|
Talbot Express – Engine Upgrades (Peugeot J5, Citreon C25) |
||
|
|
||
|
Before considering any engine modifications it is worth asking “What is holding the van back?”
Once you’ve identified this you can begin to quantify the theoretical difference each modification will make and do a feasibility/cost/benefit analysis. This is old-school technology though, and the old adage bears true…. “there’s no substitute for cubes” (Namely if you want more power the most effective way is almost always a larger capacity engine”!
So….What is holding it back
1. Weight
2. Air resistance
3. Rolling Resistance
4. Lack of Engine power 4.1 Intake:
4.2 Combustion
4.3 Exhaust
Priorities:
Looking at the design of this engine I’d suggest that (in an ideal world) the Tuning priorities would be:
With this lot you are looking at several hundreds of pounds for a potential power gain of only 10-15% tops. This is negligible and hardly worth the time or money unless you are very enthusiastic! However, you don't ahve to go the whole hog and there are other options:
Options for Increasing Power:
in reverse order ..... |
||
|
Change the engine/transmission to a completely different unit: |
||
|
This is the most expensive and difficult area as there are a lot of issues to be addressed when moving to different engine entirely, e.g. :
To my knowledge there is only one tried and tested conversion on the market. This is a conversion to a Renault Espace 2.2L petrol engine and gives almost twice the BHP. The conversion is marketed by Delphin Designs but is very expensive at £3000 (2006 price). I assume this includes a second hand engine and any other item required but you'll need to check. I believe Delphin will supply just the adaptor plate (Renault engine to Talbot Transmission) for approx £600 should you want to go down that route yourself.
If you do decide to pursue this option please let me know how you get on (and some photos) so I can include it here for the benefit of others.
|
||
|
Change the engine/transmission for a unit from a comparable model (i.e. another TE) |
||
|
Before you go down this route consider the following.....
In terms of power (PS) the petrol unit
produces 85 while the turbodiesel unit manages 95. The naturally aspirated diesel engine is
less powerful (75) and has less Torque than the petrol version so is not worth consideration.
Personally I would not change a working Petrol engine for a Diesel conversion as the benefit of higher MPG is outweighed by the benefits of a petrol engine. If fuel consumption is your primary reason for considering such a drastic (and expensive) swap then an LPG system might be a better option as this gives comparable (or better) MPG with all the benefits of Petrol performance and much less harmful emissions. However, even with LPG I would encourage you to consider your annual mileage with respect to the "total cost' of holidays. You may find that the fuel cost is actually comparatively negligible overall.
For info.... I opted to fit an LPG system to my van a few years ago and it has been a major improvement. Power output is comparable to its previous well-tuned petrol performance, the engine runs very smoothly indeed, and cost per mile has almost halved so I am more relaxed and using it more. The conversion will take 2-3 years to pay for itself. See the LPG page(s) within this website for more info on the conversion
|
||
|
TUNING the Talbot Express 2.0L Petrol Engine |
||
|
Firstly Establish what you are trying to achieve and how realistic this is given the vehicles size, air resistance and weight mentioned above. Remember that
for a coachbuilt even a modest increase in Top-end speed will require quite
a considerable increase in power. Typically anything less than 10% will be
almost unnoticeable on any vehicle, less so on a large and un-aerodynamic
motorhome. However you should expect an "adequate" performance level
(see the forums for other's experiences) and of course you can tune for Fun
:) Please note the following:
So, with out further ado...... 1) Before you start a) Get yourself a set of manuals (the Russek "pocket mechanic" manuals are quite useful, and the official Peugeot J5 Manuals are available on CD (see the for sale section of this website or Ebay). b) Check / Address all usual culprits that result in reduced performance:
2) Having Established that everything is running as well as it can its time to start playing! The engine is an old design that has been detuned from a car engine to focus on Torque over power. This is all basic old school stuff, the most obvious areas being Exhaust Manifold, Exhaust System, air filter, camshaft profile/timing and compression ratio. There is one other area unique to these vehicles and this is the throttle plate and inlet manifold which was enlarged for the face-lift (1991 onwards) models. There is also someone who has fitted a Weber 2v carb to theirs but I can't find details of this at the moment so will add it later. I'll leave the internal engine items (camshaft and Compression Ratio) as these require significant expenditure and a thorough mechanical knowledge. Suffice to say you could compare the TE engine specifications to that of the 1971cc Peugeot 504 for some ideas.
|
||
|
Throttle Body and Inlet Manifold Carburettor Spacer (Phenolic) (Pre-91 Engines) Alternative Twin-Barrel Carburettor
|
||
Air Box / Filter:
Modifying the Existing Air Box (to improve air flow through it)
Fitting an Aftermarked Air Filter (use a good quality one). Consider the following issues:
|
My own modified standard airbox.
