Importance of Engine Displacement when Comparing SCUT/CUTS?

[Otto33]

Is there any practical benefit in choosing a tractor with a larger/smaller engine when the HP is maxed at 24.5?

I'm looking specifically at the Kioti CK2510 with a 100CI/1637CC engine vs a Kubota B2601 with a 68.5CI/1123CC engine. So, a roughly 30% smaller engine for the Kubota. Even the B3350 has a smaller engine than the Kioti despite the relatively large difference in HP.

I know that, all other things being equal, a larger engine should have more available torque at lower revs, but is that advantage completely lost when discussing PTO driven implements?

Or, with machines this small, is the extra displacement just a waste of fuel?

 

[nards444]

Is there any practical benefit in choosing a tractor with a larger/smaller engine when the HP is maxed at 24.5?

I'm looking specifically at the Kioti CK2510 with a 100CI/1637CC engine vs a Kubota B2601 with a 68.5CI/1123CC engine. So, a roughly 30% smaller engine for the Kubota. Even the B3350 has a smaller engine than the Kioti despite the relatively large difference in HP.

I know that, all other things being equal, a larger engine should have more available torque at lower revs, but is that advantage completely lost when discussing PTO driven implements?

Or, with machines this small, is the extra displacement just a waste of fuel?

im not a huge tech guy when it comes to things. But you got cams, injection, breathing, exhaust, material of the block, heads, all this stuff makes a difference. The days of bigger engine means its better are long gone. my 98 chevy was a 5.7 and produced 250hp give or take, my 19 ford is a 5.0 and produced almost 400 hp.

 

[jeff9366]

Kubota equivalent to Kioti CK2510 is the Kubota L2501, which is a little heavier and has a three (3) range HST transmission.

Kubota B2601 is 1,632 pounds bare tractor with a three (3) range HST transmission.

Kubota L2501 is 2,623 pounds bare tractor with a three (3) range HST transmission.

Kioti CK2510 is 2,260 pounds, bare tractor with a two (2) range HST transmission.
The Kioti CK2510 needs the 100 cubic inch engine to move its additional 600+ pounds.

On sloping land, with a flail mower and an FEL you may want the lower/LOW of a three (3) range HST regularly.

All three tractors above are considered compact tractors based on 12" ground clearance.
(Subcompact tractors have 7" to 9" ground clearance.)

Compact tractors with relatively large diameter wheels/tires have more tractive power pulling ground contact implements, pushing a loader buckets into dirt and pushing snow. Larger wheels and tires permit bridging holes, ruts and tree debris with less operator perturbation.

The fundamental importance of TRACTOR WEIGHT eludes many tractor shoppers. Heavier tractor weight is more important for most tractor applications than increased tractor horsepower. Bare tractor weight is a tractor specification easily found in sales brochures and web sites, readily comparable across tractor brands and tractor models, new and used.

Shop your weight range within tractor brands. Budget will eliminate some choices. Collect a dealer brochure for each tractor model in your weight range. Spreadsheet tractor and implement specs, often a revealing exercise.

When considering a tractor purchase, bare tractor weight first, tractor horsepower second and (narrowly) rear wheel ballast third.

 

[Otto33]

I appreciate the replies. My comparisons definitely muddied the waters more than I intended.

The question I should have posed was, at the same HP rating, will tractors of comparable size/weight have comparable abilities, regardless of engine displacement?

 

[4570Man]

I don’t think it makes any difference. A turbo vs no turbo at equivalent hp might be a difference.

 

[finn1]

If you’re going to play that game, be sure to include the Kioti CK 2610 in the comparison: it outweighs both the Kubotas at 2701 lb, has a 3 range hst, and the larger displacement100 cu in engine.

The fundamental importance... bla, bla, bla.

 

[Croomrider]

I don't think it makes any difference either. Horsepower is a function of torque times RPM's. You will generally find that a smaller displacement engine will make it's rated horsepower at a higher RPM than the larger engine, unless it's turbocharged. There are different ways of designing engines and both of these approaches should be fine for our uses.

 

[LS Tractor Owner]

The difference in displacements determine at what rpm the hp is developed. I had a 25 (24.7) HP SCUT with a 77.3cc displacement. It's HP was made at 3100. My new LS compact 25 (24.6) HP has 80.4cc displacement, but makes its HP at 2500 rpm. Even for the basically the same HP, the compact makes more PTO HP (just a little) but definitely feels like it has more torque. I'm not sure of the actual torque numbers.

You mentioned fuel usage... My slightly larger displacement tractor (much bigger tractor overall too) uses less fuel than the SCUT did.

 

[sd455dan]

If youæ±*e going to play that game, be sure to include the Kioti CK 2610 in the comparison: it outweighs both the Kubotas at 2701 lb, has a 3 range hst, and the larger displacement100 cu in engine.

The fundamental importance... bla, bla, bla.

Yeah or the new Branson 2515H if it ever gets to the dealers.

outweighs the Kubota and the kioti
has a 3 range hydo with throttle link
1.7 litre engine

2400lb 3 point lift @ 24 inch behind the ball ends

2200lb at the pin to 104 inch BL 150 FEL lift

https://www.tractorbynet.com/forums...240_680335079049497_6629914584159354880_n-jpg

If /when Branson actually delivers

Rated RPMs can make a big difference

as an example my old chinese tractors engine was also available in boats and they cranked the tractor which was rated @2000 to 2800 rpms for boat use
800 RPM added over 20 HP to the data plate

 

[dodge man]

I just bought a JD 2025R which has a 1.3 liter 25hp and traded in a Kubota BX2350 with a 0.9 liter 23 hp. I知 not disappointed with the power of the JD but there is not as much difference as I thought in spite of the larger engine. In other words the larger displacement makes less difference than I thought.