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MG ZR ZS ZT Technical - MG Diesels

I see that MGR are now offering their 2 litre 100HP
Diesels.Is that the same noisy engine that existed in
the Rover 45 ? Does anyone have recent experience of owning/driving such a vehicle ?
tony

FWIW: Popped into my local Jet-Wash yesterday (to clean an engine compartment prior to working on it). Guy in the next jet-wash bay had a new Rover 75 which was covered completely in soap suds. I asked him how he liked the KV6 and he corrected me as his car was in fact the diesel version. His car was a month old in that nice Zircon Blue like silver metallic - which really suits the R75. He told me that he was delighted with the car from all aspects. His previous car was a BMW ... another small victory for MG-R ... good eh?

As his car drove away, I could not tell it was a diesel. Really looked the business ... these R75s and their MG Zed equivalents really look the business. Punters seem to like them too!

JMcF.
John McFeely

Thanks John,but I wonder if the 75 is using the same diesel as in the 45 and 25 ?
tony

Thing is that 1o0 bhp is really out of it nowadays. Everyone is developing more power than that now, and the ZS is hardly a small car. VW have had 110 bhp for a long time, and now have 130 and 150 brake engines.
Michael Watkins

yes Mike,this worries me too,as even Renault now have a 150 HP diesel.
However,if the new benchmark for diesels is to be 150 HP,this would equate to over 200 HP in
petrol engines for similar overtaking performance-which means MGR don't yet have a single
product on offer !!
tony

I think the forecoming ZT CDTi diesel has the BMW M47 common rail unit lifted straight from the R75 diesel, which is 114 bhp, and about 191 ft/lbs of torque.

However I can't find any firm info on the spec as yet, I'm interested as when my current KV6 engined R75 comes up for renewal later this year, I'd seriously consider a ZT CDTi if it has sufficient poke. I would hope that both power and torque outputs are up on the R75 unit, as 114 bhp in a car the weight of the R75 is not that exciting. The emmissions tax on the KV6 engines is horrendous, so diesel power is important.

I think the ZS will have the L series unit which is not common rail, and is now well off the pace compared to what VW, Ford, Renault and many others now offer.
Adrian

Tony,
You say the new petrol engined benchmark is becoming 200 HP in which case,despite all the shouting,
MGR don't have one single product to offer until the new V8s are introduced !
alex

It seems the 260 HP V8 car will be exhibited at the Paris Show end September;
Wonder if the newly announced engines will be there too,or are they reserved for the
Birmingham venue ?
andrew k

Recieved info. today from my MGR dealer on the new ZT CDTi diesel. Engine choice will be the current R75 BMW sourced M47 4 cyl. common rail engine, with power and torque unchanged from current R75 specs. Also on offer will be an uprated version of the same R75 M47 engine with 131 PS (but no torque figues available as yet). Presumably this increase is achieved by re-mapping the engine management system, or "tweaking" the turbo??

Other specs and options are the same as for current ZT / ZTT 160 & 190 petrol KV6 models. Dealer says that he'll have a ZT CDTi demonstrator later this month and I've booked a test drive.

Latest R75 brochure states that the new 1.8 turbo K series replaces the 2.0 KV6. Engine choice for R75 now 1.8 K series (normally aspirated), 1.8 K series turbo, 2.5 KV6, and 2.0 CDTi in both 116PS and 131PS versions.

As far as I'm aware the only vehicle to use the 1.8 K series turbo unit is currently the R75
Adrian

Is this the same diesel engine as fitted in my ZR?
I'm wondering if the engine uprating would be an option? I saw in Autoexpress that MGR are going to offer a retrospective uprating to R75 owners, so maybe an option for the ZR as well?

Cheers
Andy
VE02 RHO
Andy

Andy,

No - your ZR has the L Series TD engine which I believe is in the process of being transferred from Land Rover's Solihull plant to MGR Powertrain. Its a totally different unit to the M47 engine fitted to the R75 / ZT. However now the L series is being produced "in-house" by MGR Powertrain, hopefully we will see some product development.
I'm not aware of any retrospective upgrade packages for the L series offered by MGR, but maybe there are
specialists out there who can offer this ??

Adrian

The M47 16 valve BMW diesel provides 116PS and 260Nm torque. The official 499 pound upgrade to 'registered cars' (i.e. it is not a production line fit to avoid needs for type approval changes) raises this to 131PS and 300Nm torque. This upgrade is the 'first' from MGR which will include the L series diesel later. Other companies such as JE Engineering in Coventry can already provide upgrades for the L series. Usually this it to raise from 101PS to around 125Ps with a 25 or so Nm increase in torque.

L series diesel production was shifted from Longbridge to Land Rover by BMW, it is now back at Longbridge as Ford (Land Rover) do not have a long term future for this engine. Clearly the L series is competitive in torque and the performance it gives in the ZR and ZS, but outright power is not competitive. Buying and relocating the engine is not a small job and if this is for just the short term life of ZR, ZS and a few Land Rovers until they change to a Ford sourced engine, then you would have to question the wisdom of such a move.

However, moving the engine into the 'fold' creates many opportunities not available when you are a customer for someone elses engines. In house costing making the engines cheaper is one aspect and then there is the freedom to develop the engines to be better suited to your products. I have seen how JE have made a race L series with over 150bhp so in power terms it is well within sight. However even the VW engines suffer from the law of diminishing returns in that the fuel needed to create the power sees a larger drop off in the fuel efficiency areas.

The L series is essentially based on the O series engine family and of course the O series spawner the 16 valve M and T Series petrol engines. The 2 litre T series last seeing service in the last Rover 420 and the 820 at the end of the last decade. If follows in my train of thought that having bought back the L series it makes sense to look at developing it further. O series petrol had an issue with the heron head design and the resulting combustion qualities. This was dealt with by the 16 valve heads of M and T. Adopting the same principles through a modified T head design could then provide an engine that could also remove the need to buy in the BMW M47 engine.

Add to this common rail fuel management (the L is already direct injection) and there is certainly the on paper potential for a cracking engine. Certianly when looking at the bottom end of any O series family engine L included there is huge reserves of strength.

So the aquistition of L series could in the long term be a real winner, at least I would hope it is. In the short term I expect that the post registration modifications will become available for the L and push this to circa 120bhp and 165/170Nm torque. (My guesstimates) I feel such a kit will almost certainly become a fit on a large proportion of ZR and ZSels sold.

Another aspect many miss is the gearboxes. The 75/ZT uses a Getrag box whose nominal peak torque capacity is quoted at 260Nm, yet the kit now marketted achieves 300Nm. Clearly 300Nm is regarded as an acceptable level for long term use.

The PG1 gearbox comes in two flavours 215Nm and 240Nm. The ZS180 and Diesel ZR and ZS all produce a maximum of 240Nm. If, as I expect, diesel kits arrive that raises the torque 25 to 30Nm above the limit, this also opens the door for a more powerful V6 tune too, or a high pressure turbo 1.8. Interesting opportunities I feel.

Rog
Roger Parker

This thread was discussed between 01/09/2002 and 07/09/2002

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