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Both a wanted, and an interesting project.


Talbot
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Some people here will have read about and/or heard about the absurd mower I made about 15 years ago.  It was designed to be able to cut acres and acres of grass in a short time.  Something somewhat larger than a lawn-tractor, but not quite as cumbersome as a tractor PTO mowing deck.  It used an XUD engine as a power source, had three hydraulically driven cutting decks and was beyond dangerous.  It would cut a 2M wide swathe of grass at 20mph and fling the cuttings about 20M away from it.  It would also cut down an entire hedge at 10mph if you asked it to.  It was built when scrap was on it's arse, meaning cars were free.  XUD-engined BXs couldn't be given away, even with an MOT.  That meant the mower cost about £20 in materials.  It was referred to as "Mega-Mower"

I'm now looking to make Mega-Mower MkII.  Mega-Mower MkII (hereafter referred to as MMM2) will be designed for the FoD, as it needs something a little more effective and powerful than the 8hp ride-on that currently tries it's best to keep the camping field, orchard and entrance route under control.  I'm not making something to do the main 10-ish-acre field.  MM would have done that.  MMM2 is not intended to do that.  It's meant to be somewhat more manageable and significantly safer than MM.  Mind you, that's not hard.. juggling flaming machetes while dodging traffic on the M25 would have been safer than MM.  The expectation is a machine that can cut grass at a decent speed (faster than walking pace.. maybe 8-10 mph) and have a cut width of about 1.0 to 1.2 meters.  It will also be quieter than a normal lawn-tractor, as I hate having to wear ear-defenders when mowing.  It will also have a towbar and be a useful shunting engine up at the FoD.  If it can cut the entire orchard, the camping field and the access route in an hour, that seems ideal.

Anyway.  What I need is the donor vehicle for this.  As I do not need 70hp of an XUD9A or even 62 hp of an XUD7, I'm looking towards the TUD engine as a basis for this mower, possibly the early Ford 1.6/1.8D engine, or similar offerings from other stables.  I do definitely want to stick with a mechanical injection engine as that will be massively easier to set up for mowing (speed regulated rather than power regulated), and it needs to be pretty much the smallest diesel engine available.  Another XUD engine'd one is overkill.  Petrol is definitely out, as it would be good to have this running on Red Diesel or similar (heating oil cut with used engine oil maybe.. something like that)

So I'm looking for a TUD, and most of the front of said TUD-engined car.  I would rather it not be a complete and roadworthy car, as that's a bit of a waste.  Ideally I need something that's either completely and utterly rotten, or has been crashed/rolled/otherwise fucked (maybe both?), but the engine still runs and the front isn't banana shaped.  So I'm looking for:

  • Citroen AX Diesel
  • Citroen Saxo Diesel
  • Pug 106 Diesel
  • Rover Metro Diesel
  • Ford Escort/Orion Diesel from the late '80s/'90s
  • Vauxhall Astra/Cavalier Diesel from the late '80s/'90s
  • Anything else with a small mechanical diesel engine.

I guess I could look at XUD stuff again, as that does open up the range of available vehicles somewhat.  I could go as modern as something with a DW8 in it, as it's very easy to shove a fully-mechanical pump on them and make them ECU-free.  If going down that route, my preference would be for a BX Diesel or an early Xantia Diesel, as on MM I used the Citroen hydraulics as the cut-height control, and it worked beautifully.  MMM2 could just have mechanical height-adjustable cutters, but where's the fun in that?  If I do go XUD, that does make it somewhat more familiar to me.

I will likely also need a second front subframe and suspension/brakes/struts etc. from the same car.  That could possibly be scrapyard sourced, but the more popular the car is, the easier it will be to get.  MM used all BX components as I was given about 3 BXs back then, so parts were plentiful.  I know it's just not like that any more.

I will also need the differential from a couple of RWD Mercedes, along with about a foot of the prop and at least half (or hopefully all) the rear driveshafts.  Candidates for that are 190s or C-class.  E-class diffs are getting a bit big.  I think I can lay my hands on exactly what's needed from a W202 C180, so might only need one more.  Knowing the Merc specialist I do, this might be the easier of the parts to source.  The diffs do need to be the same (or at least similar) ratios.

The other parts that will be needed are PAS pumps.  Definitely four, maybe more. These are used as pumps on the engine and then with the pressure regulator removed as the hydraulic motor for the cutter blade.  Very effective, and it means you can hydraulically engage/disengage the cutters.  Far more elegant than slipping belts.  Likely to need two larger ones for the pumps, with then smaller ones on the cutter blades in order to get some up-gearing and make the cutter blade spin fast enough.  Citroen HP pumps were ideal for the "motor" ones, as they tend to be small-volume-high-pressure pumps, which means the output from a higher-volume pump gives an excellent "gear ratio".

