Diesel L200 attempt

[mitbes]

Calling this “attempt” as still not 100% sure its going to work.

Goals:
Planning on putting a Kubota diesel engine into a L200, because I have always wanted a Kubota powered car. That’s pretty much the whole reason. The engine needs to have a similar power output to the EJ, so aiming for 40kW.

Engine Selection:
There are many different types of kubota diesel, however due to the crank length restrictions in the L200 engine bay the only options were the 3 cylinder 70mm stroke series and the later version, the 02 super mini series. The 70mm stroke comes in 750, 850 and 950cc and is fitted with a pfr3kd injector pump, which is capable of housing 7.5mm elements for a huuuuuge fuelling potential with a max delivery of 100cc/1000strokes. This is enough fuel for probably 120kW although the engine would explode.

The super mini series is much more modern and also comes in the 720 - 920cc configurations. It has a MLS head gasket, which is nice, but has a pfr3md pump which only goes up to a 5.5mm element. This pump is capable of flowing 40cc/1000strokes

So either engine would probably be ok, they are both around 14kW stock, yes that is correct 14. However they are super lazy industrial motors that are usually rated at continuous output. So now I just need to work out how much air will I need to jam into this poor thing.

Turbo Selection:
To get these engines to survive what I am going to do to it, it needs to stay cool. This means lean burn in a diesel, to keep EGT controlled. Excess air is easy to add as long as the turbo spools and can flow enough with the exhaust energy provided. So I did some maths and the required air for 40kW with a 20:1 AFR is about 7.45lbs/min (going to lbs here because Garret maps are in lbs) In a 750cc engine this means a total PR of ~2.75.

Garrett GT1241 map:

This turbo has the flow requirements, but really 2.75PR is off the map. Also this thing just isn’t going to spool at low RPM.

Garrett GT0632sz map:

This turbo isn’t quite big enough, and also 2.75PR is off the map. At high RPM it’s going to choke.

So the solution? Compounds, with the GT12 as the LP turbo and GT06 as the HP.

[mitbes]

The GT0632sz is the smallest turbo made by anyone I think. It’s for the Tata Ace, which has a 2 cylinder 800cc common rail diesel that has 30kW and 80Nm, which is pretty much what I am aiming for - so sizing should be very good.

Compounds mean each turbo runs a PR ~1.7, which is right in their happy place. Flow through the GT06 is at the elevated PR, which means it hopefully won’t choke. Note I am doing the compounds not for extreme performance, it’s to get boost early and maintain it up high. Compounds gives me a really broad boost capability and plenty of excess air to keep the EGTs down.

Some more math, 40kW@4000rpm with corrected airflow for the HP stage:

• GT06 is 4.95lbs/min at 1.65PR - good
• GT12 is 7.45lbs/min at 1.65PR - good
• Engine requires 33cc/1000strokes of diesel - good, either pump can do it
• Engine is at a BMEP of 1.56 - good, not too stressed. Similar to most OEM automotive turbo diesels.

So it looks like it’s possible. I kept an eye on marketplace and ended up with a D750. I would have preferred the D950, as it’s the same block, however the engine was $300. When I find a cheap D950 everything will bolt across. The 750 and 950 are the same stroke and same block, just different bore. So the 750 has much more meat around the head gasket, maybe that will be an advantage.

Here it is next to an EJ:

They are the same length from gearbox mounting face to front of engine pulley. Pretty much same width and little bit shorter as they are pushrod so less height from the cylinder head.

EJ weighs in at 63kg as pictured, D750 weighs in at 54kg.

Gearbox, Clutch & Adaptor:
Through some research and general good luck I ended up with a $50 L251 gearbox with a 327 tag. This gearbox has a 3.9 final drive and 0.7 5th gear ratio. This means on 175/50R13 tyres I will be spinning 3000rpm @ 100km/h, so all good there. Interestingly there isn’t really a taller FWD gearbox I could find, the L251 charades for some reason have nice tall gearing, maybe to suit the small tyres.

Clutch is a Exedy DHD047U from a k3 Terios, 190mm friction disk. I am machining the Kubota flywheel to suit this clutch/pressure plate. This friction disk gives me the offset spline I needed for everything to line up. Here it is next to an Applause clutch, without the offset spline:

Adaptor is a 6mm aluminium plate, just profile cut. Lucky the offsets and positions all work well so I don’t have to do anything crazy here. This is the 3rd custom gearbox adaptor I have designed, and by far the easiest.

[mitbes]

Cooling:
The D750 doesn’t have a water pump. It only cools in standard configuration using a thermosiphon so I will be adding a Davies Craig EWP115 with pump and fan controller. Using the standard EFEL L200 radiator.

Intercooler will be a water to air, between the HP turbo and intake manifold. Not going extreme on the LP boost so an interstage cooler isn’t really worthwhile - plus there’s just no room.

The Car:
92 4 door L200. Currently has a EJ in it and the EF gearbox.

