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Discussion Starter · #1 ·
When I was at my Deere dealer today, they had a free hand out titled "Off-Highway Diesel Engine Ratings" that gave information on their PowerTech engines. My 4520 has the PowerTech E 2.4L engine in it (I think...), and that was covered. I've got a scan of that page. When you're at your Deere dealer, check it out or stop by and get it (hope that makes it OK to post a page from the handout here... I'm telling people to stop by their dealers!)

For the bigger engines, they had HP and torque curves. Unfortunately, no curves for this engine. But if I look at the 60HP one, it's interesting to see that the peak HP is at 2400 RPM but the peak torque is at 1800 RPM (if I'm reading this right). Many of the bigger engines had this same torque curve peak. I've heard people saw that when the diesels lug down they have more torque and that's how they power through it. I know the math, but I'm always wrestling with HP vs. Torque. Anyway, these numbers support that situation. The book defines "Torque Rise" as:

% torque rise = max torque/torque at rated speed

and for this engine that's 37%. I don't feel so bad about doing light cutting of the fields at 1800 to 2000 RPM instead of full speed now.

The brochure also shows the various things done to engines of all sizes to meet the emissions requirements, and shows when and when those requirements are going.

Anyway, it's an interesting brochure and it's nice to see some torque/hp curves for some engines. If I'm not reading this write or have totally blown identifying the engine in my 4520, educate me!

Pete
 

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I am sure you have the same engine. Here are the specs from Deere's site:

Manufacturer John Deere 4024T
Engine HP (kW) - gross 60.0 (44.1)
per ISO 97/68/EC PTO HP (kW) -
Gear transmission 52.0 (38.8) per SAE PTO HP (kW) -
Hydrostatic transmission 50.0 (37.3) per SAE
Rated engine speed, rpm 2400
TypeDiesel Operating range 950-2600
Aspiration Turbo
Cylinders/Displacement, cu. in. (liters)4 / 148.9 (2.44)
Cylinder LinersCast-in-block
Bore and Stroke, mm (in.)86x105 (3.39x4.13)
Compression Ratio20:1
LubricationPressurized
Cooling SystemWater pump
Air CleanerDry type w/ safety element and air restriction indicator
Engine ShutoffKey switch
Engine Torque @ rated speed, ft./lb. (N/m)112.92

I would not feel bad aboput cutting at 1800 ro 2000 rpm's ever. With the E pto available on these machines, the engines have been designed to run under stress at 1750 up. Anytime you can run less than full throttle and not over stress the machine is great. Less wear and tear on everything!

I wish I had more time in the seat on the new tractor, but this engine was one fo the things I was really looking forward to. The torque compared to the 3720 is unbelievable.
 

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Pete,
I would think you can do light cutting with the economy pto setting at 1740 rpm. This would allow your cutter to turn at max speed in most conditions while providing plenty of inertia to power through the occasional thick clumps of grass and weeds. Whether to use the epto or standard pto is a trial and error basis, somethimes it may take all the power you have but not often. A 4520 has more than enough power to operate the MX6 in very tough conditions, as you have found out already the physical size and weight of the mower is more of an issue than the power to turn the blades. With all the front weight you have your tractor and hog should be able to kick butt.
 

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I have not been able to try my MX6 behind my 4520, but i have read that it will almost stall the tractor when turning it on in epto. Either of you had that experience?
 

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Brian,
It is a good size load to start up and will drop the rpm's substancially for a second or two but it does work. I start mine at about 1500 rpm in both the 4520 and the 110 regardless of the epto or standard setting.
 

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Discussion Starter · #6 ·
I start my MX6 at 1500 in normal PTO, and at the full 1750 in ePTO, but have only done that a few times. It really bogs it down and rattles it for a bit. If it's just cutting the grass again (not the 1st cut of the season or an area that gets cut a few times a year) the MX6 cuts good at 1800 rpm. I suspect as I get more confidence and since I'm past the break in point (does that even make a difference?) that next year I'll be in ePTO more for "mowing the field" cutting. Like Steve said, trial and error, experience.

I did get to cut a field that's a "mow once a year". The 4520/MX6 handled it just great at a 5 MPH speed. I've tried to cut a section of it with the 318 once, it took 4-5 passes at about 1.5 MPH. It was a "yep, this was the right tractor to get" moment.

The MX6 has a very high blade speed (I think it's 198 MPH) compared to other cutters, that might be why I'm getting by at 1800 RPM. All part of the learning curve.
 
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