[quote=“mitbes, post:1, topic:7233”]…At high RPM it’s going to choke…[/quote]Is the 4000 rpm the highest you plan to go with? If not, you may wish to take into account that this is a pushrod engine initially designed for high-torque stationary and agricultural use, possibly lacking the precision revolving mass balancing required for high speed operation. You may then need to replace the valve springs with stiffer ones and maybe have aluminium pushrods delivered [quote=“mitbes, post:18, topic:7233”]…The custom manifold was cheaper than a stock exhaust manifold from Kubota…[/quote]Is that to assume that Kubota never turbocharged this particular engine? If they indeed have, it would have been inferior to the one you have had cast, simply because yours will reduce turbo lag to a minimum which is otherwise an unneccessary feature for the applications it was designed for. So, if you have yours patended, Kubota must first request your permission for producing these types of conversions for automotive use
Hey mate, I will spin it up to whatever the governor lets me but don’t really plan on going much more than 4000. These engines have a very big performance following in the USA - google “Diesel garden tractor pulling” They mostly use the D1105 or D722, which are effectively the same as what I have, and spin them to 6000+rpm on standard internals and pushrods. With aftermarket gear they are getting 10,000rpm which is ridiculous for a little diesel. They drill the governor weights, to make them lighter, and increase the spring stiffness of the governor spring. They are also running 4x the fuel I am planning, with their pumps calibrated to do 100-120cc of diesel and turbos with 75+psi of air.
I have no doubt the internals will be fine for what I am trying to do, the unknown will be head gasket and cylinder head survival. Hopefully my huge electric water pump and excess air will keep it cool.
Diesels generally run cooler, because they burn fuel almost completely.
Here, a couple moral-boosting videos 
:
Sorry if I have missed the detail but where did you get the manifold printed again?
Through craftcloud3d. Google for a 10% discount code. Other option is jlpcb, worth checking both as the pricing seems to fluctuate.
Kubota two-bangers were installed in French mini cars. In the second video, the owner tweaked his engine to do over twice as fast as original:
Brilliant road trip that was.
Now imagine that 2nd one with boost.
We could be on to something here:
Never knew about these - thanks for the pointer. Certainly helps with motivation.
I have actually made a bit of progress, flywheel is machined to suit the Daihatsu clutch and the intercooler is all plumbed in. Just waiting to get my workshop space back, end of October, then I will rip the EJ out and do engine mounts.
Also, I mentioned that I was on the lookout for the 950cc version, and I managed to pick one up.
Donor vehicle:
I just caught these videos. Subtracting the weight of that heavy flywheel, timing gears and crankshaft assembly, this has to be an aluminium block and head, in order to weigh-in lighter than Daihatsu 3s:
Been a while, had a few side projects take up time over the last couple months but the diesel is now back in the workshop.
EJ gone:
D950 test fit:
Clearances look really good, will hopefully be able to get the gearbox in the same location so I don’t need new driveshafts again. I only recently did the shafts to suit the 4x100 conversion. Engine is much shorter than the EJ as it is pushrod. I will also lean the engine back as far as I can. Over the last few months I have collect 4x of these 70mm stroke kubotas. I have D950, D850 and 2x D750 so I am ready to kill a few engines finding the limit.
They are steel. It’s a very small engine, dimensionally smaller than an EJ in every way. I did weigh them bare, EJ was ~63kg and the kubota was ~54kg.
If you use the original gearbox mount to hold the gearbox in the right spot and then work out the mounts front and rear mounts, then you should be ok with the drive shafts. (in theory)
I didn’t look close but it seemed the later EJ L251 gearbox has a different mount to the L200 EF? I maybe should look again. When people put the EJ box into a L200 do they use the original mount from the L2 or from the EJ donor?
I don’t have the L251 mount, I just got it as a bare gearbox so can’t compare.
Yeh it is different lol I forgot you are using the L251 gearbox. I have used one before and I used the l200 mount and just made a plate and bracket that mounted to the box on the rear side near the end of the box. My description is bad sorry.
So I would get it where you have your shaft’s in the box etc and the move the engine and box to where it will work with your current shafts. and the work your mounts from there. Probably alot of assembly and disassembly but I think it would be worth it.
Righto engine mount prototypes are done. Will use/modify these to suit. Was able to use the EF engine mounts all round, hacked the EF gearbox mount a bit to suit the L251 box. The front mount just needs a 15mm spacer, will use 2 layers of 8mm steel laser cut with the appropriate holes. Rear mount will need a plate added to engine side as well, which I will weld all around the EF mount. Engine sits really nice, good clearance all round.
I am going to need new driveshafts as where I want the engine is across to the passenger side, and also the L251 diff must be offset a fair bit compared to the EF diff. These things combined make up for about 40mm of driveshaft mods, shorter on passenger side … longer on drivers. Lucky I have a set of sirion shafts which are both longer than I need so I can cut/weld them to the right length.
Will need to remake the longitudinal reinforcement that runs under the engine as it interferes with the sump, I will do this last once I know where my exhaust and shift linkages go. Have also ordered new mounts for front and gearbox as they are cooked, pretty much collapsed.
Pics:
You could save plenty of weight, through opting for a 15 mm thick aluminium plate which would be much easier to trim, not requiring laser cutting. Wasn’t your oil filter located right where that plate would’ve gotten in its way?
excellent work mate well done
While searching for a replacement ED-20 camshaft, I stumbled on a Daihatsu Diesel similar to your Kubota. here, a 950 cc Toro 5xi 523 dxi garden tractor engine:
Here’s one in some sort of vehicle:
This one’s already turbocharged:
Youtube algorythems are mind-reading:
Details on fabricating fuel pressure and boost devices, regardless of what brand vehicle a Kubota Diesel is to be installed in:
He ended up turbocharging it, instead: