Super 446 Build- Diesel Swap

Yes that is the pin that I replaced. While it helped quite a lot to pull it tight, the channel itself the front axle is in, it is still sloppy on the left and right sides of the frame. It is almost like when they welded the frame that day, they got a little carried away with pulling it tight to the frame cutout.

I'm not sure what you're referring to for "primer remover".

Ok so to bring this post close to current, I will start the engine portion.





I will be using a Yanmar 3tne68 3 cylinder diesel. I came across it locally for $400. It was a sailboat generator. The generator portion shorted out and they pulled it from the sailboat.



Two reasons why I jumped on this.... well three. #1 it was cheap lol. Most engines like this go for $1500 to $4000 bucks used in various conditions. #2 it only had 500 hours on it. The interior of the engine looks brand spanking new. It's honestly truly unbelievable how clean it is inside the motor. #3 being a generator it was set to run 1800 rpm. So no young kids reving the crap out of it, or doing stupid stuff. It lived a nice quiet and easy life in the bottom of a boat.





The reason I went diesel is well.... I wanted too.... and more power. The 3tne68 runs around 20hp and can make more. I do plan on eventually running a turbo. It is 784 cc weighs about 175 lbs and turns the normal 3600 rpm. John Deere used this same engine in a 2500 and 2653 greens reel mower. They also used the identical block but smaller cc 3tn66 and larger cc 3tna72. They are the same exact engines just with smaller and larger bore and strokes. These were used in the 330 332 430 455 655 755 855 and many others. I honestly didn't know JD had so many small tractors with the same diesel engine.

Before anyone says the hydraulics can only use so much power blah blah blah..... I understand that. That is with the stock hydraulic system which I will NOT be using. The only two items staying stock are the TCV and the hydraulic motor. Either way I will address this in a future post on what I'm doing for the hydraulic system.

Anyway... the 3tne68 fits in better than you could ask. Everyone says it can't be done without butchering the hood and lengthening the frame. This is simply not true. THERE WILL BE NO CUTTING THE HOOD AND NO LENGTHENING THE FRAME. That was my absolute #1 rule for this build. It must appear stock. I don't want a hack job. I want this tractor to look like it rolled off the assembly line with a diesel.

The 3tne68 oil pan sits nicely down inside the frame rails. I will have to weld a drain on the bottom of the oil pan. It is currently on the side in the frame rail and inaccessible. The flywheel will sit down into the frame perfectly as well at the lowest point. I do not plan on cutting any clearance as it will be unnecessary.



With changing the thermostat housing, I was able to have about 3/8" hood clearance. So that's even better.



Now two things you don't see in the pictures.... #1 I will not be running the front pto drive and #2 the mid lift cylinder is being changed out for a john deere cylinder. You can see the mount I've already welded in the cross brace for the mid lift cylinder. By changing the mid lift cylinder it allows me to safely run more hydraulic pressure and a stronger built cylinder than OEM. I've also gained a inch of stroke to 4" instead of the Case 3". The rock shaft will have to have the mounts cut off and rewelded on the bottom to clear the oil pan.

The one problem will be is the brake pedal. It will have to be cut off inside the dash tower. I am unsure yet how I want to go about addressing that. I have a few ideas but until the engine is mounted, I'm not going to do anything yet. I'm thinking about notching the dash tower possibly or making an arm that slips inside to keep the original function of the parking brake and travel lever release.



Here are a few more pictures of it sitting in the frame. I have a good 8" from the water pump snout to the front of the grill. This is with shifting the hood forward a bit but you can't even tell. The hood still overhangs the dash roughly 3/8" and still looks nice. This might not be permanent. I'm going to use a Austin Mini radiator and that will be here the end of the week. So depending on thickness and mounting the oil cooler, the hood could very possibly stay in the stock position. It all depends on a fan.