Simple aftermarket set
up
(with
thanks to George Hook of preloved) |
|
Remote
located after market set up
(Pictures opposite
courtesy of "Martin" from Preloved. See the "Spacer" discussion topic) |
 |
 |
|
Both the
above aftermarket set ups benefit from must smoother inlet tracks. George's
short stack is the perfect length and would be ideal for petrol or LPG set
up, ideally with a cold air feed directed at it.
Martin's remote air filter has a nice smooth inlet track (plumbing) and benefits from both the cold air intake due to its positioning, and the engine's original "Ram Air" effect due to the choice of filter shape (air being forced into the intake due to forward motion of the vehicle). Positioning the filter in this way does mean it will get very wet so choose a filter (e.g. K&N) that is waterproof. When fitting this I believe Martin did the following:
|
||
.jpg)
|
Throttle Body / Inlet Manifold:
At some point during production (probably the introduction of the Face-Lift models (1991 onwards) the Carburettor throttle plate and inlet manifold were enlarged from 28mm to 34mm which appears to make them faster although the carb internal venturi diameter remained unchanged. You can determine which you have by measuring the distance between the centres of the studs that mount the carburettor to the inlet manifold:
If you can source a 1991 onwards carb and inlet manifold this may be a very easy method of boosting engine performance although it is more expensive than the spacer mod (below). |
|
|
Carburettor Spacer (Phenolic): (Pre 91
Vehicles) With special thanks to George Hook for providing the spacer material for me to experiment with the 1991 vehicle. This modification uses a phenolic spacer between the carb and inlet manifold. It appears to result in a an improvement in performance for those engines with the smaller throttle body giving them a performance increase comparable to that of the later models. I should stress that I have not experienced this myself (having tried it on my 1991 34mm throttled engine) however I respect the feedback of several experienced and mechanically savvy preloved forum members who perceive noticeable gains both in overall power and delivery range using this Spacer on Pre-91 engines. To date :
How does it work ?: The reason for these gains is unclear. It has been suggested that the cooler carburettor helps maintain air density however given that the manifold remains heated (to prevent fuel "drop out") and the considerable volume of air entering the engine at cruise speed of 3000rpm I would have thought this effect was negligible. More research is needed when I get the time! For more information:
|
|
|
Exhaust Manifold:
The standard manifold (shown opposite) is a very poor design for gas flow. Unfortunately there is no after-market 4 into 1 or 4-2-1 manifold available and the space in which to fit it is very restricted. Some people
have experimented with making their own using parts supplied by Birchills
Automotive (http://www.exhaust.uk.net/)
. Details by "JC" below. |
 |
|
The following pictures and write up are reproduced with the kind permission of "JC" (John C) from the Preloved forum. How I did it:
Shown is the
measurements for the manifold flange (check this against your own.) |
|
.JPG){kind=spacer}
|
Images of a 4 into
1 Exhaust manifold complete with flexible coupling to ease fitment and
prevent the manifold stud-snapping stresses associated with the Talbot
exhaust Manifold.
|
 |
|
504 / 505 Exhaust Manifold: You might also like to consider using the Manifold from a Peugeot 504 (shown ) although I've no idea if this will fit, or how the exhaust down pipes could be fabricated to mate this to the existing system. I doubt I'll have time to try this but here are a few pictures that might wet your appetite! Shown
below:
|
|
|
|
|
|
Exhaust System There is no "Upgraded" exhaust system available for these vehicles. The standard system (aftermarket made by Bosal) is a three-piece set up (down pipe, intermediate/front silencer, rear silencer), costing approx £40 per silencer. If performance is particularly bad one might consider whether the baffles might be damaged. Certainly one preloved forum member (B.K. (see "Spacer" thread on the Preloved camper vans forum)) cured a significant lack of power by replacing the front silencer with a straight pipe. BK also uses a downward facing tailpipe dressing piece and does not report any noticeable increase in noise in the cab through removing the middle pipe. Whilst BK's improvements are so dramatic as to suggest a problem with the original exhaust this is a cheap modification that has no apparent downside and therefore worthy of consideration in the quest for more power/torque. If you do try this please post your findings to the "Spacer" thread on the preloved forum or let me know and I'll include them here. Similarly if anyone has pictures of this mod and/or details of any issues that need to be considered/addressed when doing it I'd be happy to include them. |
|
Twin-Barrel Carburettor
Conversion:
|
|
|
Twin-barrel Carb conversion has been done (using a Ford 2V carb) but I don't have any details of how. In theory it should be relatively straight forward ...... The Peugeot 504 (late models) and 505 were both fitted with twin-barrel Solex carbs, however these engines were on a slant (see opposite) so one cannot simply use the inlet manifold and set up from there (assuming you could find any). There was a mechanical fuel injected version of these engines (late 504) and a twin carb (2 single carbs) version but both these are too old and too complex to consider in my opinion (for more info I recommend you purchase the Haynes manuals for the Peugeot 504 and 505) . Note that the electronic Fuel Injection System (Bosch LE-2 K-Jetronic) was only fitted to the overhead Camshaft engines (ZEJ / ZDJ) and not the XN1s. So, what options does that leave us for the XN1 .... Inlet manifold:
Twin-Barrelled Carb:
|
XM engine as fitted in the Peugeot 504 and 505 showing the angle of slant.
|
| If you do decide to try the above then please let me know how you get on (Ideally with some pictures) and I'll post it here for the benefit of others, Thanks | |
|
************************************************************************************** GENERAL ARTICLE ON ENGINE SWAPS (July 2006) ************************************************************************************** Transcript of the Article in Practical MotorHome (July 2006 edition) by “Diamond Dave” their technical guru.
