Diesel Cub?

wdbtchr

Active member
I'm new to the club and at the risk of raising the ire of purists, has anyone ever repowered a Cub with a diesel engine. The engine in my '58 Cub is shot, knocking, burning oil, low power. It has had new rings and bearings put in it twice, so I'm thinking rebuilding my be a problem. It would be nice to have a little more power also. Should I run and hide now?
 
Goodness! Why would anyone complain about a diesel conversion? A few members have re-powered cubs with novel power sources such as this:

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As we say around here, "It's your tractor, you can do what you want."
 
Ralph can sell you a good used engine for$500.00 Shipping might kill you, depending where you are. (RALPHS CUBS is a site sponsor,located on the home page). Ed
 
wdbtchr:

First,
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to the greatest forum on the internet, and to the Cub Family. You will find that all the folks on this forum are kind, helpful and just full of Cub info and knowledge. They also happen to be the finest folks I have ever met :!: :D

wdbtchr":34tvg116 said:
I'm new to the club and at the risk of raising the ire of purists, has anyone ever repowered a Cub with a diesel engine. The engine in my '58 Cub is shot, knocking, burning oil, low power. It has had new rings and bearings put in it twice, so I'm thinking rebuilding my be a problem. It would be nice to have a little more power also. Should I run and hide now?

One thing you will learn quickly here is that there are many things that our members will do to their Cubs.. just because they can, or the idea seems like fun or to make it more efficient.

BD has posted Rick Prentice's Cub Harley with a 6cyl mill, Rick also has built a BackHoe Cub which is an awesome Cub to see.. and George Willer has built the very first and probably only great Tricycle Cub. Another contributor built the SweetHeart Cub and you can see that in the Cub Gallery on the main page of this site...

So as far as purists.. well we are not really purists in the commonly held view of the statement. We just love our Cubs.... and we know that we can play with them and be creative, we can make em Trailer Queens if we wish, and we can make em just work tractors.. it is all correct.

The only admonition that I would have, is that if you do go that route.. well,
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and a written documentary on what you did. And if you just replace the engine with another one, say from Ralph, JP or TM.. then pics and a narrative of that procedure would be beneficial to the rest of the forum as well.

Welcome to the Family :!: And have at it :!: :wink: :D :D

Ok, so here is the spiel
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:

I would suggest that you read this thread: New Members and Visitors, Please READ Prior to Posting. There are many great links to informative pages such as the ATIS FAQ's 1 and ATIS FAQ's 2, The Best of H.L. Chauvin who has written very interesting articles on troubleshooting common problems with your Cub. One of the other projects we have been working on and it will be a continuing effort is the How To Work on Your Cub - Maintenance Tips and Techniques. This the the place to go to get all the quick links to some very good articles written by many members of the forum on solving some of the problems we encounter as we repair, maintain and up-grade our Cubs. Keep looking for this to grow.


Also, you might want to visit the Cub Manual Server as there is tons of info on servicing, maintaining and re-building your Cub. In addition to this basic information, there are also a number of other useful tools available on the server. There is the Specialty Services page which has contact info for neat stuff like getting your seats recovered, buying quality Decals, Serial Number tags and a host of other neat items. Also there are the Parts Pages - both Used Parts Suppliers and New Parts Suppliers pages with links to quality dealers. I am always looking for YOUR favourite dealers for New and Used Parts to include here. These pages are intended to complement our Official FarmallCub.com Website Sponsors:
I would also recommend that you visit Binder Books and purchase the three most important manuals you can own for Maintenance, Repair and Rebuilding your Cub. These are the Owner's Manual, the GSS-1411 Service Manual and the TC-37F Parts Manual. Although they are available on the Cub Manual Server, it is better if you also have your own paper copy. Binder Books is the only Authorized IH Publication Reprint House and they have the best quality manuals available. Most other's are not of the same quality. Just a personal thought here, the I&T Shop Manuals, although helpful in some areas, really are not sufficient for the job. If you wish though, they are good additional reference works.

IF you really want to get the skinny on all things Cub, might I suggest you get a copy of Ken Updike's Farmall Cub and Cub Cadet's :?: . While you are at it Original Farmall Cub and Cub Cadet is Ken's latest addition to the series. Along with Guy Fay's Letter Series Originality Guide, these are three must have's in anyone's collection.

