Modding A V6

As some of you know, Iam the proud owner of a post-XM model V6 engine, the 210hp version.

Unfortunately it doesn't work without the correct engine ECU (Bosch ME 7.4.6) to operate the VVT, the six individual coils stuck on the sparking plugs, the electric throttle and injectors etc.

The C5 site gives the following info:

"V6 Engine (ES9J4S)

The 2,946 cm3 ES9J4S engine features six cylinders mounted in a 60° V configuration. It has changed considerably with respect to the 1996 version mounted on the XM and Xantia, especially in the design of the combustion chambers and valve gear. Friction has been reduced throughout, and the total weight has been reduced by 10 kg.
These technical advances bring the following major improvements :

1. eight per cent increase in maximum power output compared with the earlier version, to 152 kW (210 bhp) at 6,000 rpm, and 6 % increase in maximum torque, to 285 Nm (29 m. kg) at 3,750 rpm, with a 10 % increase in low-end torque, to 260 Nm (26.5 m. kg) from 2,000 rpm ;

2. lower fuel consumption under identical driving conditions ;

3. improvement of one litre per 100 km in the standard combined cycle ;

4. oil-change service interval lengthened to 30,000 km,

5. and spark-plug change interval lengthened to 120,000 km ;

6. compliance with Euro 4 emission limits without any additional equipment.

Engine design changes include the following :

a. variable valve gear, with the inlet camshafts incorporating variable timing ;

b. modifications to combustion chambers and inlet manifold ;

c. new multiple-jet injectors ;

d. electronic throttle ;

e. six ignition coils ;

f. flexible” engine flywheel ;

g. compliance with Euro 4 emission limits, with two pre-catalysts and four lambda sensors ;

h. additional water / oil intercooler."

So I'm sitting in my garage, looking at this lump and thinking that apart from supplying me with a spare alternator, air con pump, starter and of course the 4HP20 autobox, it's not much use. Of course I can practice belt changes and take it apart to see what makes it tick, just for the fun of it.

And then I realised that performance and economy is improved at the lower rev end as well as the top, and this improvement takes place with the camshafts in the unchanged position.

So I wondered, what if I swap cylinder heads, fit the existing ignition arrangement and manual throttle valve, and drive it with the existing ECU? Or even swap the whole engine and couple it to the old ECU? Of course the VVT won't work and I'm not sure about the injectors.

What do you think? Am I barking up the wrong tree, or just barking mad?

Derek

Hi Derek

Sounds like a fair bit of head scratching will be needed here, but that's the point right?.
I suspect the increase of performance comes solely from the heads, manifolds, injection system and the fact there is one coil per cylinder, then they have uprated the cooling systems to make sure it can all cope.
I notice the new un has m/j injectors too and i would say with almost certainty that any of these components will need the ME computer to keep them all dancing together so to speak.
If you put the heads onto your block the first things i would be thinking of are,
Do the oil and coolant galleries line up
Are the piston crowns compatible with the shape of the combustion chambers
can you make the management systems work with your block and the sensors available.

Would the vvt be ok left inoperative do you think? if its electronically controlled it should be..............

D

Hi Dean,

"Do the oil and coolant galleries line up"

That is a very pertinent point , and I'd have to take a head off each engine to check !

"Are the piston crowns compatible with the shape of the combustion chambers"

As they've changed them, probably not.

It's purely an academic exercise at the moment, but your answer has turned my thoughts towards changing the complete engine and then adapting it - changed injectors, ignition layout, throttle body - to run on my ECU. The camshafts should remain in their slow speed (up to 3,500rpm I think) mode which is probably all I'd use. If at some future date I managed to locate a later ECU then it would be easy to modify to full spec.

Time I started looking for an engine crane

Derek

At a rough guess I'd say a massive amount of work, with a dry build to check piston/block heights, very precise head chamber volume measurements and then a check of the valve protusions with the head in place using the special 'blue-tac' gauging material. Then if all that worked probably a custom ECU map to make it run and hopefully pass it's emissions test. Pretty much what Lotus and Cosworth did to Ford engines.

It would be one hell of a project though.

Steve.

Hi Derek (and Steve)

Is it *that* difficult to find the appropriate ecu to match and stuff the 210hp gear in one piece in your car?? Sorry if u have already said elsewhere u've tried to locate one, I haven't spotted it.

I'd think a few questions on german or french ebay would be fruitful. Also, I see plenty of pug407 coupe engines for sale, surely someone will have an ecu-only? Or try a french parts braker/stockist?

cheers
George

What I was actually thinking is that the engine will be an hybrid of sorts. Maybe the injectors, etc would have to be paired with the ECU (if it is possible even) and then if it could be made to run the mapping of the ignition, fuel, other sensors would perhaps need heavily modifying. I don't know if you've looked into ECU map tuning but it's one hell of a lot experience to do it right.

