Can It Be Done?

[Bryce Frazier]

Just got an M standard.

Has a JD Loader on it, and a tag on the loader, but it isn't readable. Just the JD part is! This one has AWESOME rear tires, Ford front HUBS and wheels! : and the engine turns over, and well, feels pretty respectable!

Next, I have a buddy that is "giving" me a JD MT, trashed engine, bad tires, etc. It too has a loader, but is very different, 2 way 1 bottom plows, and a M-21 Sickle Mower (which I have parts of one already)

Heres what I am thinking. Another friend has the remnants of a JD 40 engine. Which, IS the same "block" right? His block is trash, but he thinks he has two good pistons..

Question is, can I bore out the block in this M to 40 specs, then drop 40 pistons in there to give it a little more snort? Is it worth the fuss? I LOVE my 40T. Tugs 2x14's around all day, and has never said NO to anything I have asked of it, but I have heard the the M's were a little short on ponies? true?

What do you guys think?

 

[Hay maker2]

(quoted from post at 15:15:07 07/09/15) Just got an M standard.

Has a JD Loader on it, and a tag on the loader, but it isn't readable. Just the JD part is! This one has AWESOME rear tires, Ford front HUBS and wheels! : and the engine turns over, and well, feels pretty respectable!

Next, I have a buddy that is "giving" me a JD MT, trashed engine, bad tires, etc. It too has a loader, but is very different, 2 way 1 bottom plows, and a M-21 Sickle Mower (which I have parts of one already)

Heres what I am thinking. Another friend has the remnants of a JD 40 engine. Which, IS the same "block" right? His block is trash, but he thinks he has two good pistons..

Question is, can I bore out the block in this M to 40 specs, then drop 40 pistons in there to give it a little more snort? Is it worth the fuss? I LOVE my 40T. Tugs 2x14's around all day, and has never said NO to anything I have asked of it, but I have heard the the M's were a little short on ponies? true?

What do you guys think?

I am 99% positive that the M and 40 have the same pistions. The only difference between the two engines is that the 40 has a different governor to allow it more rpm's....
I would go to jdparts.com and review the part manuals for the numbers....

 

[Mike M]

I think you are right. Maybe bigger rod journals on the crank too ? IIRC.
I'm in Ohio and very many of those machines have cracked blocks and cyl. heads. Common spot is behind the carb. and the front of the head. Any uncracked block is worth saving ! I know a fellow bored one out for the 420 pistons. I think that's a 1/4" more ! Don't know how it worked out.

 

[Bryce Frazier]

Wellll, you guys are right!

Just looked on tractor data . com,

Both engines are 100.5 CID

M: 6:1 compression, 1650 rpm
40: 6.5:1 compression, 1850 rpm

Can't believe that little bit would make that much difference? Wonder if I can play with the gov on the m just a little to get a tiny more out of it?

 

[Hay maker2]

I put 0.120" oversized pistons on my MT becuase the block was just plain worn out!

There is alot of material abound the sleeves on the M blocks. I always wondered about going 0.250" over and using the 420 pistions.

 

[Bob Bancroft]

Compression ratio can make a big difference. So if they're the same bore, is it a taller piston, or a different head?

 

[Bryce Frazier]

Good question... Shaving some thousands off of the head couldn't hurt either way though right? I have all the goodies to be able to easily do that!

 

[Mike M]

Just going from an average running worn out one to a REBUILT engine makes a BIG difference too !

 

[M-MAN]

I think you would be wasting your time and money but it isn't my call. Anything you can do with a 40 you can do with an M. Only difference is a 40 will do it a tenth or two of a mile per hour faster. Add another tenth or two for a 420. They all pull the same equipment with the same level of umph.

 

[Bryce Frazier]

Ya, no joke there!

 

[Bryce Frazier]

Well, I REALLY like my 40T, but it is kind of tippy, and I hate that single front wheel (for working with). Plus it is all restored, and I don't like getting it dirty!

The M, being that it is a standard, will pull its 1 bottom plow, and and 8 foot disc, and a little seed drill. Where I am at, LITTLE tractors work better than big ones!

It will be a perfect little tractor for using... I am VERY excited!

 

[RLA]

Bryce,

I own a M I bought for 450.00 with 1 16" plow mounted disc, snow plow, mowing machine & cultivators & 3ph Kit with belt pulley gear box & a JUNK
paper pulley All John Deere equipment. Overhaul Kit's are CHEAP keep it a M or 40. Mine is .45 over sized has plenty of power. Easy to work on &
simple. I overhauled the stuck engine, paid 200.00 for a SP 100 Allis combine for just the tires, junked the rest & made $785.00 in the process
& still have the tires on the M. I love mine & named it the BULL. We use it daily. It could ride better, we have many other larger deere's so I
notice the RIDE.
They are not user friendly to mount & dismount, Brake locks aren't either but the one pictured sports a Frt Mounted E brake. I personally would
not a loader on the row crop model, might consider a loader on a standard or industrial model. Steering box is the weakest link. With Loaded rubber
& wheel weights they pull VERY well. will pull more than they will stop.

2 levers or handles , one is PTO & the other Belt Pulley. Even if you don't need it buy it or pick it up, I did that for the one I have now.

 

[Bryce Frazier]

Oh I brought it home! No worries there! For you guys that haven't seen it yet, check out the post "Forgot Some!" up on Tractor Talk. I posted a bunch of pictures of it. Just came in from messing with it right now.

Took the back hoe down there and got the loader off of it so that I can easily work on it. Looks to be in good shape, but the steering is messed up (imagine that...) Even without the loader on it, it is VERY hard to steer. Maybe because of the bigger tires, but I doubt they would make that much difference?

I am shocked to find remnants of a plastic bag over the distributor. (WOW is all I had to say there) and the fuel had been turned off!! Going to drain the fuel out of it, and get some fresh gas in it, and see if a new battery will make it go boom boom! Maybe, just maybe!

This one also has a paper pulley on the back that is junk. Doesn't make much difference to me, I will just take it off. I have the JD B's, JD GM, and the Ford 2n and Ferguson TO-30 ALL with belt pulleys on them, so, I have options!

I think I will try to get it running and try to use it before I decided to do anything to the engine. IF it is bad, I am going to sup it up a little. More compression, different pistons, etc. BUT, if I can get by with a set of rings, I will just do that...

Glad to hear all the good about yours, I am very excited to try this one out!

 

[David G]

Don't shave heads, change pistons.