In addition to the above information, don't forget to check out the various articles that are available to help with your Repair, Restore, Rebuild or just your Maintenance Projects. There are a number of sub pages such as Electrolysis or Rust Zapper's, Maintenance Tips, Jigs and Techniques, Implement and Part Sketches and of course the Paint, Decals & Other Finish Questions which has the Paint Chart and the Paint Committee Decisions links.

Oh, and while the program still lasts.. you might want to check the Announcement: Navistar Free Gas Cap Offer - On-Line Form thread at the top of the Cub Forum and send away for the new style safety cap before that program runs out as well.

I truly hope that you enjoy your Cub and that you will be a frequent contributor to the forum. Again,
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to the Cub Family
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:D
 
wdbtchr
I think you should go for it :D If I could get my hands on a nice little Kubota 3 cyl diesel engine, I'd do it, no questions asked. I think it would be a nice combination, just right for the cubs driveline. I'd even like to find a Kubota front axle to make it 4wd :shock:

Rick

(thanks guys for the kind words :wink: )
 
Rick(billyandmillie)":zh197gma said:
wdbtchr
I think you should go for it :D If I could get my hands on a nice little Kubota 3 cyl diesel engine, I'd do it, no questions asked. I think it would be a nice combination, just right for the cubs driveline. I'd even like to find a Kubota front axle to make it 4wd :shock:

Rick

(thanks guys for the kind words :wink: )

Rick,

You should have a heart to heart with Gary Dotson. He's been running and working his Cub at over 3000 RPM, hoping it will blow so he can do the conversion. The C-60 is holding up. :( He has the diesel engine. I think it's a 3 cyl Kubota.
 
Actually, the Kubota engine that I have is a small 4cyl. (800 cc) Displacement wise, it's almost the same as the c60, but much smaller externally. I'd love to get going on this project, but it seems that other stuff keeps getting in the way.

There are a few complications in this conversion, but I'm sure it can be worked out.

Rick, we need to talk about this, I may need some of your skills since I have very limited machining facilities. Maybe we can talk at Cub-fest.
 
Well this has certainly been a pleasant surprise. :D I belong to a couple of Military Vehicle groups that are very upset when someone mentions just about any kind of change from original. I have four military vehicles that very from stock to fairly modified, not by me but by the local fire dept I got it from.

I got the idea for the deisel conversion for two reasons. Gasoline going bad between fillings and a catalog I got from Surplus Center in Lincoln, NE advertizing several sizes of new Kubota deisel engines.

I'm a fair to middlin' shade tree mechanic, but not sure if I could pull this off. Not like putting the 327 in my '50 Chevy pickup, the clutch was a bolt-up match. I was curious it anyone else had tried something like this.

This Cub had been in the family since 1964, my dad was the 2nd owner. Thats how I know it's had two rebuilds already, and I also have the original set of manuals it came with. I rebuilt the final drive and pto a couple of years ago so it's as strong as new. I rember mowing the fields with it when I was in high school when it was still new. I always thought it would be so much better with just a little more power. Nows my chance.

Time for some research.
 
As antique tractors go, Cubs are fairly plentiful, with many that have been, or are being restored. It's OK to go the other direction occasionally. I wouldn't consider it on my Cockshutt 20, as they are in short supply. The other day, I saw a Cub puller, with a Wisconsin V4 on Ebay. That was interesting too. I think it's far worse to paint one green & yellow!
 
wdbtchr, I haven't had time to look at a Kubota engine yet, but the biggest obsticle will be attaching the front end of the cub. On my Chrysler V-6, the adapter plate between the engine and torque tube was fairly simple. I also just turned an adapter hub on the lathe to fit the v-6 crank and accept all the cub clutch/pressure plate/flywheel parts. The 3.0 liter V-6 was used in lots of different Chrysler vehicles so it had multiple mounting holes all down both sides of the block. Since the Cub uses the engine block as the frame in that area, you need to study the Kubota engine for strength. I decided the front end of the Cub wasn't going to just bolt to the front of the V-6, so I had to make a cradle for the front end to bolt to and then the v-6 basically is setting inside that cradle. My other obsticle was the intake arrangement on the v-6. I had to scrap the chrysler set-up and make a whole new intake that uses a Harley 2barrel front draft carb(only thing I could find to fit under the cub hood :shock: ). Plus the hood is raised about 2" on "Harley". You'll notice the 2" strip under the grille. I had to do the same thing to the dash.

The Kubota sure seems like a nice engine, as long as that front end of the Cub can be adapted to it.

Keep us posted on your progress.

