JD 2 CYL CUBIC DISPLACEMENT

[GENE DERRINGER]

What is the largest cubic displacement in the JD two cylinder pulling tractors? How often is it required to be rebuilt? Inquiring mind needs to know!

 

[VicS]

What is the largest cubic displacement in the JD two cylinder pulling tractors? How often is it required to be rebuilt? Inquiring mind needs to know!

They are admitting to 1000 cu in. So is probably more. I haven’t pi-r sq. I’m it but 8” bore and 10” in stroke. After market head and block.

 

[VicS]

1005.28 cu for a G JD

 

[gmccool]

Haven't some of the pullers been known to cut out the front of the transmission case so they can get a longer stroke yet?????????????

 

[buickanddeere]

Does not gain anything when the tractor snaps in half due to the block being relieved .

 

[MSD]

What is the largest cubic displacement in the JD two cylinder pulling tractors? How often is it required to be rebuilt? Inquiring mind needs to know!

Right now the limit is 1005 but I know of bigger ones in the works. That's for a model G. There are a few 820 and 830's out there but don't know what they are. Mine is 944 and seems to do well for me. There is always something to fix or redo on anything that is not stock but longevity is pretty good I had in the neighbor hood of 2500 or 3000 hooks on mine before it needed major work. Depends on the components and the assembler how long it will last I guess.

Haven't some of the pullers been known to cut out the front of the transmission case so they can get a longer stroke yet?????????????

Anything over 9 3/8 stroke needs to have the back cut out and some of the top also so the rods clear depending on who made the rods.

Does not gain anything when the tractor snaps in half due to the block being relieved .

They don't break where the back is cut out. Usually under the gov. housing going towards the cam shaft bearing support to on the other side from the gov. housing towards the clutch. Bracing is the key to keeping it together and having it properly tuned so your not pinging it all the way down the track.

 

[EFV]

Does not gain anything when the tractor snaps in half due to the block being relieved .

But it makes a great video for You Tube and when telling pulling stories. " guy just stepped off
tractor like there were stairs" LOL

 

[buickanddeere]

Right now the limit is 1005 but I know of bigger ones in the works. That's for a model G. There are a few 820 and 830's out there but don't know what they are. Mine is 944 and seems to do well for me. There is always something to fix or redo on anything that is not stock but longevity is pretty good I had in the neighbor hood of 2500 or 3000 hooks on mine before it needed major work. Depends on the components and the assembler how long it will last I guess.

Anything over 9 3/8 stroke needs to have the back cut out and some of the top also so the rods clear depending on who made the rods.

They don't break where the back is cut out. Usually under the gov. housing going towards the cam shaft bearing support to on the other side from the gov. housing towards the clutch. Bracing is the key to keeping it together and having it properly tuned so your not pinging it all the way down the track.

How are they clearing the cam with a 9-3/8" stroke ?

 

[used red MN]

Whatever it is the aftermarket supplier supporting this run to the bank smiling!

 

[MSD]

How are they clearing the cam with a 9-3/8" stroke ?

We have 10" cranks that will clear the cam. You need to grind a flat spot on the cam where it meets the rod to get it clear. Been done forever. And working with a good rod maker to design the proper rod gives it clearance also . We also grind part of the oil pump gear on the cam so that a support runs on that spot and will keep the cam from flexing. There is an A out there that has a 10 1/4 crank in it. He moved the cam ahead and has a chain drive on it.

 

[GENE DERRINGER]

What is the largest cubic displacement in the JD two cylinder pulling tractors? How often is it required to be rebuilt? Inquiring mind needs to know!

I want to thank all those who responded to my question. You were very polite. Thanks

 

[560Dennis]

A vendor in Missouri had 11or 12 cubes strokers advertised. Check

 

[MSD]

A vendor in Missouri had 11or 12 cubes strokers advertised. Check

Don't know of any 11 or 12 cubes strokers was you say out there. We do have an 11 inch billet crank on hand and 8 1/4 pistons but waiting on the block and the crank case needs extensive modification to work. We have an A with 10 1/4 inch crank in it doing well.

 

[560Dennis]

Don't know of any 11 or 12 cubes strokers was you say out there. We do have an 11 inch billet crank on hand and 8 1/4 pistons but waiting on the block and the crank case needs extensive modification to work. We have an A with 10 1/4 inch crank in it doing well.

Thank for clarifying This numbers

 

[buickanddeere]

Thank for clarifying This numbers

What is the limit on a 70 or a G . Where a stroker crank and over bore block can be bolted in . With the only structural mods are grinding a flat on the cam shaft ?

 

[560Dennis]

What is the limit on a 70 or a G . Where a stroker crank and over bore block can be bolted in . With the only structural mods are grinding a flat on the cam shaft ?

Best to check with Mel on the limit , I trust what he is proven works. The on line vendors don’t seem to be offer the big cube striker kits now, so that just my observation..