Diesel Swap?

[JoeyRig 6]

Hello everyone,

 

I'm knee deep into a C120 build, that I've swapped a 520H swept axle and gear reduction steering onto. As she sits right now, I have a pretty rough, but running, K341 for power.

 

However, with a few (relatively) cheap diesel motors for sale around me, I'm starting to think. There's more than a few 2 and 3 cylinder kubota diesels in my area for sale that have piqued my interest. I also see that some Yanmars and Kohlers are for sale online. I've read more than a few threads here and other forums about diesel swaps but they're more the smaller 6-8 HP range. 

 

I guess my question right now is does anyone have any experience with some of these 1, 2, or 3 cylinder diesels and is it worth the swap? I have about 5 acres that needs to be mowed and I was kind of hoping of fitting a 60" deck on there. Other duties would include hauling trailers loaded with landscaping debris and pulling smaller logs and stuff out of the brush. 

 

Also would the frame and 8-speed be able to handle a diesel?

 

I'm torn because while I love the simplicity of the kohler k's my block's fins are pretty rusted and pitted, and the flywheel is actually cracked so I'm guessing she was ran hard. I don't want to go through a whole rebuild only to have it fail later down the road. Also there's just the cool factor of a little diesel tractor.

 

Any help would be much appreciated.

 

Thank you.

[ebinmaine 69,600]

@Achto is the one to call here... 

[SALTYWRIGHT 859]

I HAVE DONE 2 DIESEL SWAPS.  A 10 H/P IN A 417-8 AND A 6 H/P IN A 1054. VERY EASY SWAP. THE 10 H/P HAD MORE POWER THAN THE 17 H/P I PULLED OUT THAT IS WHY I USED A 6 H/P IN THE 1054.

DIESEL POWER IS NOT THE SAME AS GAS.  WHERE ARE YOU IN CT ?  I AM IN NORWALK, CT.

[Skipper 1,789]

Key here is that you want to run a 60 deck.

 

I have a twin diesel in mine. It makes about 30hp at full load. Plenty power, but really not a bit too much for the 60".  I know I'm probably going to be shot for this, but really, you can't within reason, pile too much hp on that 60". It will just be able to run faster while mowing, go thru anything, and it will still do a fine cut. Not sure I would try running a 60" with one of the smaller single cylinders at all. If you want to run a 60", go for at least 20 or more hp is my  No such thing as too much power IMO, but there sure is such a thing as too little............... Especially with a manual trans, where you can't do "on the fly" adjustments to speed.You probably want to mow in highest gear, and you need some muscle to swing that.

 

Be aware of the size of the engine too. If you still are going for belt drive and side pto setup, then a 2 or 3 cyl inline will stick out a crazy amount on the left side. I would suggest a v twin, and even that is very wide too.

 

Also I hope you are contemplating some sort of hydro or electric lift, as that 60 deck is really heavy to handle with arm power.

 

Not trying to discourage you here, but honestly, in that tractor, I would go for a big single which are typically in the 10-15 hp range, and be OK with a 48" deck. MUCH simpler install too. Basically plug and play. (with a few little things done like electric pto and so on) 

Edited October 29, 2020 by Skipper

[Achto 28,138]

Because of the lay out of a Wheel Horse, a single cylinder air cooled diesel would be the easiest swap. The power that I have from my 10hp Hatz diesel is kind of unbelievable. I have yet to find enough work to make it pull on the governor. Pulling a 10" Brinly plow from lighter to heavier soil you will hear the tranny start working harder as you enter the heavy soil, but the engine never changes tone.

 

If you find a 2 cylinder that you can mount side ways that may work out as well. Fitting a 3cyl Kubota would be a bit of a challenge You would most likely have to lengthen the frame to make room for the engine & radiator to mount inline with the tractor. Then there would be the challenge of turning the rotating power 90 degrees so that you could run a belt to the transmission. This could be done with a right angle gear box which would again lengthen your power unit. Not saying that it can't be done but it would be a challenge,

 

One other thing to keep in mind is that a 60" can be hard on the frame of your tractor. I have seen some 520 frames crack where the foot bar passes through the frame on tractors running a 60" deck.

[Lee1977 6,909]

I don't think you can put a big diesel in a C-120 with out a lot of major modifications. I have an 18 HP Briggs Vanguard in my C-120 and there isn't any room left.  I'm not saying it can't be done but there will be a lot of changing to make it work.

Edited October 29, 2020 by Lee1977

[JoeyRig 6]

@Achto Thank you! I assumed that the 2 and 3 cylinder diesels would need to be mounted that way, but its good to hear someone confirm that.  I guess I'll have to start getting some measurements and seeing how everything will fit. And yikes, maybe the 60" isn't the way to go, in terms of power and frame strength.

 

@Skipper Thank you! Between you mentioning the power, and @Achto mentioning cracked frames maybe the 60" is out. The only issue is that all the single cylinder air cooled diesels are absurdly expensive. There seems to be a lot of cheaper 2 and 3 cylinders around. Gonna have to start taking some measurements and see how everything will fit.