So from what I'm seeing with other diesel swaps (which there are very few) the kubotas are larger in length and width. The yanmar is taller but that was negated by it sitting down in the frame rails. I've just seen a few kubota swaps and there was definitely hood and frame cutting. So maybe that is why everyone told me it couldn't be done, but with this yanmar...... you can see it most certainly can be done.

I also had to remove the parking brake setting bar from inside my frame rails. I moved it to just outside the frame rails. I remade it a little longer and from a little thicker steel, and routed it through a slot in the front face of the footrest panel. I relocated the factory tension spring to up underneath the footrest panel. For setting the parking brake, I added an extra "inner" brake pedal. It works really smoothly.

The horizontal bar has a cog cut into it such that when you lift up on the rearward end of the bar while the pedal is pushed all the way down, the cog in the bar clicks up and engages against the top of the slot. With the bar thus engaged, the brake pedal is locked in the full down position.

The "extra' inner pedal applies tension to the visible "lifting" spring as the brake pedal travels forward. So if you put your foot on that upper/inner pedal and push down, you'll hear a click at the end of pedal travel, the the parking brake is now set.

If you then push on the "normal" pedal, you'll hear a click, and the parking brake is now unset.




If you wanted to go this route, you may need to upgrade your older style brake pedal to the newer style.

Bob

I am currently in the process of a similar build but with a Kubota D1105 diesel, I am in the final run of getting it driving under it's own power and plan to make more updates on it here soon. You can check my profile for previous threads to see what I had to do it it. I had a little more hack and slash to do to mine but it's what I had, all said and done I think I spent maybe $1000 on the engine including rebuild as I was looking at a similar route as this but the prices of even used diesel motors pushed me away. Glad to see I'm not alone in the pursuit of "big" diesel swaps, looks like you've done a much cleaner job than I have though and started with parts that are in much better condition.

Some things to note from my perspective on my build, may or may not be helpful for you:

1) Having a mechanical PTO for either the rear hitch or the middle is next to impossible. I have worked out a mid PTO idea but have yet to try it and for the rear there's just simply no room unfortunately without large amounts of fab and modification.

2) With these diesels they're far heavier typically than the stock Onans (not to mention significantly more torque-y) so I'd recommend some frame reinforcement at some point, especially if you are planning on adding a loader or sizing up the 3pt category. Also, the weakest link typically is the frame cross-section change by the brake drum (extensively covered on this site) and the front axle and mounting area (@bobneumann has a fantastic video on a new front axle build on his YouTube channel). The frame is roughly 10ga C-Channel which is strong but given enough twisting loads will yield pretty quickly.

3) With great power comes great responsibility... Curious to see what pump sizing you're planning on doing and what kind of attachments/valves you're going to throw on there. I have found the hardest design problem on mine has been the hydraulic routing and valve placement. Either way 20hp is a lot to play with in something that size and all hydraulic.

Thank you everyone for the compliments!!!!!

I'll use this post to address all the questions and then later tonight I'll post where I'm at with the hydraulic system.

Dundee- As for no front pto and mid lift... yes I do want to retain original functionality with the mid lift cylinder to do a few things. I want to possibly keep a plow on the front all the time. The case plow is actually pretty heavy duty compared to most other brands. I have the new style designed in fusion 360 but I need to find a place to laser cut and bend the brackets. I also would like to possibly run a middle blade like a road grader with tilt and pivot as well (hint to the 3 spool valve on the drivers side). So keeping a cylinder tucked up on the engine close to the original position will let me do that without have to redo everything. I do not plan on a loader at this point. If I was going to do a loader I think I'd just find a case loader and go that route instead. The Super 446 is going to stay more along the lines of a traditional farm tractor.

Bob- I have seen your post and do have it book marked. Your setup is something I have definitely considered. One thing I forgot to mention was I do want to do a individual rear brake setup. The website and posts by a gentleman named gator I believe is gone but I have started to source parts for it. So that might be a good way to go for the brakes.

Vigo- I will post more of the hydraulic system so far later tonight.

