2.1 xud

[samass]

Just a quickie, which vehicles had the 2.1 xud in them?

[Sambarker]

Citroen xm, xantia, 406, 605

[samass]

Cool thanks, what sorta ages we looking at?

[Sambarker]

1996-98?

[Matt]

Google it you shlaaaaaggggggg!

[samass]

Cheers Sam.


f*ck off Matt, you wanker.

[Mountie66]

just did my 306 put a 2.1 in...just exhaust work left to do.Is a big job and a fair amount of changes to make.Have to relocate turbo to where battery sits,and battery to the boot as there is no room behind engine for a turbo...And need a bosch pump with 11m.mine has a 12mm in..

[THE_Liam]

Didn't the 806 and Ulysses have it as well?

[Ed Doe]

^^ Yes Liam, some did

[samass]

no worries, i'll only be molesting it for parts, not to put the engine in my car

cheers for the help, now i know which ones to look for while im at the breakers next

[THE_Liam]

It'd be interesting to do this swap and see what the potential is. People don't seem keen on it but maybe that's because there isn't an established group of mods/parameters to work to, surely a bigger XUD is only a good thing? Does anyone know what the capacity difference is caused by? Bigger bore, longer stroke or both?

[samass]

well i know the stroke is around 96mm, which is longer than the 1.9, dunno about the bore tho

[Midnightclub]

IIRC it's because the head doesn't flow as well and has a much longer stroke making it less 'revvy'

[samass]

still seen it done a few times tho

[Dicky]

I personally think these are pointless engines to convert, I had a play with one when I had my staged 1 diablo and pulled 3 cars on it when he had a FMIC and Exhaust with tune.

Just my opinion from that

[THE_Liam]

Hmm....

Might try it at some point, although I think my next 306 will be a HDi anyway...

[Ruan]

The theory is that they'd be a better engine, however in reality, the 12v design was simply an emissions thing more than a power thing... They over complicated the head design with hydraulic lifters, which is one of the XUD9s main plus points (60psi at the manifold before any valve spring issues - and they tend to keep their clearances quite well considering how many they'll do without needing adjustment...)

I've seriously been looking at it as an option recently since I'm changing my engine, but it's not worth the hassle and ballache to change to when there's other parts that will more than likely cause issues when pushing for more power... Remembering also the 96mm crank will reduce it's happiness to spin fast, you send the mean piston speed up even more, combined with the fact you've got 85mm pistons, more weight on the end of the conrod, accelerating and decelerating to and from higher speeds, when they're VERY heavy piston/rod assemblies as they are...

240hp has been seen a few times with indirect injection engines with less capacity than ours... Displacement is nothing without better volumetric efficiency...

Say our engines are 75%VE at peak, not including boost... That gives us an actual displacement of around 1430cc...
Say the 2.1 ALSO is 75%VE at peak, excluding boost... That gives us an actual displacement of around 1566cc...

If we could bump that on an 8v 1.9 to 85% - you've already bumped that to 1619cc...

Then consider that possibly the 2.1 heads in reality don't flow as well... By the time you've finished getting a 2.1 in, you're nearing what you could have done by just improving head flow on the 8v 1.9... but you've got all the issues of the 2.1...

I'm no expert in head porting or head flow, but that's how I see it anyway...

[THE_Liam]

Oh so the 2.1 is 3 valves per cylinder? I didn't know that, I thought itd just be a stroker version of the 1.9...

[Ruan]

Nope, 85mm bore, 96mm stroke, 12v head, 2 inlet, one exhaust (but the exhaust valve is tiny...), hydraulic lifter...



XUD11ATE head on top, note the tiddly little exhaust port...

If you're interested, that's a DK5ATE head below.

[THE_Liam]

I can see the problem right there. Too small an exhaust port, and not much meat between the valves to bore them out, plus if yank V8s have taught us anything it's that lifter wise, solid>hydraulic...