Fantasy Engine

[Bill]

As well as my motorhome I own an ancient (E-reg) Citroen BX diesel. Although it was made before the Peugeot-Citroen merger the engine is in fact a Peugeot XUD. It is 1905cc and develops 65bhp, giving the BX a top speed of 99mph. The turbo version develops 100bhp and has a top speed of 120mph.

 

This engine hasn’t missed a beat in 250,000 miles and has had only routine servicing. Part of that is to replace the cam belt every 50,000 miles, which costs £50. A friend has a VW Golf diesel, which is also 1900cc and also needs its cam belt replaced every 50,000 miles - but that costs £500.

 

Although the XUD is just a plain old-fashioned diesel – no common rail, high-pressure injectors or fancy electronics – it is silky smooth: the diesel BX is smoother and quieter than the petrol BX.

 

Fuel economy is quite literally incredible. When I first had it I was getting about 45mpg, which is reasonable but not exceptional. Then a friend who is an HGV instructor gave me some tips on “torque-curve driving” to which I added some techniques used for handling complex aircraft engines (“complex” means fitted with a constant-speed propeller), and the fuel consumption went to 75mpg.

 

At first I didn’t believe it, and thought there must be something wrong with the odometer, so on several long trips I checked the odometer against the mileposts. They agreed exactly. That figure of 75mpg is an average over 150,000 miles.

 

 

It would be the perfect motorhome engine except that 65bhp just isn’t enough.

 

So, my Fantasy Engine: put two XUDs together on a common crankshaft to make a V8. That would give 3.8 litres and 130bhp - just about the same as the 127bhp of the near-ubiquitous Fiat JTD. And if you were really in a hurry you could put a turbo on it and get 200bhp.

 

I really think PSA missed a trick here.

 

 

[Clive]

Er, what about the additional weight and windage of the motorhome compared to your car?

I expect it wouldn,t do as well as a modern common rail diesel.

 

But I like the idea of the V8 3.8 litre, sounds about right for grunt.

 

[fred grant]

fred is starting a torque curve driving school. first one in redruth.

 

bookings taken now, and please dont rush all at once as it cood take a long time for denzil (our instructor) to get up to sppeeed. he aint passed is ordinary driving test yet.

 

backtofightingfitfred

[DirtyHarry]

I love the thinking, but by bolting on the extra engine to make the V8, you'd lose 75mpg and get.. what...37.5mpg?!!

 

Tell me more about this Torque driving though, i'm all ears.

 

 

8-)

[tonyishuk]

Rather taken with the VW idea of 1400cc engine with a super charger at one end and a turbocharger at the other. (Not on a M/home tho')

[Derek Uzzell]

Bill: I'm perplexed by your comment about a £500 cam-belt change on a 1.9litre diesel VW Golf. I've got one of these - a 1995 TDI Estate. When I checked the 2003 service record that included a cam-belt replacement, the price of the belt itself was £17 + VAT and the cost of supplying and fitting it was £56 + VAT. That's £86 overall, which I think is pretty good considering what a sod it can be to change belts sometimes.