Anyhow how are you George? Good to 'see'you on the forum! (Have a quick glance at my signature!)

Steve.

Hehe, u r back to XMs!! And a nice one, TCT+LPG, a very good combination! Hope u sort it out soon (I guess it'll have its glitches!) and take many happy miles from it! I saw elsewhere u r becoming an Elit expert, that's great!

cheers
G

Hi Derek

I'm with steel city here. Why not try to find the correct ECU and fit the engine complete? That would seem to be the least hassle and it would give you all the "advantages" of the new engine and with the least hassle.

Or.....K&N filter, stainless low back pressure exhuast, engine remap and a tin of friction reducer (slick 50 etc...). That would probably give you more BHP (if you are interested in these things) with almost no hassle.

BTW have you got a bit of extra time on your hands. If you are like us you 24v doesn't cover a huge annual mileage (ours about 5-6K) hence fuel consumption isn't my greatest worry and I think that it would be a good day before I could tell the difference between 8-10% more bhp.

However - the same engine in the Clio V6 produces 245bhp and the Top Gear Espace produced about the same. Hence there seems to potential in the engine.

Cheers

Tony

You're all correct of course. Like you Tony, I'm not bothered about fuel consumption and | seldom use anything approaching the full performance I have with the existing engine, so what is it with me?

I suppose it's the "OK, I've fitted the multi-fuel stove my wife's been pestering for (sorry Dean), I've fitted the condensing oil boiler and between them reduced my heating oil consumption by 50%, both XMs are working well, all outstanding jobs around the house are done, the garden is in hibernation, what can I do next?" syndrome.

That and I don't like something not being used.

I think I'll follow your advice and concentrate on trying to find the correct ECU. George, I'm handicapped in searching non-UK sources by a comlete inability to master other languages; I found it impossible to progress beyond "Noch ein bier bitte" and "Ouvre la fenetre" (complete with those alien accent things!)

So for the time being I'll concentrate on getting the spare engine and gearbox ready to instal.

As an aside, has anyone any experience of the engine stands that are available on ebay? they seem to have a rotating plate with four protruding studs. do the fit onto the bell housing mounting holes?

My thanks to all of you.

Derek

This post has been edited by DerekW on February 14, 2009 12:08 am

Further thoughts. Isn't it the engine ECU that the anti theft code talks to? The probable source for an ECU would be Peugeot and if I remember correctly the code on them is in a chip in the ignition key.

Derek

Hi Derek

I think you will find that you V6 engine will overload the average engine stand. You might have to purpose make a stand from angle iron. Have you tried the engine supplier to see if they still have the ECU. There is a specialist PSA V6 breaker in Chesterfield that regularly puts on ebay.

John

This post has been edited by xmexclusive on February 13, 2009 06:30 pm

Hi D

I've purchased many times from ebay-Germany for my XM and all business has been in English, I don't speak a word of German either, no problem at all!! Once, I was lost in a German airport and I addressed to a baggage-related worker who I was amazed to discover spoke very functional english!! French are similarly okay but not to this degree, I write in French whenever I enquire about anything on french ebay, once a guy replied me in English without me even having asked to -he prob saw my feedback and realised I was in the UK-!. So go on, no hesitations at all, and I think especially Germany will have a few ESJ4S ecus!!

cheers
G

Thank you John and George.

I'd certainly be nervous about hanging up that lump of an engine by the back of its crankcase, if that's how it's done.

I'll follow your advice regarding German ebay, George. I'd assumed that if the engine supplier had the ECU he would have offered it with the engine, or maybe he maximised his profit by selling on a separate listing. I wonder why he didn't take the gearbox off and sell that separately.

Derek

Hi Derek,

My dad has a 406 Coupé with the later VVT engine.

It is a bit quicker, the torque curve is much smoother as it doesn't surge power at around 4000 - 4500 rpm like the older ES9J4 engine does.

One thing to remember is the 406's only received this engine when they were face lifted, and like you said the transponder chip in the key talked to the ECU and turned off the immobiliser as they were never fitted with the code pad.

I'm assuming from your last post you already knew that but thought I'd mention it.

I'd of thought you should be able to pick up an ECU from the 406 Coupé fairly easy on eBay, if you do though you NEED to get the transponder chip from the key for the vehicle otherwise the ECU will be permanently locked.

If you go ahead with it you might need to find a way of sticking the transponder somewhere inside the XM key or to make another keyfob that will house the transponder.

Regards

David.