1.9 into 2.1?

mrbump · Post by **mrbump** » 31 Jan 2007, 21:31

Hi,

Am i correct in saying that you cannot fit the xud9te 1905cc diesel 8 valve cylinder head onto the xud11ate 2068cc block? If i remember correctly the coolant passages are different on the two engines, as is the belt.

What I am wondering though is would it be possible to fit the crank rods and pistons from the xud11 into an overbored xud9 block? The overbore would be 2mm (from 83mm to 85mm) which can obviously be accomodated as essentially it is the same block. The crank will give the stroke another 4mm.

Are there any differences in crank journal size or crank/block clearance that need to be considered?

mbunting · Post by **mbunting** » 01 Feb 2007, 10:49

mrbump,

The 2.1 is 12 valve, so this could cause you a problem, also the coolant design is different, which may also include the head.

Don't forget the manifolds as well, they're huge.

If you're thinking about what I think you're thinking about, then let me re-assure you, the 2.1 engine is HUGE in the 406 bay, the head is also HUGE, and I think you'll find physical clashes between the head/manifold and the bulkhead in your cars.

Mat.

mrbump · Post by **mrbump** » 02 Feb 2007, 15:35

Hi,

I am not thinking about transplanting the whole 2.1 engine, only the crank, rods and pistons into an overbored 1.9 block.

What I am really looking for is the crank dimensions for the 2.1, if they are the same as the 1.9, then it can be done. The blocks are the same height, only differennces would be the stroke of the crank to give the extra stroke.

If anyone has the haynes manual for the 2.1, could you give me the main bearing diameters please?

jeremy · Post by **jeremy** » 02 Feb 2007, 18:02

You could try the PR net and see if the shell bearings are the same. Figures from Haynes may be a bit suspect - unless given to a great number of decimal places - looking through Glass's technical information (I only have 1989 edition) I see tiny differences between apparently similar bearings (ie petrol and diesel) which may be to deter wrong use.

These sort of things have occurred to me as an interesting challenge - but what's interesting is the struggle Citroen had to get 110 BHP out of the 2.1. What I mean is that the 12 valve head wasn't made for fun - so simply enlarging the capacity didn't produce the necessary power. Multiplying up the 1769 BX Turbo diesel output of 90 BHP gives nearly 110 BHP - but something seems to have got lost on the way to the 1905 cc version - and I can only think that it couldn't be made to breath well enough with 2 valves - hence the use of 3.

So - there is I suppose a possibility that you do all this work and don't get the output.

mrbump · Post by **mrbump** » 02 Feb 2007, 20:45

Hmm, not sure about that. My 1.9 at the moment has more than 110 hp and the valve size is certainly large enough to support flows of over 200hp in theory. I know of more than enough 1.9's with 150hp and above.

Yes, the bearing size would be enough to tell if the crank would fit.

regards
greg

whats PR net by the way?

AndersDK · Post by **AndersDK** » 02 Feb 2007, 22:19

mrbump wrote:... whats PR net by the way?

http://www.citroen-pr.net
Citroen parts data base on-line. You can register, instantly get the retail price, and order parts on-line.
Its a huge parts database with exploded views on all recent Citroen models. Earlier models further back are not in the database however (D-series, GS, CX etc.)
Only important information NOT found is the electric schematics

mrbump · Post by **mrbump** » 02 Feb 2007, 22:37

Oh, I do remember that one now!! THANKS!!

mrbump · Post by **mrbump** » 02 Feb 2007, 23:51

Mains are same size (edit i mean part number) on xud9 and xud11 which means has same size journals. Just as long as the crank doesnt hit the block, a 2.1 litre 8v xud is entirely possible, although I think a custom gasket would be needed with larger bore size, as the 2.1 one has different passages. Copper gasket with o-rings would be best bet. Although using the crank alone with 1.9 rods and pistons would give a theoretical 1991cc, without overbore and standard 1.9 gasket could be used - assuming bigends are same size.

Now who is going to sell me a 2.1 turbo with a blown gasket?

By the way why are all the XM's listed as having a 2088 cc engine? Surely that should be 2068cc?

And also the 1769cc turbo engine is not 90bhp it is 78.

cheers

jeremy · Post by **jeremy** » 03 Feb 2007, 08:20

The 1769 cc Turbo-diesel was 78 BHP in the Peugeot 205 Turbo - when it did not have an intercooler. In BX it has an intercooler and is variously rated at 88 or 90 BHP and 133 lb ft torgue.