Gary, we'll definetly talk at Cubfest :D

Rick
 
The Kubota has multiple bolt holes along the sides. I think it will be fairly easy to fab. a cradle from flat stock. I think the biggest challenge may be the starter, since Kubota and all the other small diesels I've seen are on the wrong side. I'm hoping to not have to resort to the method you used on Harley. I realize that you had virtually no choice in the matter, you sure weren't going to hand crank it! I'm considering torque tube mods to put it on the other side.

Yes, we'll talk at Fest
 
Gary wrote:
I'm hoping to not have to resort to the method you used on Harley

Oops :shock: , that slipped my mind about the starter. That was another challenge to figure out with the v-6 :D

Hurry up wdbtchr, we need some ideas :D :D

Rick
 
The idea of using a Kubota for repower has taken on new meanings, it has moved from future project to urgent. I installed a new radiator and did my regular spring maintence in preperation for mowing the fields.

Mower was working great, rebuilt last year from two parts Cub 22 mowers. Power still low, buring oil still, but with a new developement. On the torque tube about where the clutch is there are two casting mounts. Don't know what they were intended for, but the holes were pluged I assume from the factory with wooden dowels and painted over. One of the lower plugs fell or blew out and white oily looking smoke was comming out the hole, seemed to pluse especially when the engine was pulling hard. No oil or antifreeze leaking just smoke.

After mowing for about 3 hours, one of the ears the fan mounts on broke off. The fan went through my new radiator. It doesn't seem worth trying to find a front cover for this worn out engine.

I haven't found any information on the Kubota flywheel or adapting the Cub clutch to it. Also there's the problem of providing some kind of Hydraulic pump for the lift. Don't know how the starter on the Kubota engine is mounted, but wondered if it couldn't be reversed and mounted on the right side like the Cub starter.

All this thinkin' is making smoke come out of my ears. Any ideas where I might find measurements on Kubota engines?
 
In farm show magazine Volume 29 no 2 in 2005 there is an article on page 38 of a guy doing this very thing to a 184 lowboy like mine using a Yanmar 3 cyl diesel. He had to rework the flywheel as it was different. I admit I have thought about contacting him for more info with the trouble I have had with mine but, I will see if I can't straighten out my issues first. I didn't even want to mention anything of the sort on a board dedicated to Cubs for fear of finding crosses burning in my front yard. LOL :lol: This is a cool thread.
 
Check ebay, there is a seller or sellers that often have small used Kubota engines available. They import used tractors and engines from Japan. They will likely have a source of manuals and info.
 
A conversion on a 184 could be a lot easier since there's a frame to support the radiator and front end that the F-Cub and Lo-Boy don't have.

Don't worry about burning crosses... you're among friends here. :lol:
 
I found some dimensions on the Kubota engine at: http://www.dieselenginemotor.com/drawings/d722-e.htm

Looking at pictures of the engine it looks like the plate on the back of the engine is bolted on and appears to be reversable, would move the starter to the right side of the engine. Don't know if it would match the cub mount, but modification would be simple even if you had to fabricate a new plate to move the starter up or down slightly.

I was wondering if it was possible to use the Cub clutch disc with the Kubota pressure plate, would eliminate the need to drill the Kubota flywheel to match the Cub pressure plate.

Which leads to the question, does anyone have a Cub flywheel laying around or have the dimensions of it? I need to know the dia of the flywheel. My Cub is down on the farm and I haven't taken it apart that far yet. I have an old disc, it's 6 1/2" in dia with 15/16" dia with 10 splines.

I'm thinking of trying to line up the alternator with the crank pulley and mounting an electric radiator fan to get it running so I can finish owing the fields. Conversion can be a nice inside project for the winter.

Thinkin', always thinkin'.
 
On the right side of the Kubota engine, there is a very nice & very necessary fuel injection pump located where the starter would need to be!

You could probably mate the Cub disc with the Kubota pressure plate, but the input shaft won't reach it. My plan calls for an adapter hub to mate the Cub flywheel to the Kubota crank. I did a little rough measuring at one time & if I remember correctly, it would need to be about 1 1/4" thick to put the flywheel in the correct location.

The plate on the back of the engine needs to be replaced with one fabricated to fit the Cub bell housing.

There are several obstacles that will require consideration, but that's what makes it fun. Rick Prentice & I have discussed this & most of my plans are just the way he put the V-6 in Harley. Of course, he had other concerns as well. There was no way he could mount his starter to the engine, so he cleverly used the PTO, that wasn't going to be used anyway.
My hope would be to make it look as "factory" as George Willer's Trike.
 
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