Ddude- I will definitely just be doing the rear hydraulic pto and maybe a front at some point as well. Not sure what I'd use on the front but you never know. That could be done two ways, off the 3 spool valve or just make up some lines off the rear pto valve. I don't think I'd run some front and back at the same time but who knows.

As far as frame reinforcements I do plan on doing something. I haven't seen anything on the rear of the frame, could you post a link? As for the front I have seen numerous failures while researching. My plan of attack is two fold. The diesel block is a very stout structure so what I plan on doing is kind of like a Farmall tractor. The engine will be part of the structure along with the frame rails.



I'm going to make a plate that will drop down in the notch where the Onan sat. It will get welded front to back and will hold the engine like a cradle. Then I'll have two flanges on the each side of the rear to bolt to the starter plate. The starter plate is roughly 1/4" and will work just like a engine mounting plate in say like a racecar.

Then I also would very much like to make a one piece plate that will run from front to rear. It will go over and around the front axle reinforcing that and the front attachment mounts as well.

Then on the bottom of the frame will be a flange, basically making one larger piece of angle iron front to rear. The only place it might cause an issue is around the brake drum. That side might have to be split into two pieces but I think it can be done.

It would be nice to tie into the 3 point plate as well.

So the main advantage to the Case tractors (as we all know) is the true hydraulic system. It is a great start to all kinds of custom attachments. What I'd like to do is have all attachments run hydraulically.

The one main thing I want to build using a 44" deck (that normally would go underneath) into a 3 pt brush hog. I have my '88 446 for normal mowing but I have a few areas on my property that is semi rocky with weeds and crap growing. Also my neighbors have a line of pine trees dividing our properties. The trees are on his side but have grown on my side and they won't trim them so there is all kinds of crap growing under them and I don't feel like driving my nice tractors under them to mow. So this will help by backing up under the trees. Aren't neighbors so wonderful?

A few other things are the stock tiller, a box blade with hydraulic top link cylinder and a hydraulic cylinder on one of the 3 pt arms for tilt. Depending on how the box blade works maybe a belly blade like a grader. I'm also thinking about a 3 pt bucket like @Lionel did on his tractor. That attachment is quite amazing. He has some amazing fab skills.

So starting from the beginning of the hydraulic system, let's start with the pump. I'm going with a SAE A pump for a more robust pump than the Uber expensive factory pump. I am going to step up on volume but not a lot. I'm thinking the .85 cu in pump from surplus center. That will be bit more than stock but nothing to crazy. Plus I'll be able to control the flow as I'll explain further in this post.

I have designed the lovejoy coupler in fusion 360 and just need to get it machined. It will bolt directly to the crankshaft sandwiching the flywheel. It will register off the flywheel just like the flywheel centers on the crank. I'm also stepping up to a L110 lovejoy due to the extra power and torque using lovejoy's safety factor. The pump connections will remain factory and in roughly the same location.







Next moving on..... all hoses were replaced with 100R17 hose rated for 3000 psi working pressure. The only factory lines still being used are the steel lines from the TCV to the motor. 5/8" hose for everything under pressure, and 1/4" hose for the mid lift and 3 pt cylinders. All hoses are also being covered in MSHA rated sheathing. Moving right along..... next in line the rear pto valve.

Now the tractor came with a rear pto when I bought it. Knowing that I was changing stuff around and also knowing the seals for that valve are super expensive, I sold it. I went with a chief valve that I added a 3 position detent on. The chief valve also has a power beyond port. That is a added bonus that I really wanted to feed the 3 spool valve on the dash tower. Agricultural quick disconnects were added to the rear pto valve.





Next the outlet for the rear pto goes back up the left frame rail to the flow control valve mounted on the left side of the dash tower. I cut a hole in the left side foot board just like the right side to aid in running the hoses cleanly out of the way. It then comes out of the flow control valve and goes right under to the TCV.







