around the 540 mark. As to belt pulley speed, there must have been some sort of bench mark there, too, because all the tractors listed in one of my IHC brochures have pulley speeds
just under or just over 2600 feet per minute. I expect that most driven machines (threshers, for example) were designed to be driven by tractors with those belt speeds.

I THINK that the way that engine speed was increased while ground speeds and the pulley and PTO speeds were kept about the same was via a change in the ratios at the input to the transmission. It is not clear how the ground speeds would remain the same while the PTO and pulley were slightly different. I wouldn't be surprised if the published speeds don't match up exactly with the real speeds, which would be just very slightly different (there is about a 1 to 1.5% difference in the PTO and pulley speeds). I would be glad if someone who knows these things better than I do would say whether or not this is true.

The governed engine speed on the F-14 was raised from 1400 to 1650. This could have been done with
some adjustments to the various levers involved, but possibly also with different springs. Again, I hope people who have first-hand experience with these things will reply.

The external changes--higher seat, raised steering wheel, longer brake levers, longer clutch pedal, higher throttle bracket, valve-cover breather--were basically bolt-ons (except for the u-joint in the steering--unless the changeover kit contained a complete steering shaft with u-joint and worm--this I don't know). When I was a young whippersnapper, I made a DIY conversion to a higher steering wheel and raised seat (raised the seat with a block of wood; for the steering, got a B u-joint and put it on the shaft after I cut it in two; I don't remember how the joint was fastened to the shaft; this was about 65 years ago--just long enough so that the details are now just a LITTLE bit fuzzy).
By the way, users were advised back then to take the pulley off when it wasn't being used. Since it was heavy and ran all the time, it was probably somewhat hard on the pulley shaft bearing. We didn't use ours that much, so the little cover was always kept on the shaft, to keep dirt out of the bearing.

I have been told that the in put bevel gear is diffrent on the F14 over the f12. The F12 is a straight cut bevel gear and the F14 is a heilical cut bevel gear. So the input ratio is most likly a little diffrent.

I bought an f12 in 1993 that was advertised as an f14. The serial number on the tag and the block serial number indicated it was a 1937 f12 but it had all the attributes of an f14: steering post, oil breather, head and transmission changes. I bought an overdrive for an f12 and it would not fit. The bevel transfer gear for the true f12 had a larger OD than the f14 with a different pitch diameter and a different number of teeth.
The fewer teeth on the smaller f14 transfer gear mated with the larger gear it matched up with would give the tractor a slower speed. The r.p.m. of the motor was speeded up to give more horse power at the same speed.
Good luck on finding the proper overdrive. I saw one at Kings tractor auction that went really high. Dal Wolf