Upgrading the engine in a motorhome is not a job for
the fainthearted. Generally, if you
want more power, the easiest way is to buy another van.
One of the most derided engines in the modern
motorhome world is that of the XN1 overhead-valve petrol unit, as fitted to
the Mk1 Fiat Ducato and Talbot Express ranges. I get a steady trickle of
requests from people wanting to boost performance of these venerable units.
But first things first. I have heard of his engine described as
everything from "hard work" to "pathetic" and in most
cases it's a fault of the maintenance schedule rather than the engine. You don't service the van properly it will
be well down on power and consequently will struggle to perform at his best.
Correctly sorted, the engine should not fluff or
stutter under acceleration it should not judder alarmingly and should go into
gear relatively cleanly. If the engine
is fluffing, all you need to change gear or dipped clutch, but if changing
gear is difficult, the only option is to slip the clutch or just stick with
it. Either way, your trip will be
pretty wearing.
Before you condemn your petrol engine, however
invest a little time and money in making sure it is working properly. Replace the fuel filter and check that the
fuel pump isn't getting worn and shortchanging the engine on fuel.
Worn engine mountings will lead to a tricky
gearchange, which will be impossible to adjust, so check these too. The rear mounting in particular is prone to
getting badly worn, leading to an uncomfortable kangaroo-ing feeling under
load and a characteristically awful gearchange.
If that still does not improve matters, you should
check the exhaust for problems because engine mounting troubles often
manifest themselves as a blowing exhaust , which
will affect your engine running and ultimately the power produced.
If everything is working correctly the number of
engine modifications you can carry out is quite limited. A high-flow air filter kit is affordable
and an easy task for an afternoon, but how much power it will free up is open
to question. If anyone has tried a
K&N filter or something similar, please let me know your findings.
Other than that, you are into the realms of
custom-made exhausts and cylinder head work.
And we have heard of one chap who is experimenting with a
supercharger.
In terms of engine swaps, the conversion to
turbo-diesel looks tempting on paper.
The swap is easy because it was a factory option, but the improvements
are relatively slight. Although the
turbo-diesel has a lot more torque, it's a pretty rough old unit by modern
standards, and the best you can expect is your van to be fractionally quicker
but better at holding its own when overtaking lorries and the like, because
of the extra torque.
In terms of brake horsepower (BHP) the petrol unit
produces 83 while the turbodiesel unit manages 93. The naturally aspirated diesel engine is
less powerful than the petrol version so is not worth consideration, even for
the torque increase.
One conversion worth consideration was developed by
Delfin Designs, near Poole in
The Renault unit fits snugly into the Talbot/Fiat
engine bay, using the existing gearbox and a streamlined gear linkage. It's not a straight nut and bolt conversion
though, so the work has to be carried out by Delfin using its own specially
made bell housing. The power output of the Renault engine is 130 brake horsepower, a conservative 40% plus improvement over the diesel or petrol models but the engine is one overhead camshaft unit, and being all alloy (rather than iron) it's lighter too. At a cost of around £3000 it is not a cheap conversion, but it's a lot cheaper than buying a new van.
**************************************************************************************
|
|
Engine Specs (not sure what year or specific engine types these refer to) |
|||
|
|
|
|
|
|
1.9 Litre
Diesel |
|
2.0 Petrol |
|
|
Capacity |
1905cc |
Capacity |
1971cc |
|
Max Power |
71PS
(51kW) @4600 rpm |
Max Power |
85PS
(62.5kW) @ 4750rpm |
|
Max Torque |
12.5mkg
(122 Nm) @ 2000rpm |
Max Torque |
15.5mkg
(152 Nm) @ 2500rpm |
|
|
|
|
|
|
2.5 L
Diesel |
|
2.5L Turbo
Diesel |
|
|
Capacity |
2500cc |
Capacity |
2500cc |
|
Max Power |
75PS
(54kW) @ 4100rpm |
Max Power |
95PS
(70kW) @3700rpm |
|
Max Torque |
15mkg
(147 Nm) @ 2000 |
Max Torque |
21.4mkg
(210 Nm) @2000rpm |
|
|
|
|
|
|
|
|
|
|