Uses for a small Kubota diesel?

[Gasoline Fumes]

Originally Posted by Christ

RE: Clutch - Visit a Tractor Supply Co. store, they have centrifugal clutches. If you just want somthing simple to drive, that will do it, and they have them for like $30 that can handle 10 HP, IIRC.

You could use the governor, but engine speed control is much more likely to get you a desirable result. If you have enough gears, of course, or a CVT pulley, that will net you better results than even a throttle control would, as you could run CVT into a normal gearbox, which gives you basically Infinitely Variable ratios. (IVT).

If you don't mind using belts, and you are any good at fabrication, you can make a CVT pulley with V-belts and pulley cogs. If you want to see one, go to any place that sells MTD tractor parts, and ask them for a "transmission pulley" or CVT pulley. They call it both.

It's a double cone that slides in the middle of a wide standard pulley, which changes the open diameter on either side of the double cone. If one side is input, and the other is output, you have variable drive ratios. It's a simple "hydrostatic" transmission setup that MTD and Craftsman used to use, and may still be using.

What RPM do the centrifugal clutches engage at? I thought it was 2000+ RPM. Can the cheap ones be taken apart to replace the springs?

Thanks for the CVT pulley tip! I'll start by looking next time I'm at the junkyards. Plenty of mowers there.

How efficient are belts compared to chains or gears? I'd think belts have a lot more friction.

[Gasoline Fumes]

Originally Posted by dcb

Drive the wheels with a belt, and lever to control the tension on the belt will get you started too, via idler pully. That is how my 3.5 hp snowblower worked.

I've thought about a belt clutch, but I'm concerned about belt life if it's used too often. It's definitely the easy way.

[Christ]

Are you close to Binghamton? Gary's U Pull It has lawnmowers and fork lifts all the time that you could rob parts from.

The CVT pulleys, you can change the stall speed a couple of ways - You can either change the spring (it's a collar spring that's brazed together on the ends) or you can drill and re-weight the weights. I personally prefer using heavier weights than changing springs.

The key is to keep all the weights the same, or within a few grams. You disassemble, remove the weights, drill the bottoms of them about 1/2" deep x 1/2" diameter, and start filling them with either molten lead or something similar (Shot will work, as well, with tape over it for a short time, just to test). Make sure your holes are all in the same places on the weights, and keep them within a few grams of each other, for best results.

Obviously, a heavier set of weights = more centripetal force applied to the spring and better grip on the clutch's outer pulley.

So, yes, you can rebuild the cheap ones.

[Gasoline Fumes]

Originally Posted by RobertSmalls

Oh, I love data.That is a super-flat BSFC curve. I guess that should be expected from this sort of diesel, though.

The tragedy here is that the BSFC is consistently underwhelming. 210g/HP*hr is the same as 282g/KWh for the diesels you'll find here, or 277g/KWh for the gassers. Bottom line, at 27.8% efficiency, this Kubota is about as efficient as a garden-variety engine with fuel economy gearing, but much less efficient than any of the special engines out there - TDI, lean burn, Prius.

I like the idea of an underpowered, efficient small diesel for cruising, plus a large gas engine for accelerating, hill climbing, etc. However, this is not the correct engine.

What are ways to increase the BSFC of a diesel? Due to a very tight budget, it's this Kubota, a Mercedes-Benz 5-cyl turbodiesel or a Suzuki/Geo 3-cyl.

[Christ]

Go w/ the MB 5 cyl TD motor. You'll appreciate it in the long run. Also, the 3 cylinder engines can be had for like... $100 or less on good days. Most people that have them and want to sell them only want to sell them because they have the "4 cylinder" mentality... funny that the G10 and G13 only had like a 4 HP difference, though. Remember, it's got more cylinders, it's got to be better.

[Gasoline Fumes]

Originally Posted by Christ

Are you close to Binghamton? Gary's U Pull It has lawnmowers and fork lifts all the time that you could rob parts from.

The CVT pulleys, you can change the stall speed a couple of ways - You can either change the spring (it's a collar spring that's brazed together on the ends) or you can drill and re-weight the weights. I personally prefer using heavier weights than changing springs.

The key is to keep all the weights the same, or within a few grams. You disassemble, remove the weights, drill the bottoms of them about 1/2" deep x 1/2" diameter, and start filling them with either molten lead or something similar (Shot will work, as well, with tape over it for a short time, just to test). Make sure your holes are all in the same places on the weights, and keep them within a few grams of each other, for best results.

Obviously, a heavier set of weights = more centripetal force applied to the spring and better grip on the clutch's outer pulley.

So, yes, you can rebuild the cheap ones.

I'm about 2 hours North of Binghamton. I usually go to the Pick-n-Pull in Auburn or Trout's in Waterloo.

OK, weights over springs. Makes sense.

[Gasoline Fumes]

Originally Posted by Christ

Go w/ the MB 5 cyl TD motor. You'll appreciate it in the long run. Also, the 3 cylinder engines can be had for like... $100 or less on good days. Most people that have them and want to sell them only want to sell them because they have the "4 cylinder" mentality... funny that the G10 and G13 only had like a 4 HP difference, though. Remember, it's got more cylinders, it's got to be better.

I was half kidding about the Merc engine, it's way too big for what I want to do.

G10 makes 55 HP.
SOHC 8-valve G13 makes 70 HP.
DOHC G13 makes 100 HP.

I have some of each.
Besides more power, the 4-cyl is much smoother. The G10 is a pretty shaky engine.

[Christ]

I love the G10s, though. So I was a little off on the power figures... :P Still, the perception there is that the 4 cylinder is universally better. I've driven both, and I have to beg difference there.

I love the 3 cylinder because it's a super-mouse. It's got a decent torque curve that makes it feel "larger than life" for it's size.

[Gasoline Fumes]

I love the G10 too. I'm working on two '94 Metros. One keeps its G10 and the other gets the DOHC 4-cyl engine.

[bgd73]

Originally Posted by Gasoline Fumes

I have a 4.5 HP Kubota diesel engine (EL300-AR). It was originally from one of those flashing highway arrows. What should I do with it? I saw it on craigslist earlier this year and couldn't say no. I was thinking bike or trike, but that might never happen. I could make a generator, but that's no fun to ride.

It's tempting to run it on WVO, but I'm not sure how tolerant it is of that stuff.

A diesel with 4.5 hp..
what is the torque number?
I remember driving a tractor called "suzue", little 2cyl AWD diesel. That had a crazy low hp number, but could pull the truck out of a field, and run pto in what looked like an 8 foot wide triple bladed bush-hog lawn cutter type deck. One of my first lessons about numbers written, about types of engines in the power dept..
HP is a loser.
Alot of power there, its called torque...