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Tue Sep 20, 2011 5:39 pm

I have a TDI head and a JX bottom. I tried them together today and it actually seems to work. There's an oil return in the head that's missing downwards, that could be plugged and routed externally though.
Except that it looks like it's more or less a doable project. I might have to try it...

Tue Sep 20, 2011 5:43 pm

:lol:

Umm, OK, so where does the fuel get injected, exactly?

Tue Sep 20, 2011 5:59 pm

Yeah, not gonna work with JX pistons (no combustion chamber) and a resultant 75:1(?) compression ratio. Get four 1.2 TDI pistons and install them in the JX and you'd have yourself a 1.6TDI.

Oh wait, the JX uses mechanical lifters, so you'll need to deal with the oil return in the head and the coolant channel in the block that matches up with it...

Wed Sep 21, 2011 12:05 pm

Andrew A. Libby wrote: Yeah, not gonna work with JX pistons (no combustion chamber) and a resultant 75:1(?) compression ratio. Get four 1.2 TDI pistons and install them in the JX and you'd have yourself a 1.6TDI.

Oh wait, the JX uses mechanical lifters, so you'll need to deal with the oil return in the head and the coolant channel in the block that matches up with it...

Ah, the compression ratio, didn't think of that. The oil return, I could plug in the bottom of the head and then re-route in on the outside.

The thing is, I don't know why I should do it or what I would benefit. But it would for sure be a Franken build worth its name and that is a reason good enough for me. :D
Might not do it with this engine though, the head is soon back totally fresh.

Hmm... The Golf diesel has hydraulic lifters...

Wed Sep 21, 2011 1:45 pm

Starting with a hydro block and it's a bolt-on. Just get proper TDI pistons with the right bore and wrist pin height and you're done. No real point tho, IMO, other than bragging rights. A 1.9TDI will deliver the same fuel economy if driven at the same acceleration rates and the 1.9TDIs are readily available already assembled.

Thu Sep 22, 2011 12:08 am

If you can get you hand on a KY 1.7L NA engine from a T3,the head should fit perfectly on it :wink:

I know the other way around have been done by a friend:TDI block and KY cylinder head with 1.9 AAZ TD pistons :lol:

bye!

Thu Sep 22, 2011 7:40 am

KY is still a mechanical lifter engine so you'd need to deal with the blocking of the extra oil return in the head and the blocking of the coolant channel in the block that lines up with it. That would just be a de-stroked 1.9TDI. It could certainly be done, I just don't see why someone would do it.

Thu Sep 22, 2011 10:24 am

Andrew A. Libby wrote: It could certainly be done, I just don't see why someone would do it.

I agree, there's really no reason. But now it's actually getting hard to find a new head for the JX in decent condition. And if I had to choose to convert another IDI head or a TDI head I would go for the TDI-head. I believe that the lower temperature and lean burning would be good for a 50 deg install.
Might be interesting to try it out...

Thu Sep 22, 2011 11:50 pm

Andrew A. Libby wrote: KY is still a mechanical lifter engine so you'd need to deal with the blocking of the extra oil return in the head and the blocking of the coolant channel in the block that lines up with it. That would just be a de-stroked 1.9TDI. It could certainly be done, I just don't see why someone would do it.

Not really any interested but having the parts already on hands and making it work :lol: :lol:

JX heads can be found new,buy a good brand like Kolbenschmidt or AMC :wink:

Fri Sep 23, 2011 5:53 am

The only reasons I've looked into a small cc TDi engine is if we could change the road tax band on our vehicles but afaik, you can't change it.

The other reason is economy. I looked into small TDi engines from the Audi A2 etc... the 3 cylinder 1.4TDi as it has around 70bhp and produces up to 70mpg within the factory cars....

However, looking at everything to do with modern TDi engines = low rpm, light vehicles which are more aerodynamic and nothing like our T3 vans.

At some point in the future, I am going to revisit this with a stock Syncro van which will be lower, run not as big tyres as Limey and will probably run a stock PD TDi or more modern 2.0 16V TDi with the aim of just being very ecomonical. It will probably be a multivan rather than a crewcab or singlecab as they're more aerodynamic (if a T3 can be such a thing).

The thing that is holding me back at present is the inability to go further than a 4.57 (which are just about impossible to get hold of now) and a .70 4th gear. You can get 4.14 final drive ratios for 2WD. This makes sense but in order to get the mpg, you need to get the rpms down to similar figures that modern cars are running. I know that a lot of cars are now running 70mph at 2,000rpm.

MG

Fri Sep 23, 2011 6:48 am

Aside from the fuel economy hit from being heavier than a 1.4TDI, you could get the same fuel economy from a 1.9TDI that was detuned to the hp/torque of the 1.4. It's easier just to push less hard on the go pedal, tho.