There is no hurry for this.  I'd rather wait and find a rotten Pug 106 / Citroen Saxo that has had a nasty rear-end shunt for cheap than attempt to use something I'm not familiar with, but we'll see what turns up.

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Quite the opposite.  I need a diesel engine that can sit at 20-30hp output, at 1500rpm, for an hour at a time, which maintains it's speed in relation to load..  The ideal engine would be a Perkins speed-regulated diesel engine.  Something like would be fitted to a dumper truck or a digger.  Or a Kubota or similar.  A revvy petrol engine is the worst possible engine for this project.

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This reminds me of a mad project of an employer. With lots of grass to have cut and no commercial suitable mower available (so they said) they had a local firm cobble together a mower from a pair of SaaB 900 front ends welded back to back at the A-pillars, hydraulic motors driving each wheel via the driveshafts and an Escort Diesel engine driving a JCB hydraulic pump. It was dangerous and useless. The driver sat really high , alongside the engine. The combination of high centre of gravity and the suspension travel made the rotary cutting deck useless as the thing rolled and pitched on it’s springs. Eventually the gardener just refused to use it and it was quietly hidden in a shipping container…

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5 minutes ago, Asimo said:

This reminds me of a mad project of an employer. With lots of grass to have cut and no commercial suitable mower available (so they said) they had a local firm cobble together a mower from a pair of SaaB 900 front ends welded back to back at the A-pillars, hydraulic motors driving each wheel via the driveshafts and an Escort Diesel engine driving a JCB hydraulic pump. It was dangerous and useless. The driver sat really high , alongside the engine. The combination of high centre of gravity and the suspension travel made the rotary cutting deck useless as the thing rolled and pitched on it’s springs. Eventually the gardener just refused to use it and it was quietly hidden in a shipping container…

MM was quite the opposite.  It had no actual suspension, so the cut was quite well controlled.  You don't need suspension on a mower/lawn tractor.  It was dangerous, (ok, scratch that, it was lethal) but it was super-effective.  I could cut about 5 acres in 40 minutes or so.  It was probably 10 times faster than the 13hp lawn tractor it replaced.

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58 minutes ago, Talbot said:

Quite the opposite.  I need a diesel engine that can sit at 20-30hp output, at 1500rpm, for an hour at a time, which maintains it's speed in relation to load..  The ideal engine would be a Perkins speed-regulated diesel engine.  Something like would be fitted to a dumper truck or a digger.  Or a Kubota or similar.  A revvy petrol engine is the worst possible engine for this project.

Fairy muff.

I'm breaking my MG ZR in August - sans interior, engine, wiring loom, ECU etc. Another chap wants the fuel tank, so if there's anything that either of us don't need then you're more than welcome to it before it goes in el crusher.

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As an interim "fix", would there be any way of cobbling a silencer onto the FOD mower and raising the gearing a bit?  You probably wouldn't be able to use it flat out in the orchard but the paddock is a bit smoother and should be mowable at a reasonable speed.

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1 hour ago, sierraman said:

I’ve got a PAS pump you can have from a Zetec for postage?

The Pumps and Motors are pretty much the last things needed, but I'll bear you in mind.  I don't know ford pumps very well, so have no idea of their capacity (ml/rev) or whether they have pressure regulation built in or not.

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50 minutes ago, wuvvum said:

As an interim "fix", would there be any way of cobbling a silencer onto the FOD mower and raising the gearing a bit?  You probably wouldn't be able to use it flat out in the orchard but the paddock is a bit smoother and should be mowable at a reasonable speed.

The noise might be able to be brought down a bit, but the issue with the existing mower is that it's underpowered.  If you put it in top gear, it moves quickly enough, but simply cannot cut grass at that speed.. it just bogs down and fails to cut properly.  It's remarkable how much power is needed to cut grass, and 8hp (or at least it used to be 8hp once, a long time ago) simply isn't enough for that mower, hence you have to reduce the rate at which you feed grass to it for it to cope.

If there was maybe 20hp available to that blade, you could then introduce grass to it at a faster rate and it would cope, which is exactly what I'm proposing.  You also have to look at the blade rotation speed versus the vehicle travel speed to see what the cut advance is with each blade revolution.  Very much like milling machine feeds and speeds calculations.  There's more science&maths to cutting grass than people often think!  Similarly to a milling machine, the 70hp XUD powered MM (when absolutely flat out) used about 65hp to cut grass and 5hp to move.  Even that could be overloaded, so if you went at heavy undegrowth too hard, it would bog down and stall.

