The BritishV8 Pub

Belting the PTO to the shaft is a common arrangement for belly mowers and works well. Done right it can leave the PTO clear for other uses too. I don't think the 8N ever had aux hydraulics but it does have hydraulic lift arms so there is a system pump. That means there is a way to tap into that system, and someone somewhere has done it. As I understand it, there is a piston pump in the bottom of the housing (sump) driven by the PTO shaft. The control valves are integral, and there is a pressure tube up to the 1 way cylinder. It should be possible to plumb a diverter valve into that line and use that to run aux hydraulics. When using this scheme it is usually necessary to switch the diverter valve when the arms are at something less than full lift, closing off the cylinder, then pull the control to full lift activating the pump and pressurizing the aux hydraulics which, using open center spool valves will allow flow back to the sump. I use this method on my Yanmar end loader and it works very well as long as the arms do not have to be at full lift.

Jim

It was my understanding the guys adding front loaders and such were all using an external pump such as these. I have never seen anyone tap into the hrdraulics in the 8N which would be an intersting idea. Mine is on the bench right now as it will be re-built in this process:

[www.splitez.com]
[www.ssbtractor.com]
[www.tractorshed.com]

The 8N belly mowers I have seen are actually belt driven in a complex pully arangement from the rear. I was just thinking I would like a PTO driven arangement better:

[www.oldfordtractors.com]
[www.wengers.com]

You are correct on both counts Gary, however that's not the only way to do things, and being able to avoid tying up the PTO is a real advantage, to say nothing of an external tank, filter, and lines that have to be in harm's way. If I had the tractor torn down I would darned sure install a diverter valve in that line even if I wasn't planning on using it. Put a quick disconnect on the end and it's always available if needed. It may not be as fast or powerful as a PTO driven external pump (or it might) but it is self contained. Personally, I would plumb the diverter into a tractor mounted 4 way valve, open spool, spring detent to center one way, locking detent the other, pressure relief optional, (the system almost certainly already has one) and have two quick disconnects for a 2 way cylinder. Then if you wanted to run something like an end loader just detent lock the valve and plumb that QD as the pressure side and the other as the return. There is no end to what you can do with the hydraulics but this would be a great start.

The shaft driven belly mowers aren't cheap generally, but they use shorter belts which cost way less than the long ones needed for the belt only drives. The one on my M/F (Iseki) is driven from a forward pointing PTO but it still has two belts on the deck. I can usually buy replacements for $25 or less, where a long belt to the rear would tend to cost around a hundred, maybe more depending on what it is, and probably wouldn't last as long. Then the idlers at the rear are a constant source of trouble.

There are shaft driven decks which use a short belt to the rear PTO. I think these are a good choice. The rear belt can sometimes be a poly-V or a cog belt which will transmit more power and last longer. The poly-V is probably the most common in newer equipment, single or double V on vintage.

There are two ways to retain use of the PTO with the belt pulley. One is a pully that mounts on the PTO and has a PTO shaft out the back. It shortens the PTO shaft needed for your other implements which can be a real pain, especially if you already use an over-run device to keep the deck from powering the tractor forward (a very smart idea) which also shortens the drive shaft. The other is a thin cast iron pulley that slides far enough up the shaft to leave the stub available and clamps on. That type is better if you can find it. Of course most of the over-run clutches I've seen have a good bit of play in them and aren't real great at handling side loads so finding a good one might not be easy, but if you run across one with a pulley built in you're golden.

Jim

One other thing. If I was retrofitting hydraulics I would shoot for an engine driven pump. Nothing like having to shift into neutral and let the clutch out just to raise the implement.

Jim

I will have to think about all that Jim. I will have to take a good look at the routing to see if it is something I would want to spend time on or would be feasible for me.

I am not sure an engine driven pump is an easy option just because there is little room up front. I was looking at that in thinking about power steering. I am actually changing the steering geometry where there is far less need for power steering.

G

I got a mess of parts powdercoated using my kiln. I need to get the rest of the red parts too large for me to do ready. Still stripping and dissasembling. Got most of the body work sand blasted. Doing a little finish work and it i going off to the painters.

Having fun now,

Got the engine back and I have just a few things to finish powder coating. Got a table full of new parts. The only thing red that will be painted instead of powdercoated will be the engine block and head. Everything else red is powder coated.

Everything grey, fenders, hood, lights etc is at the painters.

These parts I podercoated in the kiln:




These parts I had comercially powder coated:





Edited 1 time(s). Last edit at 04/04/2012 03:18PM by burner1.

Like.

Gary, I had to redesign my end loader for the Yanmar (F17D) and in the process I moved the auxiliary triple spool valve assembly from the loader over to the tractor fender. By doing that I found a way to plumb the tractor hydraulics through the spool valve between the pressure relief and the lift arm controls. In this case it was just a matter of tapping into two ports and making up a rod with o-rings to block off the connecting passage, but even if you had to drill and tap the ports it'd make sense to do it. It works very well, no need for a diverter valve and all of the controls are active at any time. Plus I now have the lift and dump controls for the loader plus one other circuit for the 3-pt hitch top link or a Bobcat attachment for the loader such as a drill or jackhamer, should I have occasion to need one. I don't see any point at all in adding an external hydraulic system when the internal one is more than adequate and spends most of the time idly circulating fluid. Oh, I did just think of one. You said your pump is driven by the PTO shaft I believe? So the clutch has to be engaged for it to work. That could be a bother.

You are probably a little concerned with originality, but aux hydraulics were ALWAYS a high value option with those tractors, and eventually the manufacturers caught on to it. Even a tractor as early as yours is very likely to have ports that can be configured for them. The hardest part has been bending the hard lines that run to the spool valve and from it to the disconnects. I used some 1/2" line I had left over from building the end loader for the supply and return lines, and 3/8" galvanized brake tubing (standard 19,000 psi burst pressure) for the cylinder lines. The larger supply lines will help keep the fluid cool and the smaller cylinder lines are large enough yet compact enough to be easier to route. I'll try to post a photo tomorrow after I have the last line on the tractor.

Jim

I'd like to see it Jim. I did post the question on a tractor forum and the response was (not necessarily correct) that the pump is does not have enough flow. I don't believe that completely because it moves a 2.5" di piston to move the arms internally.

I have rebuilt the pump and I know exactly where to tap in. I had written it off as not worth it but your making me think again.

Oh I'd definitely consider it. My tractor also has about a 2-1/2" internal cylinder and the arms operate at typical speed I'd say. I have twin 2" lift cylinders on the loader and it works very well. I have worked that loader extremely hard in the past and the hydraulics have done an excellent job, has more force than the tractor is big enough to make use of, and very good speed. I did have twin 2-1/2" bucket cylinders (about twice the volume of 2") and they were just a little slow but still acceptable. I've gone to a single bucket cylinder on the new design.

I'll get you that photo tomorrow evening.

Jim

Here is an update. I am getting the tractor back together. As I looked at the hydraulics it was easier then I expected. There is a plug in the corner which means I don't have to do anything now.

Anyway, it's all coming together pretty quickly now. I'll be mowing again soon:

That really is looking good Gary. Love your attention to datail in everything you build.

Thanks Bill, when I started re-doing te engine it wasn't much more work to do everything. In the end the tractor will be darn near new at a fraction of the cost of a new tractor.