Farmall m piston question

[farmalldave]

I have a 1944 farmall m with flat top pistons original .The engine is tired and started having oil foul out my spark plugs. My question is does it matter if I buy a stepped head piston and sleeve kit or do I have to put a flat head piston kit back in. I'm not doing a full restoration on the m yet just using it around farm to pull wagons etc .

 

[used red MN]

I have a 1944 farmall m with flat top pistons original .The engine is tired and started having oil foul out my spark plugs. My question is does it matter if I buy a stepped head piston and sleeve kit or do I have to put a flat head piston kit back in. I'm not doing a full restoration on the m yet just using it around farm to pull wagons etc .

Put in the stepped head pistons. What do you know about the tractors history? It is possible it is a distillate tractor in which case the head has larger/deeper combustion chambers that lower the compression more.

 

[farmalldave]

Put in the stepped head pistons. What do you know about the tractors history? It is possible it is a distillate tractor in which case the head has larger/deeper combustion chambers that lower the compression more.

I have never identified a distillate head before but this one is pretty deep. Is this a distillate head. So the stepped head piston will work no problem with this head right?. Of course I'm planning on working on the head.

 

[RedMVa]

I have never identified a distillate head before but this one is pretty deep. Is this a distillate head. So the stepped head piston will work no problem with this head right?. Of course I'm planning on working on the head.

Yeah that looks like a distillate head , the head numbers are on top in the middle. I’d try to find a good gas head but that’s your choice. No problem with putting step head pistons in, especially with that head.

 

[farmalldave]

Yeah that looks like a distillate head , the head numbers are on top in the middle. I’d try to find a good gas head but that’s your choice. No problem with putting step head pistons in, especially with that head.

I just installed new sleeves and pistons in my bn wasn't bad at all. Thanks for the reply

 

[BarnyardEngineering]

Can you even get flat head pistons anymore? You may not have a choice in the matter.

As I recall the last time I heard about someone looking for flat head pistons for "originality" had a hard time finding them. Most only stock/sell stepped head pistions, as they have been the overwhelmingly popular choice for 50+ years.

Stepped head will work fine. There's actually more room in a distillate head for the steps than a gas head.

 

[used red MN]

Can you even get flat head pistons anymore? You may not have a choice in the matter.

????!! YT flat head OVHL set
Getting NOS cast steel pistons might be another story. On another note find me someone that is going to pay more for an “original” Farmall M tractor because the engine has stock cast flat head pistons. To each their own.

 

[RedMVa]

????!! YT flat head OVHL set
Getting NOS cast steel pistons might be another story. On another note find me someone that is going to pay more for an “original” Farmall M tractor because the engine has stock cast flat head pistons. To each their own.

I bought one of the last oem step head sets from IH a couple years ago. Son of the IH dealership tried to get some after I ordered them and they were NLA. Flat heads are few and far between and valves for a distillate head have been hard to come by for several years unless that’s changed, very few people want either of those

 

[farmalldave]

Alright I removed a bearing to measure the size. After removing the bearing I noticed it had a bad spot. Also the journal has a crease down the middle. The crease is not sharp like a burr. Will this be alright to throw new bearings on. I don't plan on using this tractor heavy just pulling wagons around the farm.

 

[Mrfred54]

What size are the bearings? STD. Or has the crank been turned already. Get some plastigauge from auto parts store and check running clearance. If the bearings are STD. and check with plastigauge and you have more than .003 running clearance you can get .002 over size bearings.

 

[farmalldave]

What size are the bearings? STD. Or has the crank been turned already. Get some plastigauge from auto parts store and check running clearance. If the bearings are STD. and check with plastigauge and you have more than .003 running clearance you can get .002 over size bearings.

Std

 

[D Slater]

I have never identified a distillate head before but this one is pretty deep. Is this a distillate head. So the stepped head piston will work no problem with this head right?. Of course I'm planning on working on the head.

Hard to tell from picture what head is. M gasoline head looks somewhat deep compared to some. Look on head where number is in picture. Later head in picture, 44 should have 4 numbers followed by two letters.

 

[used red MN]

Alright I removed a bearing to measure the size. After removing the bearing I noticed it had a bad spot. Also the journal has a crease down the middle. The crease is not sharp like a burr. Will this be alright to throw new bearings on. I don't plan on using this tractor heavy just pulling wagons around the farm.

Always hard to asses something like this by a picture. To me that crank is borderline, to the point that if it was to be a “working” tractor I would say it need’s reground or replaced to make it a solid reliable overhaul. But it is a slow turning engine with a fairly good sized rod bearing for a less than 4” piston. Give it a good shining with some 320 tape and a quick finish with 400. Without putting a mic on it or at least feeling the step to to unworn edges of the journal I am not sure how successful you will be at fitting an .001” or .002 undersized bearings in there as Fred mentioned. How was the oil pressure on the tractor before?

 

[Janicholson]

Std

The missing chunk is called spalling. It is an indication that more will happen in that area. It is toast. I don't mind the journal, I think it will work if the clearance is in the .002 to .003 range. Jim

 

[caterpillar guy]

Polishing with just some emery cloth will leave the mark as a hump or groove depending on which it is. IF a hump use the emery cloth on a file to make the hump disappear on the journal. You will have to go all the way around it though to do that. the file is only to make the emery cloth touch on the hump and not on everything else as you work it. Reason for the file is is does not give much like a piece of sheet steel, or wood can crush slightly. The file will stay flat and straight.