So as you can see I upgraded to the integrated holding valve and sold separate holding valve to save space. This did require me to move the mounting holes back about a half inch for the TCV. I also rebuilt the TCV with new seals and gaskets. From the photos above you can also see the returns tee'd for the mid lift and the 3 pt cylinders. I'm not sure if I will keep it this way or not. The TCV I'm using has the hole on the side tapped for a return so I could use that as well to keep the returns more separate than just a T on the bottom. I believe this port was used on early power steering tractors for a return but then was moved away from using it. It is also the power beyond port for the 6000 and 7000 tractors if machined for from the factory.

From output side of the TCV lift circuit, the hose runs up to a manual splitter valve. This isn't quite the same as other valves as it is a 3 way I'd call it. It can be just the mid lift all the way to one side. Then the 3 pt all the way to the other side BUT if the valve is right in the middle, it will still work both at the same time which is awesome. Never know when that might come in handy. So the lift lever in the dash will still control both the mid lift and the 3 point depending on the splitter valve. I did cut away some of the one panel to nicely run the hose around it to the rear cylinder. This cutout also gave me more space for the feed and return hoses to the rear pto valve.





The rear hydraulic cylinder was replaced with a john deere cylinder capable of 2000 psi and 4" stroke. JD part #AM147175 AM121141. I used the later as I got a good deal on it from ebay. Both cylinders are the same one just supercedes the other. They are 2.5" bore and 4" stroke. They are a touch longer than the Case cylinder but the rod can be redrilled to bring it damn close to stock length. I will also have to redo the mount as the bottom is completely different than the Case.

The mid lift cylinder is JD part# AM116154. It is also a 2.5" bore and 3.875" stroke and rated for 1000 psi. Now this will not replace a stock mid lift. I completely cut out the stock cross member. I moved it forward on the frame to account for the extra length and made the new cross member out of 1/4" angle. I don't think the stock cross member was even 3/16".... more like 1/8" maybe.

Now the reason both cylinders were replaced is because in my research I've read numerous times about pressure spikes in the system with the splitter and working forces on the return side. So I did what others have done and replaced both cylinders problem taken care of. Now I can also tweak the pressures higher for a bit more grunt as well.

Then the cherry on the sundae is the 3 spool valve on the right side. I knew I wanted more hydraulic circuits on my tractor. I did not want to run multiple splitters so this is how I went. Now this would require you to figure out a different way to tap into the pressure side. With my rear pto valve having a power beyond port, this was easy. I haven't ran any hoses yet but it won't be hard to run a 5/8" pressure hose to it.



The 3 spool valve has three spring to center spools with one of those having a float detent. One spool will go to the front for power angle of the plow. I will probably run some nice hard lines up the side of the frame with quick disconnects on the front like the john deere tractors. The other spool will go to the rear for the hydraulic top link on the 3 pt. This will be awesome especially running a box blade and even a plow for easy quick adjustments on the fly. I can tell you from experience a hydraulic top link and a box blade really works excellent together and makes the box blade much more functional.

The third with the float I think will be for a hydraulic lift arm on the 3 pt. This really isn't necessary, again it is just me playing big tractor on a small budget lol. It will allow tilting of the box blade for say a road crown or drainage on the side of road or garden. It just a little something extra to play with that's all.

The only thing not figured out yet is the return lines from the flow control and the 3 spool valve. I'll have to wait till the motor is mounted to see how the stock return will work or not work. I'm hoping to at least get it out far enough I can weld to hose barbs to it. That way the flow control can loop up over the engine and down to it and the 3 spool will be a straight shot to it.

Now as far as a cooler.... that will all have to wait till the radiator shows up and see how much room I have.

I've been debating on running a aftermarket fluid cooler for say like a racecar. I'm not sure if those will handle the flow of the system or not, I'm thinking not so I'm hoping the oem cooler will work.

I wonder if the 448 or loader coolers work any better than the 446 cooler. I do have a oil temp gauge to run and monitor the system temperature at the reservoir.

Shtf45acp said:

Thank you everyone for the compliments!!!!!

I'll use this post to address all the questions and then later tonight I'll post where I'm at with the hydraulic system.

