720 diesel

[Deerepower53]

Is it worth the money to get injector work done on my 720 to get more power or should I spend my money in better ways. Thanks
 

[FactoryFarmer]

[buickanddeere]

Easy and cheap to add fuel. Extra fuel is worth zero without extra air.
aircleaner, intake pipe work, port matching, bowl blending, multi angle valve job, over size valves and nail head valves. Cam must be upgraded too.
Still a challenge to flow as much air through those two ports. That other engines use four or six ports to support the same displacement.
 

[gpuller]

Getting it more fuel will make more power., but your going to have to spend money. Larger pumps and injectors cost as much or more than a stroker crank for a gasser.
.22hp/ci is possible with a fresh rebuild and more fuel.
 

[buickanddeere]

Here is a link to some pump data showing body size, element stroke, element dia and delivery volume.
Taking a wild guess the Deeres may have used a C sized body with a 15mm stroke and elements varying from 10mm to 16mm diameter.
The primary reason JD went to 13mm was not to supply enough total volume. 10mm has lots of capacity. The 13mm was used to finish injecting the fuel with the piston is closer to TDC than the 10mm can.
A 16mm element will supply 2.56 times more fuel than a 10mm. Enough to nearly drown a supercharged 830.
Do you understand that after a point ,adding more fuel does not make extra power . It just makes more smoke and washes the lube off the cylinder walls. Causes wet stacking and oil spots, drips and smears all over everything.
Work on the airflow before going past 13mm and 6x12 tips.

http://www.oldengine.org/members/diesel/Injection/CAVpics5.htm
 

[buickanddeere]

This link has some different and conflicting data on the c pump going to 18mm. And includes a Z pump that Deere may have used ?
http://www.oldengine.org/members/diesel/Bryce/Bryce4.htm
 

[Gpower]

10-16mm???? Thats gotta be the dumbest statement on this board. Deere never used 16 mm plungers in any of thier pumps. Deere never made a 6X12 tip either. Obviously you have never rebuilt or made CNC parts for the 2 cylinder pumps, because you would have known that statement is false, and cannot be done. The barrel walls would be paper thin....or not even a wall. Deere used a 10mm and a 13mm barrel and plunger assembly in the 2 cylinder era, nothing else. The reason the 10mm flow the same as a 13mm on the bench is because the helix is ramped down on the 13mm plungers. All Deere wanted to do is increase pressure and injection timing by going to the 13mm plungers.

While there are 15mm barrels and plungers being made, the wall failure rate is inevitable, to thin to keep plungers from seizing over time.

To answer the original posters question correctly, yes spending money on pumps and injectors is one area to improve. Which head do you have? Is it a later black dash tractor?

What are you wanting to accomplish with the tractor?
 

[Deerepower53]

It is the black dash 720 tractor. I want to get some extra Hp out of the tractor for pulling.It will pull stock classes so I don't need to go wild. I would like to know what is the best option head work or fuel work?
 

[Gpower]

For the money youd spend on the head, your not going to gain a lot in return. IE port and polish, get the intake and exhaust manifolds port matched where the openings line up for smooth flowing, no steps or lips. Most of the time they are close, but little things like that dont cost a lot and you can do them.

Gpuller who has posted on here has a 720 diesel, and I built his fuel injection system for his tractor. Maybe he will chime in here and comment on what he thought about it.

I would first check your fuel pressure, see what it running for psi under a load. Lets start there. 30-50 psi under a hard load is good, I have run electric pumps to keep it around 100psi before, but did not see any real gains in that, but it did not stumble either.

Convert your air cleaner to a dry air type. Good clean air with minimal restrictions goes a long way. You should have 13mm pumps in your tractor with 6 hole .010 dia injector tips...that was factory for them. If the pumps are Bosch pumps I can get you bigger barrels and plungers, as well as injectors to help.
 

[Gpower]

That link has absolutly nothing to do with 2 cylinder John Deere fuel systems. There is not one part on that link associated with a 2 cylinder fuel system. Not sure why that was posted..has no relevence to the question
 

[gpuller]

[buickanddeere]

Are you saying that neither the Bryce or CAV elements can not be made to work in the JD pumps. Instead of machining custom plungers and sleeves?
 

[buickanddeere]

Only if there is avaliable oxygen to combine with
the fuel.
 

[buickanddeere]

That is what I said. The 13mm pumps have the fuel delievered while the piston is closer to TDC than a 10mm pump can.
 

[gpuller]