Well, I tore into our 1940 Farmall M today. It had 60 psi on cylinder 3 and 80 on the remaining cylinders. The head gasket was blown out between 3 and 4. The problem is that cylinder 3 also has at least 3 or 4 sets of corrosion grooves where the piston had been sitting in one spot for a long time with the valves open. It also appears to show evidence of discoloration of the metal, but it could also be rust damage. 2 and 4 have less pronounced grooves as well. Three of 4 pistons are covered with a blanket of prickly black carbon (burning oil?). The grooves on cylinder 3 are deep and easily catch your fingernail. All 4 bores have no remnants of the crosshatching on the cylinder sleeves. Additionally, I can wiggle the pistons in the bore at least 1/16 inch if not more. I was wondering about the following:
1) Does the above sound like grounds for a rebuild? (just want to make sure I am not being overly fussy; I don't want to part with more money than I need to) It is a work tractor, so it needs to be dependable.

2)It has 4 inch thin wall sleeves with what appear to be original aluminum IH firecraters installed under a 6336-DD Kerosene head. Can I still get a set like this (along with all of the gaskets, pre-overbored 4" I.D. sleeves, mains etc. for an inframe, where is the best place to get them, and what will the damage (to my wallet) be?
3)Is there anything I should know or check to make sure I don't rebuild it and wreck new parts?
4)It overheated idling for 15 minutes on a 70 deg day in neutral last year, which triggered the head gasket failure. I since found out that there was not thermostat installed, so it definitely wasn't the problem. The radiator and hoses are all new and the water pump belt was new and properly tensioned. It has no coolant ending up in where it doesn't belong, so I am wondering if anyone has an idea what would have caused such a severe overheat. Only thing that springs to mind is water pump. I just don't want to repeat this incident again in a year.

Thanks.

I'd go over that radiator inside and out with an air gun and 125 psi. You won't believe how long the dirt will fly out of there.
At a mninimum you need rings and sleeves. What did the valves look like?
The quwation is, How many times do you want to open this thing up an tear it apart? DO it all at once or one at a time?

Gordo

I would say that if you're going to work the tractor you need a rebuild. You can get the parts from a bunch of different places, this site and CASE IH included. Sam

Your best best is to just go ahead and buy an In-Frame Overhaul kit. I sell a lot of them and it is more expensive to just get a few pieces of a kit than it is to buy the entire kit. The manufacturers of the kits typically give large discount for buying the complete kit rather than individual parts. Another thing is that if your sleeves have grooves as bad as they sound then they are not any good anymore, if you hone them enough to get rid of the grooves then the bore is going to be too big for a set of rings to seal good, the bigger the bore gets the more end gap the rings will have, allowing more compression past. By the time you buy rings, sleeves and gaskets, you could buy an inframe overhaul kit and get the pistons as well as rod bearings. As far as the 4" overbore kit, that is now standard practice when overhauling an M and it has been that way for some time, it is actually more expensive to buy a rebuild kit to put it back to 3 7/8", than it is to buy a 4" overbore kit.

If you have any more questions or want to check on a price for a kit call me. (859) 433-5798

If you're going to invest all that money in your engine you should pull the engine and do a complete rebuild. Your block probably needs to be dipped, new cam bearings should be installed for good oil pressure. The crankshaft needs to be measured for wear and let your local auto machine shop decide if it needs to be ground undersize or just polished. Let them furnish the correct bearings. Have them redo the head too.
Its a good time to look at your clutch while you have the engine off. Hal

I guess I wasn"t quite clear, which is my fault. I have no intention of re-using the sleeves. They are thin wall sleeves to begin with and they have grooves in them that are at least 15 thou deep. It would probably need to be bored 20 or 30 thou over just to clean them up, and there are no pistons for such an odd bore, as the next size is 4.250". I am wondering if I can still get firecrater piston kits that are the same as what was in it in an in-frame kit. All the kits I"ve found have been flat tops, which I don"t want with the low compression kerosene head.

Chadd,it heated up cause it DIDNT have a thermostat.Without one the water circulates too fast and doesnt get a chance to ool off.Thermostat is there for a reason. Hoss

yes there is a reason for a t-stat, but too fast a flow to cool the water ain't it. just another of those myths that just will not die & 'people' just keep them going like this

On some vehicles a removed thermostat will cause over heating,I had a 69 Grand Torino with a 390 motor,As a young teenager I thought the answer was to remove every thing I could to make more HP,including the air condition{dummy},The car started to over heat immediately,I stopped at a garage and the old man their told me to put the thermostat back in.I did and never had any more problems

Well, it is hard to argue with someone's PERSONAL experience, but from a purely technical (thermodynamics, heat transfer, academic) standpoint, it does not compute. AND, from my own personal experience for 50 years/many engines, they all have ran cooler without a thermostat. AND, it should be noted that the small block Chevy was introduced at 265 cubic inch with a 48 GPM water pump, increasing to 85 GPM by the time it reached 350 cubic inch Corvette HP trim. GMC had a 305 V6 that pumped 135GPM in 1960 and the little N Fords pump 16GPM. So you have a hard row to hoe to convince me that greater flow can make an engine run hotter.

I believe the higher cooling system pressure maintained by a thermostat can keep the water from evaporating (boiling). Heat transfer to vapor is lousy compared to liquid (much higher cp for liquid).

I'll agree with others you need to consider an overhaul with dome pistons, they are available.
What do you have for a sleeve puller? If you need to purchase one E-mail me. I have a very nice unit that will do the job. Good luck