Farmall H-gas and distillate

What was the purpose for distillate? Did it give you more power? Better mileage? Longer life? I have one and I need a new manifold. Should I look for the same manifold or just gas? I got the old girl running and took it for a ride today, she has an odd miss. My new muffler hasn't got here yet so I noticed flame in the stack each time it missed. Doesn't miss like a plug or wire. I wonder if it could be a stuck valve. It isn't constant so I would like to believe it's not a burnt valve. As always I would like to thank everyone in advance I look forward to all your help. Thanks, Dave

yup, sticky valve would be my first thought. Distillate was a much cheaper fuel in the day. it did not produce the same HP as gasoline, it produced less.

Thanks Tom, I guess there is no need to buy a distillate manifold.

distillate was basically the waste product from the inefficient refining process used at the time. WWII created a huge increase in the need for gasoline and with it improvements in the process that increased the amount of gasoline refined out of each barrel of crude. The distillate was much cheaper than the gas, and we all know farmers like cheap. It has very poor anti knock qualities requiring very low compression ratios, about 4.6:1 max meaning it makes less HP than an engine designed to run on gas. After WWII distillate use tapered off and by the 50s was eventually gone for the most part.Higher performance gasoline, LP and diesel took over.

The only reason to buy a distillate manifold would be to do a "correct" restoration. They are hard to come by in decent shape with the heat butterfly intact and working. So, if you are just interested in making her run right, buy a good used gasoline one, or a new one if your pocketbook allows.

On the valve front, I would take the valve cover off, and give all the valves a good coating of clean oil. Sea Foam. Blaster. marvel mystery oil. Really whatever your favorite oil is. I am not trying to stir up the penetrating oil (snake oil) debate, just giving you options. Personally, for something like sticky valves, I like MMO, but each has their own opinion. The important thing is to get the valve stems and guides thoroughly lubed. If the old girl has been sitting for awhile, a sticky valve is NOT unusual. Kerosene or diesel would work as well. Important thing is that the oil used is low viscosity.

I like to take the valve cover off. Give each valve a good soaking in MMO, while occasionally turning the engine over by hand. Making sure each valve is moving, and coated. Best way is coat, turn 1/4 rev, coat again, another 1/4 rev, and continue until you have turned her over through the whole intake/exhaust cycle for all 4 cylinders. you can even do it with the engine running and the valve cover off. either way, get those valve stems and guides lubed.

If that doesn't solve things, let us know and we can go from there.

Little intro: I appreciate all I read here. I have been a long time lurker. There are some very knowledgable folks (rusty farmall is tops on my list--no insults to others) here abouts, and I appreciate all I read and learn.

Bought my little house in east Georgia in 1999 and a Farmall H came with it. Got her started and have rehabbed her as needed. She runs fine but smokes a bit. Guess you know the old girl. I just use her to mow a bit and to tinker. I have a little Kubota estate tractor to do my big chores.

re: the manifold

My "49 H was also a distallate tractor; no suffix on the ID plate, and you can see where the gasoline tank had been removed along with the shutters. She is now all gas. I was bush-hogging the edge of a field, using the muffler to push branches out of the way (we"ve all done it) and the top piece of the manifold broke. No J-B weld repair here, so i ordered up a new gas manifold from Steiner. It was not too difficult to install. The old manifold looked a little different and was crapped out.

Little Red now runs better, sounds better, and doesn't backfire when I shut her off if i don"t cut off the gas. It is amazing that a 64 year old tractor will still run and perform like it should.

New gas manifold? Yep, it"s the way to go.

Your right Tom, she was setting for a long time before I got her. I also like MMO. I'm going to run it a while and see if it gets better but I probably will follow your advice. If the distillate model had low compression pistons, I guess it would have more power if I changed them. I have heard the term Firecrater pistons. Is that the way to go?

Dave, to be honest, I am not that familiar with the H and M distillate models. I know for sure that there is a distillate head and a gasoline head. Not sure if they had different pistons or not.

Now, on the C-113 engine which was the A, B, BN, and C, there absolutely was a piston swap out for the distillate conversion. concave piston tops, lowered compression using the same head for gas or distillate.

so, someone who knows for sure will post and set thing straight. My belief is that the C-113 engine kept the same head but changed the pistons. The H and M I believe kept the pistons, but changed the head.

Those who truly know will correct me or support what I have said.

PS Firecrater pistons will certainly raise the compression, but to do it right, make sure you have the gasoline head as well. I can look up the part numbers for each head, or someone may post it.

Thanks Tom, what part of Pa. are you in? I'm in Columbia county. Got any good tractor junk-yards in your area?

Dave, I have an M that had distillate pistons, head, and manifold. I kept the head and rebuilt the engine with gas step head pistons to make up for the loss of hp with the distillate head and I replaced the manifold with a new gas manifold and it runs great. Go with the gasser unless your looking to restore the tractor to original...

Distillate was a cheaper less HP option around WWII and they made them through the Super MTA I believe. The tractor started on gas (You should have a small tank in front of the larger tank or at least a hole in the hood for the fill hole) and then was switched to distillate once the engine was hot. Distillate and Kero tractors usually had radiator shutters as well to help with the heat build up. hope this helps a little...~Anthony

The last Distillate option was with the 450 series. Very few of those were produced. Jim

Where did you buy a new manifold? Was it made it in China? Did it fit right?

Anthony, It have the tank and manifold. I didn't find a line to the carb, just the gas line. I don't see any shutters. Thanks, Dave

Thanks Jim, I think I'll look for a head and manifold when I'm ready to rebuild the motor. I wonder what the difference is between the two heads? Thanks Dave

Thanks for the information. Dave

Dave, I am about 25 miles North East of Pittsburgh, Natrona Heights / Freeport area.

Once the tractor was used primarily with gas the shutters were probably removed since they were no longer needed to help quickly raise temp. All that was left on my tractor was the rod that opened and closed the shutters, they were removed long before. Keep that small tank, it's a great conversation starter when talking with other tractor guys! ~Anthony

The gasoline head for many Farmalls has a smaller combustion chamber than the distillate head. (some small A and B farmalls had cup shaped piston tops to lower compression, some had different head design as did the C)
The difference in compression is often from near 5 to one to near 7 to one on various models. (I am not being specific as the issue is only that a working tractor will be HP ahead with a gasoline head. Jim

distillate... you could mix a 50/50 ratio of gas and diesel in your tractor and then this would give you an idea of the disadvantages of using it. hard to burn and what does not burn goes into the oil pan and dilutes the oil. oil level has to be drained daily. engine wears out faster... its garbage. engine has to be hot when switched over.
reminds me of my 1974 ford 1/2 ton 390 cid I had years ago. put some diesel in one tank for the heck of it, then get going down the hyway and pass people then flip the switch to the diesel and give a smoke show.lol.

Thanks Jim, sounds like I won't know for sure what I have till I take it apart. It may have been apart a few times already. I wonder if there is a way to identify one head from the other. I guess it could have been changed before.

Thanks Red, good information.