Quick question

Far too much work involved, unless you are a real expert, have lots of time and money - I wouldn't bother. The front of the car would nosedive!

Well, no. The 205 came with a 1.8TD anyway...

Yes, but the 106 was never fitted from the factory with any of the XU engines AFAIK. The TUs in 106s/Saxos/AXs are all much smaller. 205s got XU and TU engines.

I don't know if a 1.9TD will go in a 106, my guess would be no as the engine bay is *tiny*. Gotta be worth a try though. (c:

I'm sure you could make it fit, but it certainly wouldnt drop right in, all the mounts are different, the exhuast will be different, and the gearbox is different to name just the major parts. Far too much work for very little benefit. The Xantia 1.9TD lump into a 205 TD would be a better choice, and that will bolt straight in.

That, children, is what we have angle grinders for :-)

How much benefit would there be though? In terms of:

Power? Torque? Economy? Tuneability?

AFAIK the 1.8 litre XUDs (even the normally aspirated ones) shift reasonably well as they are, so short of a 1.8 spectacularly and unexpectedly dying and a 1.9 being available cheaply, what would be the point?

Basically, tunability. The 1.8TD in the 205 doesn't have an intercooler, so increasing boost quickly increases intake temps, so power potential isn't that good. The 1.9 does have an intercooler and is tweakable to ~115BHp fairly easily with fuel pump and boost mods, which is a fair whack up on the ~80BHp of the stock 205. Should be rather good fun actually.

See ATC's reply. It's probably easier to get an engine with intercooler and the appropriate fueling already set up than it is the add an intercooler and adjust the fuel on the standard 1.8 engine. Of course, you could easily use a 1.8TD intercool'd engine from a BX (or 405?). The 1.8 is reputed to be a bit stronger, and the head gasket going isn't quite so common, in reality I doubt there's much in it. And I think the 1.9s had slightly bigger turbos - I put a 1.9 turbo on my original 205DT and some minor adjustments of the bulkhead was neeeded (read: BFO hammer). Whether it has a power benefit or not is a different matter.

One day I will do it - 205 TD with intercooler. Maybe when the BX has bankrupted me and I need something cheap to smoke around in!

Lay some newspaper in the boot in case of oil spills. It should fit if you put the back seats down. Probably need two people to lift it though.

Lol, thanks everybody, the reason I asked was that my Xantia just shot it's drivers side strut up through the bonnet and a 106 came up on freecycle.