10 replies to this topic

[dave21478]

I bouht this digger a while back and the injection pump has died. The local place wants 3k to rebuild it, and second hand, they are rarer than teenage virgins on a council estate, and the chap in UK wh might rebuild it cheaply hasnt got back to me yet, so a complete engine swap is on the cards as I need it up and running asap to earn some dollar.

Its a Neuson 5001 RD, approximately 1988 vintage...


It has a Yanmar 3 cylinder, turbocharged unit, which gives 60bhp...

In the bottom left of this pic, you can just see a red lump - this is the hydraulic pump. Digger engines have no gearbox etc, the pump is driven directly from the engine flywheel, and all movements of the digger, arm, tracks etc are run by hydraulic motors or pistons.

So, with an engine swap looking likely, I picked this up from a chap I know...

an early vauxhall nova TD, (called an Opel Corsa here!) which his son rolled. Its been sat for a while, but seemingly the engine is sound, and before the prang, had new turbo, new belts and a good service.


There was nothing delicate about the removal - lifted the front up with the tractor, used the big grinder to cut through driveshafts, exhaust, tie rods etc, then dumped the engine out the bottom, lifting the empty shell over the top.


I then took off the hydraulic pump from the yanmar unit, to see how it was connected. Surprisingly, its driven by this cross-shaped pinion... (drive disc removed from flywheel in this pic)

which slots into a plastic disc that was bolted to he flywheel, which you can see to the left here....

I assume this is a safety feature - if the pump were to lock up or seize for some reason, this disc would break, preventing damage to the engine. I'm quite happy though, as it should be easy-ish to adapt to the corsa engine, and the nature of the coupling will take up any imperfections in my machining.

off with the corsa clutch assembly...


A good bit of 4mm plate was rummaged out of the scrap pile to make an adaptor plate. Here, I am tracing the mounting holes from the clutch, so it will bolt to the flywheel....

Lacking a lathe, all work was measured very carefully indeed and the cutting and grinding was done very slowly on the bench grinder. Holes were drilled with the neighbours pillar drill.

and voila - the adaptor plate bolts to the corsa flywheel using the clutch mounting holes, and the plastic drive disc bolts to the adaptor...


Turning the engine over, There is no measureable run-out so its well centred. and all the holes are equally spaced around the circumference, so balance shouldnt be a problem either.

[dave21478]

I then started on the engine mounts. The plan is to mount the engine and hydraulic pump on 2 chunky steel rails, and lower the whole lot into the engine bay and mount it on the existing rubber mount.






I deliberately left this last plate much bigger than needed, as I will need to fabricate an alternator mount there too. I'm missing the Corsa one, so will mount the Yanmar alt in its place with a custom bracket.

[dave21478]

The other sides rail...




I then decided I was not happy with the pump coupling though. Its unlikely that I will get the pump mounted EXACTLY in line, so there will likely be a couple mm of play somewhere. Looking at the plastic disc - at best it will wear very quickly, at worst it will shatter, and I don't want that happening at 4k rpm.
I spent today looking around for some kind of rubber coupling to act as a driveshaft but that can take a few mm of play and damp out vibrations. A rotoflex kind of thing will probably do the job.

[Jordie]

wow, top effort.

Something different and i enjoyed looking at the pics and your home modification to the flywheel etc.

Look forward to the rest of the topic

[ckendall]

Top job nice to see some home engineering at work

[Bungle]

Little bungle wants one

[daemonchild]

Cooooooooool!

[mighty mini jack]

Saw this on RR, you crazy man. I love it!

[alexcrosse]

poor nova

[dave21478]

I have binned the plastic drive disc - it was just too likely to all go horribly wrong. Although there was a slight margin for error with it, if my machining turns out to be too innacurate, it would be likely to shatter the disc.

So, I removed the cross-shaped pinion from the pump, and made this to go in its place....


I then re-modelled the flywheel adaptor plate slightly, and drilled 3 holes in it centrally. This allows me to bolt on this rotoflex style drive coupling....


The smaller disc bolts into the 3 spare holes you can see, so the rubber coupling will act as a driveshaft, damp out vibations and be flexible enough to absorb any imperfections and misalignment.


Happy enough with that, I cracked on with the pump mounting, which I made from an old bit of steel channel, cut a big hole in the middle for the pump neck, 2 smaller holes for the pump to bolt to, and reinforced it with some angle iron and bits of flat steel.




I will drill holes in it so it will bolt into place, rather than welding, so it can be dismantled more easilly, and I can adjust the alignment slightly if needed by elongating the holes.

[dave21478]

Thanks for the comments,

Today I hoiked out the Yanmar lump and dropped the Corsa engine in. It fits very well and is actually a more compact unit then the Yanmar.

Its just sitting on bits of wood just now, but tomorrow I reckon I will get the mounting plates made that will bolt to the big rails and sit on the standard rubber mounts on the digger chassis.

Once thats done, I just need to build an exhaust system, sort out the plumbing, fit an electric rad fan, then do the wiring.

Does anyone know what the two wires from the top right in this pic are for?
They come out of the injection pump and end in that 2-pin plug. Its not the stop solenoid, thats the wire dangling down from the centre of the pic.