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This sounds like a super interesting project. It's got me thinking about a hydraulic can compactor I've always wanted to make- two hydraulic rams to precompress and then cully compress bales being powered by an old diesel. I might have to do this one day.

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45 minutes ago, Talbot said:

The Pumps and Motors are pretty much the last things needed, but I'll bear you in mind.  I don't know ford pumps very well, so have no idea of their capacity (ml/rev) or whether they have pressure regulation built in or not.

Haven’t a clue but there’s no rush whatsoever.

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No pictures of it unfortunately.  It was built while I only had the shittest 640x480 digital camera in existence which regularly completely corrupted it's 8MB CF card and lost a week's worth of images.  I also wasn't very good at making sure I had pictures of everything.  It was left where I used to live in Dorset with *explicit* instructions on it's use by my ex-landlord.  I desperately hope it's completely broken and/or scrapped by now, as it was truly lethal.  If it was running at full wallop, I have no doubt it would have cut any limb clean off, and continued on it's way without even slowing down.  I once removed a length of hawthorn hedge that needed to come out by simply running one cutter at full wallop and driving forward at minimum speed with the cut height at maximum.  5 mins later, 50' of hedge was gone.

The biggest issue is that the 700mm cut blades had no guards at all... the PAS pumps being used as motors were just bolted to the end of a length of box-section steel.  If you stood the cutter up on end (vertically) it looked like a 2-blade windmill.  Meant there was no cutting deck to clog up.  But meant there was no cutting deck to separate the spinning blades of death from anything alive.

It did (and I intend MMM2 to also have) Power-assisted 4-wheel steering.  The major benefit of that was you could run your 2M wide cut up a field and then do a 180 turn and cut back along the side of the cut you've just made.  No need to do racetrack loops.  That was for doing a 5 acre field as quickly as possible.  MMM2, however, will need to be smaller and be able to get into and out of the orchard at the FoD without cutting all the trees off at ground level.  Something that MM would have quite happily achieved, whether wanted or not.

You can no-doubt see why I'm thinking another XUD-powered one is excessive.

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33 minutes ago, Minimad5 said:

Surely a safer bet would be to buy a ride on mower, but give it a bit more 'pep' 

I'm all for this sort of madness, but blimey mate be careful- Folk could literally be maimed / killed / de-skinned 😅

MM was dangerous.  I plan for MMM2 to be as safe as any other ride-on mower, just larger and faster.  It will have guards, cutting decks, operator cut-outs and various other safety systems to ensure that no-one is even slightly maimed.

To buy a ride-on mower that is as effective/quick/useful as this, you'd be looking at many thousands of pounds.  Maybe tens of thousands.  Even used machines of that sort of size make really very good money.

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  • 2 weeks later...
On 7/29/2021 at 10:42 PM, Talbot said:

To buy a ride-on mower that is as effective/quick/useful as this, you'd be looking at many thousands of pounds. 

Agreed. I'm looking to buy one at the moment (actually I've been half looking for years). Low volume production does not make for a cheap product!

https://www.ggmgroundscare.com/baroness-gm2810-5-deck-rotary-mower.html

(I'm after something considerably smaller and cheaper BTW, the problem is finding one which can cope with rough/soft terrain, and the occasional rock without damaging itself. One with giant strimmer heads would be ideal!)

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7 hours ago, mat_the_cat said:

(I'm after something considerably smaller and cheaper BTW, the problem is finding one which can cope with rough/soft terrain, and the occasional rock without damaging itself. One with giant strimmer heads would be ideal!)

You need MMM3!  Coming in a very long time to somewhere nowhere near you!

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  • 2 weeks later...
On 7/29/2021 at 11:43 AM, Talbot said:

So I'm looking for a TUD...   ...Ideally I need something that's either completely and utterly rotten...

Well.  That didn't take long:

One rather rotten Saxo 1.5 Diesel.  A-Frame being assembled onto it:

20210819_130715.thumb.jpg.da292d2b2e003c06b177e9dcd4a5981a.jpg

And ready to go.  Bonnet and wings were loosely re-assembled as it just looks more "right":

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En Route, obligatory Pez station shot:

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Abandoned at the FoD:

IMG_0228.thumb.JPG.b5c335e75f6bcfae4767ddcc17d1a2fc.JPG

Many thanks to @jcr for this.  I think there was an all-round sigh of relief from various people when this was framed away.

So.  That's a TUD engine, an associated gearbox, and one axle, plus some brakes, steering gear etc.  I will be keeping my eyes open for another scrap saxo/106 now, as I need another front subframe/hubs/brakes/etc. as the mower will be 4-wheel steer.  Oddly, this has electric PAS, which I've not worked with before.  Could be interesting.
Time to get cutting this up.  There's no need for the entire car to remain!

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