My new 644 arrived

[Eugen]

I guess you're making sense. But if I were anywhere near you I would personally help you get that diesel engine in there. It's just such a nice end result.

And I don't think Kubota made any water-cooled diesels less then about 16 or 20 hp. One of the little Hatz style air-cooled diesels could be 10hp or under, but I think anything water-cooled is going to be plenty of power.

But again, I recognize you're doing the responsible thing.

just not the FUN thing.

I appreciate it Bob. I can do fun after, when things aren't so hectic. It is water cooled and it is 10 hp. The z400 engine was used in the Kubota G3200 mower. Must not have been very popular, not that many around of this engine.

Back to reality though. Today I did some scouting in Princess Auto (similar to your Harbour Freight but probably fewer options and stuff). I have this more modern and new, never used 420cc engine claiming 19 ft lbs of torque and 16 hp. It came with a parts OHV 446 at some point.

It also came with a new hydraulic pump and proper mounting. The pump has 0.732 displacement and 12.7 GPM.

A little more than the original, but I suppose that should be fine. Has ORBF 12 inlet and 10 outlet. The result of my scouting was some fittings: a 3/4 ORBM to NPTM straight adapter, and then an NPTF-NPTM 90 degree elbow. Will try to connect a 3/4 hose on this to go to the tank.

For the outlet I got an 1/2 ORBM - 1/2 JICM.

I'm thinking to replace the current steel line that goes to feed the TCV with a flexible hose of appropriate size, to give me flexibility in mounting the engine to the frame. Might not have yet the right fittings or hose.

Oh yeah, and I had to replace the L095 flex coupling that came with the pump and motor, seemed to me it was too small. Got the L099. Bore size 3/4 on the pump side, and 1" on the engine side.

[Eugen]

Came across this today. The continental f140 engine 2.0L four cylinders. Local out of a combine. Look at the great shape it looks like. So a small diesel engine would be cool in the 644, but how cool would this Continental be in a 444 for garden duty?! I won't get it but I wish I could.

[DavidBarkey]

Came across this today. The continental f140 engine 2.0L four cylinders. Local out of a combine. Look at the great shape it looks like. So a small diesel engine would be cool in the 644, but how cool would this Continental be in a 444 for garden duty?! I won't get it but I wish I could.


80CE13E3-2D90-4D45-8B85-29F4FAA83B01.jpeg

That would be like having 4 K301 nose to tail in compacted form .

[Eugen]

Obviously I didn't think it through. Transmission and all that. The MH20 used this engine. Nice little tractor!

[Spike188]

You wou think the onans were fuel missers compared to the continental. I feed a few of them.

[Eugen]

You wou think the onans were fuel missers compared to the continental. I feed a few of them.

Indeed, this would guzzle gas like crazy


Anyway, back to the 644. I'm pondering now what would be the best way to connect to new pump to the system. This is what the original looked like, but what I want is to have flexible hydraulic hoses so that the engine could be moved around for best fit on the frame, and not be constrained by the rigid steel hydraulic connections.

What I'm slightly unsure about, are two things.

1. The pump inlet feed connection. The original pump has the steel pipe with the little bump on its end so that the 3/4 hose can be clamped securely to it. The new pump only has the ORBF size 12 port, and without thinking too much about it, got the ORBFM to NPTM straight adapter, then an NPTF-NPTM 90 degree elbow. Might just be ok clamping a 3/4 hose on it, but would be happier if there was something better to clamp on here. Can go with this hose all the way to the hydraulic oil tank, I think there would be enough clearance on the side there. Once I put the engine on the frame for mock up I can see that better.

2. The original pump outlet went directly into that steel pipe which goes to the TCV. As I said, I want this pipe replaced with a flexible hose. The little fly in the soup here is that the original steel pipe has a few bends so that it clears nicely the various items in that small place, including the steering cog. A hose in straight line from TCV to pump would not be nice. A compromise would be to pay attention to parts in that area that are moving, and/or are hot (exhaust?) and tie the hose to keep it away from those. Ideally I had a shorter steel pipe connected to some length of hose to have enough flexibility for engine repositioning.

[thebuildist]

I'll admit, it is a pain to bend and flare 5/8" (JIC10) steel hydraulic tubing. But i've successfully done it, and it can be a better end result than hose. It can be tightly routed, it's not heat sensitive, and unlike hose, it never "just gets old".


For a bender I use something like this: https://www.aliexpress.com/item/2255800643015789.html Mine was from ebay, about 95 including shipping.

It doesn't bend as tight of radius as some of the factory parts, but it's still possible to make most needed shapes.


And I mentioned earlier that I use an inexpensive eccentric flaring tool.
https://www.ebay.com/itm/Eccentric-Flar ... 3405799442
Mine came with a 45degree flaring cone. That cone is difficult if not impossible to remove, so I held a grinder flap disk up against it, grinding away the cone as it freely spun. I stopped when I felt like I had removed about 8degrees of cone, so now it's a 37degree flaring tool.

Unless this tube needs some very close/tight bends, that's the route I'd go. You might consider it.


Bob

[Eugen]

Bob, it's a great suggestion, but around here I wouldn't even know where to get hydraulic tubing from. Do you know a source @DavidBarkey ?

So, how will I build that little backhoe?

[Gordy]

Bob, it's a great suggestion, but around here I wouldn't even know where to get hydraulic tubing from. Do you know a source @DavidBarkey ?

So, how will I build that little backhoe?

Here are backhoe plans for sale, or use something of known size like a front tire for scale and draw up your own plans from the pictures

https://www.loaderplans.com/


Gordy

[DavidBarkey]

You wou think the onans were fuel missers compared to the continental. I feed a few of them.

Indeed, this would guzzle gas like crazy


Anyway, back to the 644. I'm pondering now what would be the best way to connect to new pump to the system. This is what the original looked like, but what I want is to have flexible hydraulic hoses so that the engine could be moved around for best fit on the frame, and not be constrained by the rigid steel hydraulic connections.

What I'm slightly unsure about, are two things.

1. The pump inlet feed connection. The original pump has the steel pipe with the little bump on its end so that the 3/4 hose can be clamped securely to it. The new pump only has the ORBF size 12 port, and without thinking too much about it, got the ORBFM to NPTM straight adapter, then an NPTF-NPTM 90 degree elbow. Might just be ok clamping a 3/4 hose on it, but would be happier if there was something better to clamp on here. Can go with this hose all the way to the hydraulic oil tank, I think there would be enough clearance on the side there. Once I put the engine on the frame for mock up I can see that better.

2. The original pump outlet went directly into that steel pipe which goes to the TCV. As I said, I want this pipe replaced with a flexible hose. The little fly in the soup here is that the original steel pipe has a few bends so that it clears nicely the various items in that small place, including the steering cog. A hose in straight line from TCV to pump would not be nice. A compromise would be to pay attention to parts in that area that are moving, and/or are hot (exhaust?) and tie the hose to keep it away from those. Ideally I had a shorter steel pipe connected to some length of hose to have enough flexibility for engine repositioning.


644hoses.png

I have never worked on 600 series . But all the 200 and 400 tractors I have had , all have flexible hose from the pump to the TCV. Check you other tractor. I would go that route if you are putting anything in there for a pump and or engine that is not stock as you may not get proper alignment . There is a place in the south end Barrie I get custom hoses made while I wait . Chuck Cooper at Omniflex They can make almost any thing .