B3300SU tractor-loader with Kubota's four (4) cylinder,
91.4 cubic inch diesel engine with 25 gross horsepower.
L3560 tractor-loader with Kubota's three (3) cylinder, 1
11.4 cubic inch diesel engine with 37 gross horsepower.
The
L3560's three cylinder engine has more torque and is considerably quieter, though powering a much heavier tractor, than the four cylinder engine in the B3300SU.
An excellent topic to discus. The old saying there's no replacement for displacement really comes into it's own in your example here.
B3300SU
4cyl. (91.4ci/1.5L)
Bore/Stroke: 3.1x3.1in [79 x 79 mm]
Power (gross):33 hp [24.6 kW] @2700RPM
L3560
3cyl. (111.4 ci/[1.8 L)
Bore/Stroke: 3.4x4.0in [86 x 102 mm]
Power (gross):37 hp [27.6 kW] @2700RPM
This isn't exactly an apples to apples comparison, but it works all the same. The B may have a 4cyl but its displacement is considerably less than the L's 3cyl engine. So are the bore and stroke, the stroke on the L's engine is quite a bit longer actually. While 4 HP may not sound like a lot it certainly makes a big difference. And the much longer stroke is really what gives a engine with 1 less cylinder the ability to out pull, push, tow, and maintain more consistent speeds going up grades with heavy loads, especially in higher gears or at lower RPMs.
What I think would be a more apples to apples comparison would be with the
L4060. They are the same class/size tractor and much more comparable.
L4060
4cyl. (148.5ci/2.4 L)
Bore/Stroke: 3.4x4.0in [86 x 102 mm]
Power (gross):42 hp [31.3 kW] @2700RPM
While the 4060 has grater displacement it has the same bore/stroke as 3560. So in this case "all things being equal" because the tractor itself is the same its the 4th cyl that makes the difference. The 4060 is going to out do the 3560 in situations were torque is what gets the job done.
The reason I bring this up is when I was tractor shopping I talked to a guy that ran a small business fixing and building driveways and private roads that were often gravel and usually long (several hundred yard hilly driveways and mile long private roads are common here), he had a 3560 when he started and it didn't take him long to start running out of grunt. He promptly stepped up to the 4060 and was good to go from there on out. His advice to me was this, if you are pulling, pushing, moving heavy things up hills, slopes, or long grades you'll need lots of torque. And the extra cylinder will allow you to do the same job with less rpms, less fuel, and in less time. I headed his advise and haven't regretted it. Nalle may have no need for that much power or torque, just thought it was worth mentioning.