• 4x100 Sirion brakes f+r
• 13x6.5+35 with 175/50r13 NS2Rs
• Matiz front struts
• Excel rear shocks
• 45mm lowering springs from Japan
• Dirty rattle can 2 tone

Next step is to get the gearbox adaptor machined, flywheel machined and the turbo manifolds 3d printed out of SS 316. Never done it before, but pricing from China is incredible and hopefully it means I can take it out of the box and bolt it straight on the engine. Will see if true.

[evilhighway]

So glad you did do this. Makes me really happy to see this. I am too buggered to read atm but will as soon as I get a chance in a few days?

[b_hoves]

So keen to see how this works out!

[mitbes]

First manifold printed, in plastic to start with. Going to mount the turbos something like this.

Also some more parts arrived, EWP115 with pump/fan controller and another water pump for the water to air intercooler. Hoping to use a water to air intercooler from a LDV, should have it soon to measure up. The Davies craig gear is hepful as there is no mechanical waterpump and no thermostat on this engine. In the tractor it’s from it just runs a thermosiphon - so that sort of shows how low stressed it is normally.

I am going to be instrumenting the engine more than most people would, as I don’t really want to kill it too quickly. Will be running individual cylinder EGT, so I can make sure the fuelling is even across all three cylinders. This is adjustable on mechanical injector pumps, and is usually bench calibrated however with the significant extra air I will be pumping I want to make certain there isn’t something silly going on. Just using some very cheap aliexpress k-type thermocouple gauges and have some 50mm long k-type probes that I will incorporate into the exhaust manifold to point as deep down the exhaust port as I reasonably can. Boost will be measured at LP turbo, HP turbo and Exhuast manifold pressure, also with a cheap aliexpress gauge.

[evilhighway]

not sure if you know but you can get diesel wideband afr kits these days. I was going to get one for my pregio when I had it. They are a little more expensive than the normal kits but they do cover the fuel to air range. Just another option I guess.

[mitbes]

Yes they are great for common rail tuning where you can actually increase fuelling as boost increases, and either aim for a smoke limit or maximum power. On the mech pump all I can adjust is full load fuel rate, and that will be to a target egt rather than afr. At low boost it’s just going to roll coal, however the compounds should help by providing boost very early.

[Blablachef]

This i appreciate, looking forward to see this build!

[evilhighway]

Gotcha I am no where near a diesel expert.

[mitbes]

Turbo layout and hot side piping done, getting this printed using 316 stainless. Not something I have done before but very interested to see how it turns out.

Exhaust manifold, with ports for 3xEGT and wastegate

Dump pipe from GT06 to GT12 with wastegate port

Also printing the LP crossover from GT12 compressor outlet to GT06 compressor inlet, which will be SLS glass filled PA12.

Using a tial copy 38mm wastegate for the HP bypass, as the GT06 internal gate is tiny and when I clock the turbo I will lose the wastegate actuator mount anyway.

Also, engine adaptor plate is out for manufacture as well.

[mitbes]

Also if anyone has a l200 k frame in southeast Qld I am keen to buy.

[mitbes]

Update, stainless steel 3d printed turbo manifolds are done.

Bolted up nicely:

V bands fit up was pretty good, needed to to a little grinding to get it to fit right. With all the tolerance stack-up I was pretty amazed these lined up and clamped down.

Also adaptor plate fitted to engine:

And the Kubota bolted to the L251 gearbox:

Next job is to get the flywheel customised, have it all drawn up so might get it done this week.

Another interesing thing I have got coming is a LDV water-air intercooler:

I have removed the end tanks, and will be doing custom 3d printed end tanks to suit where I want the piping.

A mate has been really cooking on these end tanks:

[evilhighway]

this is coming together so well.

[evilhighway]

@Butch_Butcher this one?

[Butch_Butcher]

Yes, indeed. Thanks

[Butch_Butcher]

[quote=“mitbes, post:3, topic:7233”]…pricing from China is incredible…[/quote]How incredible? What did China want for casting these?
Having looked up a video of a 3-D stainless steel object being cast, I looks like some robotic arc welder doing the job. Which makes me wonder as to how 3-D thin-wall extractor/headers are made.
The following video shows how to scan your engine bay for robot-made equal-lengthed extractors. I didn’t have time to watch the video in its entirety. Therefore, the actual manufacturing process might be revealed, near the video’s end.
Perhaps, like sheetmetal leading and oxygen-acetylene torch brazing and even cutting, tube-bending appears to also end its life as a skilled trade:

Designing V10 Headers Using The MIRACO 3D Scanner! - Ford V10 4V Build Ep. 18

[mitbes]

These are 3d printed from 316 using the SLM selective Laser Melting method. Basically a fine 316 powder is deposited on the bed and then the laser melts the powder to the previous layer. This method went from being $10,000 a part to $200 a part in the last few years, I did not expect it to become so affordable so quickly. The custom manifold was cheaper than a stock exhaust manifold from Kubota.

[evilhighway]

Wow that has come down in price. I looked at it a few years ago and it was really expensive. To see the prices now is nearly unbelieveable.

[DAIWRC]

Great build so far! Thinking out of the box. Cant wait to see how it performs