One for the turbo boys.

[TomSaintJames]

Hello all,

Had a rubbish realisation yesterday. My BX GT has been not running, there's fuel, there was no spark but borrowed a known working coil and ignition module off of another 1.9 carb engine (all other ignition parts had been replaced with quality new bits last summer) and it still wouldn't start! So I looked at the cambelt, I had taken off all the guards to see how big a job it'd be to change myself and got no further. So I noticed how loose the belt was, poked it with my finger by the cam pulley and it fell off! Bloody thing has snapped. So, consensus is that it snapped after me turning it over yesterday, as all cranking attempts sounded normal (chug-chug, not just starter spinning away). But there is still a chance the valves are busted. So I have had an offer of an exceptionally spanner handy chap to put the new belt on and pressure test it.

So, I finally get to the question bit! When it's on the orad, i'm not sure how long I am going to be satisfied with 105bhp of torquey citroenness. I have been reading on the 205/309 scene about turbo 1.9's. It seems you can bolt on the turbo and manifold (and most other gumph) on most/all of the 1.9 8v's. The 2.0 TCT head apparently is of quite superior design to the DFZ (105hp) and D6B (130 GTI) 1.9 heads, bigger valves, better flow, better designed combustion chamber and spark entry. I would like to keep it carbed, love the sound a carbed engine makes - and I am a total electrical virgin.

It depends on my current block's condition on what happens. It's done 60,000 well cared for miles but not run for the last 10 or so years. If the block is buggered then i'd like to put a TCT head on, if the head is fine, then i'd stick with it and use the TCT manifold and turbo assembly. I'm not after big power, even the TCT's standard 150 would be fine, less also fine as the BX isn't heavy. It would be cool to keep up with 16v's though

Technical stuff. Here's my thinking:
TCT exhaust manifold, with turbo and wastegate
TCT pipework (oil feed etc)
BX TD pipework (air hoses etc)
BX TD intercooler
TCT head (would need french XM carb inlet)/DFZ head (current carb in a boost proof box)
BX TD radiator with double cooling fans
Custom twin exit exhaust system (love the look of these, could get a very retro pair of tailpipes, that'd help with the BX's standard restrictive system JZ1

The carb would need to be in a boost proof box to stop it leaking at the seals due to the increased intake pressure, and i'm not sure if it should be blow through or suck through. Not looked this bit up yet. What do we think? Is it possible? If all the bits bolt on and are all compatible as people suggest, would it be buggered by the the carb, and trying to get it running properly? Could a bigger, better carb be used perhaps? I'm reluctant to go EFI due to the extra effort involved, and as i'm not going for loads of power then i'm not sure it's worth it.

Some references.
http://websworld.org/marcel/309/tech/heads.html
http://forum.205gtidrivers.com/index.ph ... pic=117232

Thanks!

[Duke]

I must say that personally I would leave the BX standard.

I'm not one of these "it must be original" car anoraks as I do like a spot of modifying and will be doing some to my XM, however to the BX I don't think it would be right. Obviously it's your car to do what you want to but when we had that BX GT it was a lovely original car and IMO it would be great to preserve it for the future in it's current condition, which from memory was very good.

The engine in the GTs are torquey units that like to rev - they're no powerhouse however have adequate performance for their age. Getting the original carb set up right including the autochoke will make things better. The BX GTs are probably the most un-GT like car around, just a few spoilers and GT badges and that's pretty much it.

Personally I'd see what's what with the current engine and hope there's not a huge amount of damage done, rebuild it and stick with that and run it for a while to see what you think of the 1905cc engine in it... Tweak your TD perhaps or look out for a BX 16V, or find and tweak a TCT XM...

The MK1 BXs are getting rarer and rarer and IMO one that is in the condition like yours should be preserved...

Not much help to your original questions and it's up to you of course but that's my two penneth-worth...

[Dieselman]

The broken belt has probably broken the camshaft but not bent any valves. They are designed to do that.

[citroenxm]

Not sure about that on an XU petrol engine Will...

They have 5 cap bearings not three like the XUD.. They are held in place a bit tighter.. The heads are also NOT a flat design head like the XUD either, they have a recess, however, they are still NOT a clearence engine. My guess is its more likely to have bent the valve stems, rather then the other. The valves are flat directly in relation over the piston. So I think more bent stems.. Ive not seen a broken XU shaft yet..

[robert_e_smart]

Xu petrol will bend valves. Seen this on a 1.8 xantia.

[citroenxm]

Not saying they don't. I was trying to say they don't break the cam shaft like the xud 8v engines doo...

[Dean]

You usualy loose all 4 exhaust valves in a belt failure with t&xu engines, as it was done cranking you may have got away with it.

D