 

@SALTYWRIGHT Thank you! Which 10 horse did you drop in? Just curious as that was kind of what I was leaning towards but they are just so expensive. I'm in central CT, around Hartford. 

[Lee1977 6,909]

I check into a diesel last spring. I was looking at a Hatz  1B50E the only 10 HP Hatz sold here in the US around $3500. I decided I'm too old to get the use out of it.

 If your a young fellow it might be the way to go. A later model Wheel Horse with the gas tank under the seat will provide a lot more room then the C-120 all the frames are

close to the same with just a minor change the C-series through the 300, 400 and 500.series. They could all use some reinforcing  with a 60" deck. It would be easer to do it before it broke.  

Edited October 29, 2020 by Lee1977

[Achto 28,138]

7 hours ago, JoeyRig said:

The only issue is that all the single cylinder air cooled diesels are absurdly expensive.

 

There are some Yanmar knock off's that are not too bad on price.

 

https://www.ebay.com/itm/10HP-Diesel-Engine-411cc-Vertical-4-Stroke-Single-Cylinder-72-2mm-Shaft-Length/264179277313?hash=item3d824fde01:g:7u8AAOSwbwFe2Ixp

Edited October 29, 2020 by Achto

[shallowwatersailor 3,214]

I owned a C-105 that was converted by another member. It has moved on to a different member! The Carroll Stream 10hp was a perfect fit on a Black Hood only needing to be raised about 1/2" at the hinge..

[Goofey 89]

If I understand those engines right. Then that is the type skipper talked about being available in 14 hp too with electric start and all. Sweet. That thing fits nicely.

[Goofey 89]

1 hour ago, shallowwatersailor said:

I owned a C-105 that was converted by another member. It has moved on to a different member! The Carroll Stream 10hp was a perfect fit on a Black Hood only needing to be raised about 1/2" at the hinge..

 

How was that on power, and how did it hold up?

 

[JoeyRig 6]

@Achto The only reason I haven't jumped on one of the clones is I've heard horrible things about long term reliability.

 

@shallowwatersailor How was the carrol stream motor? I actually looked at that one before, but honestly it looked like a clone.

 

Also, I found two Kubota D722E motors near me for a little south of a grand. One is running, the other is for parts. They're relatively small (17x16x22" tall) 3 cylinders, around 20 HP, that I'm considering. 

I know that diesels are inherently more expensive and harder to work on, but does anyone have any experience with these motors? I just want to make sure I'm not buying anything that's going to be super expensive to upkeep in terms of parts and labor. Are these smaller diesels outside the scope of a shadetree wrench monkey?

 

Also, thanks again for all the help, this is exactly why I posted here, for some advice and guidance and y'all didn't disappoint. 

[71_Bronco 1,072]

Here's my 8-speed trans, 60" Deck, Diesel tractor 

 

This one is roughly 18HP, 3 cylinder, with a manual PTO (belt tension type).

 

The only thing I might add, is if you decide to go with a 60" deck, then make sure you get a nice one to start and keep up on it. I don't think they are as plentiful as say the 48" decks. This tractor use to mow about 5 acres, and my dad had a twin to it that he would mow about 8 with. This one is now babied with my 1/2 acre flat yard lol.

 

[shallowwatersailor 3,214]

On 10/29/2020 at 12:47 PM, Goofey said:

 

How was that on power, and how did it hold up?

 

 

It was definitely strong. I didn't use it enough to really wear it out. 

[shallowwatersailor 3,214]

10 hours ago, JoeyRig said:

 

@shallowwatersailor How was the carrol stream motor? I actually looked at that one before, but honestly it looked like a clone.

 

 

It was a clone of the Yanmar engine. Early examples (not Carroll Stream) did fail prematurely but reliability improved when they became a more mainstream replacement engine. Of course there can be lemons by anyone. I am not sure of parts availability these days. Also the glow plug is not in the cylinder but in the intake. Cold weather starting may or may not happen.

 

Diesels are a bit different than a gasoline equivalent. The fuel system plus the higher combustion pressure can be a notch above a shadetree mechanic. I was an Engineman in the CG and was trained to maintain diesel engines. With regards to the Kubota engines, my opinion is that the Yanmar single is all the Wheel Horse can handle. 

[wh500special 2,244]

The three cylinder engines would be nice, but you need to be clever to find a place to position the radiator.  

 

you can find inline twin-cylinder, air-cooled Diesel engines from Hatz and probably others.   I have one collecting dust I thought would be perfect for a c195. 
 