Dundee- As for no front pto and mid lift... yes I do want to retain original functionality with the mid lift cylinder to do a few things. I want to possibly keep a plow on the front all the time. The case plow is actually pretty heavy duty compared to most other brands. I have the new style designed in fusion 360 but I need to find a place to laser cut and bend the brackets. I also would like to possibly run a middle blade like a road grader with tilt and pivot as well (hint to the 3 spool valve on the drivers side). So keeping a cylinder tucked up on the engine close to the original position will let me do that without have to redo everything. I do not plan on a loader at this point. If I was going to do a loader I think I'd just find a case loader and go that route instead. The Super 446 is going to stay more along the lines of a traditional farm tractor.

Bob- I have seen your post and do have it book marked. Your setup is something I have definitely considered. One thing I forgot to mention was I do want to do a individual rear brake setup. The website and posts by a gentleman named gator I believe is gone but I have started to source parts for it. So that might be a good way to go for the brakes.

Vigo- I will post more of the hydraulic system so far later tonight.

Ddude- I will definitely just be doing the rear hydraulic pto and maybe a front at some point as well. Not sure what I'd use on the front but you never know. That could be done two ways, off the 3 spool valve or just make up some lines off the rear pto valve. I don't think I'd run some front and back at the same time but who knows.

As far as frame reinforcements I do plan on doing something. I haven't seen anything on the rear of the frame, could you post a link? As for the front I have seen numerous failures while researching. My plan of attack is two fold. The diesel block is a very stout structure so what I plan on doing is kind of like a Farmall tractor. The engine will be part of the structure along with the frame rails.

I'm going to make a plate that will drop down in the notch where the Onan sat. It will get welded front to back and will hold the engine like a cradle. Then I'll have two flanges on the each side of the rear to bolt to the starter plate. The starter plate is roughly 1/4" and will work just like a engine mounting plate in say like a racecar.

Then I also would very much like to make a one piece plate that will run from front to rear. It will go over and around the front axle reinforcing that and the front attachment mounts as well.

Then on the bottom of the frame will be a flange, basically making one larger piece of angle iron front to rear. The only place it might cause an issue is around the brake drum. That side might have to be split into two pieces but I think it can be done.

It would be nice to tie into the 3 point plate as well.

Click to expand...

It sounds like you're on the right track for the frame reinforcement. I personally like Bob's video on his loader build series and am doing something similar with mine just different material, I'll add a link at the end of this comment for reference. I am going to use 2"x2"x1/4" angle that will just be welded on to the outside of the C-Channel adding the material to the overall shape. It will take two long pieces of angle for each side and will require a lot of notching to fit around things like the control stack, motor mounts, etc. It's the best way I've figured to do it since you get the edges of the flange to do a full straight weld the whole length of the tractor, and you also get a spot between the two pieces of angle directly in the center of the original C-Channel's webbing to do another full length weld. Also, with my loader build the loader will attach to a semi-removable subframe that will act as extra frame reinforcement. It will attach to the sleeve hitch ears on the transaxle, then connect to the frame in a couple places.

Some helpful links I have gotten:

Feel free to contact me if you need any help brainstorming or some more references to work with.

For the PTO, I plan on using just the one single spool valve I have mounted to control a front and rear PTO. The "front" PTO will be more like a mid/front and will terminate about 6-8 inches before the front axle so I can power a hydraulic mowing deck if my belt drive mid-PTO idea is a failure. The single spool valve will run straight down to a Tee then run from the tee to the front and back of the tractor. Like you, I do not see any use-case where I would need both the front and rear PTO at the same time so I think this will work just fine. Although I personally would not be using mine to run a brush hog of sorts like it seems like you will be, I will likely be just using the tiller and possibly a hydro sweeper on the front. The valve I have can be used for either cylinder or motor operation since I have both styles of detents for it and they're relatively easy to swap out so I will have a hydraulic blade or something of the sort and maybe a dump trailer as well.