If you’re determined that to make the water cooled versions work, This is a link to an awesome solution:

 

best wishes,

steve

[tom2p 2,394]

On 10/28/2020 at 8:52 PM, Skipper said:

 

Not sure I would try running a 60" with one of the smaller single cylinders at all. If you want to run a 60", go for at least 20 or more hp is my  No such thing as too much power IMO, 

 

Not trying to discourage you here, but honestly, in that tractor, I would go for a big single which are typically in the 10-15 hp range, and be OK with a 48" deck. MUCH simpler install too. Basically plug and play. (with a few little things done like electric pto and so on) 

agree 

 

48" deck would be better than a 60" deck for a single 

 

often if not typically the time between cuts can stretch out when cutting a large amount of grass ( 5 acres in this case ) - so more horsepower is your friend because the grass could be especially tall / thick 

 

[JoeyRig 6]

So now I've found a Z482 near me that I'm interested in. Lightweight, and small enough that I think I could fit it crossways without a gearbox. Its still a two cylinder but only 12ish horse. 

 

The 60" deck is definitely out so I'm thinking of just keeping my 42" or a 48".

 

I'm thinking I ran it with the 12 Horse k301 and it did fine, so I think a 12 Horse diesel should do the job as well. Thoughts? 

 

Thank you!

[ebinmaine 69,600]

8 minutes ago, JoeyRig said:

12 Horse diesel should do the job as well.

 

The other folks might be able to answer a little more accurately.

 

In the heavy trucking world that I'm in a diesel engine of comparative size to a gas engine will make TWICE or sometimes as much as FOUR TIMES as much torque. 

 

i'm only taking a little bit of an educated guess here but i'd say at 12 horse two cylinder diesel is probably going to make around the same amount of torque as a 16 to 20 horse gas engine. 

[pfrederi 18,128]

1 hour ago, JoeyRig said:

So now I've found a Z482 near me that I'm interested in. Lightweight, and small enough that I think I could fit it crossways without a gearbox. Its still a two cylinder but only 12ish horse. 

 

The 60" deck is definitely out so I'm thinking of just keeping my 42" or a 48".

 

I'm thinking I ran it with the 12 Horse k301 and it did fine, so I think a 12 Horse diesel should do the job as well. Thoughts? 

 

Thank you!

 The Kubota is 22" tall a K-341 about 17"  Hood scoop??? Big hood scoop.

[tom2p 2,394]

5 hours ago, ebinmaine said:

 

The other folks might be able to answer a little more accurately.

 

In the heavy trucking world that I'm in a diesel engine of comparative size to a gas engine will make TWICE or sometimes as much as FOUR TIMES as much torque. 

 

i'm only taking a little bit of an educated guess here but i'd say at 12 horse two cylinder diesel is probably going to make around the same amount of torque as a 16 to 20 horse gas engine. 

eb - common if not conventional wisdom - but in the case of some small diesel engines might not be the case ... small engines used in the compact Kubota tractors at least (?)

 

apparently the smaller Kubota gas engines outperform the Kubota diesel engines ( horsepower and torque ; same size *** )

 

maybe someone with a compact Kubota tractor can comment 

*** the models I'm referring to are the D600B 600cc 3 cyl liquid cooled diesel and WG600B 600cc 3 cyl liquid cooled gasoline

 

Edited November 3, 2020 by tom2p

[lynnmor 7,459]

4 hours ago, ebinmaine said:

 

The other folks might be able to answer a little more accurately.

 

In the heavy trucking world that I'm in a diesel engine of comparative size to a gas engine will make TWICE or sometimes as much as FOUR TIMES as much torque. 

 

i'm only taking a little bit of an educated guess here but i'd say at 12 horse two cylinder diesel is probably going to make around the same amount of torque as a 16 to 20 horse gas engine. 

 

Of course a diesel making twice the torque and having the same horsepower will be turning half as fast.  Claims that diesel will outperform gas usually are from those that aren't running full throttle.  Keep in mind that those torque and horsepower specifications are measured at full throttle.

[tom2p 2,394]

5 hours ago, JoeyRig said:

So now I've found a Z482 near me that I'm interested in. Lightweight, and small enough that I think I could fit it crossways without a gearbox. Its still a two cylinder but only 12ish horse. 

 

The 60" deck is definitely out so I'm thinking of just keeping my 42" or a 48".

 

I'm thinking I ran it with the 12 Horse k301 and it did fine, so I think a 12 Horse diesel should do the job as well. Thoughts? 

 

Thank you!

 

Z482 super mini specs are impressive

 

http://www.dieselenginemotor.com/kubota/supermini/Z482

 

.

[Goofey 89]

On 11/2/2020 at 8:27 PM, JoeyRig said:

So now I've found a Z482 near me that I'm interested in. Lightweight, and small enough that I think I could fit it crossways without a gearbox. Its still a two cylinder but only 12ish horse. 

 

The 60" deck is definitely out so I'm thinking of just keeping my 42" or a 48".

 

I'm thinking I ran it with the 12 Horse k301 and it did fine, so I think a 12 Horse diesel should do the job as well. Thoughts? 

 

Thank you!

 

Have you pulled the trigger on something?