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Engine Upgrades

K/KV6 Series Engines (and N Series)

Firstly, it's probably worth setting the record straight on these engines!  They have a reputation for head gasket failures, perhaps one that has been hyped out of all proportion by the exposure on BBC's Watchdog, and as a result, all Rovers suffer HGF according to the uninformed!  Whilst there are design issues at hand that should have been addressed sooner, or at least culpability accepted, the fact that HGF occurs on many cars is often the result of a problem elsewhere that has not been addressed.  These are alloy engines and the appropriate maintenance and checks of the cooling system are essential as on any other make. 

Subsequently, the Chinese owners of MG, with the aid of the Longbridge engineers have created a Euro 4 compliant K Series knwon as the N Series and as used in n/asp form (135bhp).  SAIC/Ricardo also reverse engineered this and have developed a 160bhp turbo 1.8L TCi-Tec engine to identical dimensions.  These engines are proving to be very reliable although with few of them on the road, there is little chance of acquiring one in a scrap yard.

The K Series is an increasingly more common choice, particularly for the Midget, but also in one or two B's.  Frontline Costello of Bath have specialised in this for the Spridget and offer most parts necessary to convert, but no-one has really specialised in the K Series into the B, presumably because of low demand.   The basic 16v 1.4L offers a similar 103bhp to the older B series unit with half the weight penalty.  This should improve handling being lighter at the front, and the power-to-weight ratio will be far better than a standard MGB. The unit needs to be tilted to fit under the bonnet, and units prior to 2000 will, with the exception of the VVC, have a distributor off the rear of one of the cams, which will mean losing the heater box.  The engine could be mounted further forward to overcome the problem, but the position is largely dictated by the use of the Ford Type 9 box and adaptor kit for this from the likes of Hi-Gear.  The 1.6L offers a little more power up to 120bhp (I stand to be corrected), but the 1.8L offers 120-135bhp and the 1.8L turbo (75/ZT) or VVC offers 160hp, which is of course academic since removing the catalytic converter and factory airbox will improve breathing (I have heard that a 143bhp VVC unit has been on the rolling road producing 157bhp). There are plenty of specialists offering upgrades for the K series, though, which should net some useful gains. You are probably likely to get reasonably low mileage engines for minimum spend with good parts supply longer term. Fuel economy should be good, but as to aural entertainment, you will have to work hard on the exhaust design!

The unit below is the 1.8 K series engine:

Below is the 1.8L Turbo unit but is fairly limited in numbers having only been fitted to the ZT/ZT-T 160 and 75/Tourer.

Below is the VVC unit, the obvious choice if you are looking at a K Series.

And in the flesh...

The above photo is from an article in Enjoying MG (the MGOC magazine - Oct 2003) and shows a 1.8L 120bhp unit fitted to a BGT.  This was a one-off conversion, and although the owner runs a motorcycle engineering business he has no plans to produce a kit, more's the pity.  See detailed photos on the feature car belonging to Mick, as well as following Ed's progress on his VVC conversion.

For more information on the K-series, here are links to other pages with excellent material:

Engine Specifications of interest (Note the brochures show slight variations in figures depending on model and these values are a guide only to indicate potential as it will depend on the fuelling choice and air intake and exhaust design):

Engine Power Torque Fitted in:
1.4L 103Ps @ 6000rpm 127Nm @ 3000rpm Rover 214, 25, MG ZR 105
1.6L 111Ps @ 6000rpm 145Nm @ 3000rpm MG F, TF 115, Rover 216/25, 416/45 and replaced the Honda 1.6 of earlier cars.
1.8L 120Ps @ 5500rpm 160Nm @ 4000rpm Rover 45, 75, MG F, ZR 120, ZS 120 and ZT120
1.8L 136Ps @ 6750rpm 165Nm @ 5000rpm MG TF 135
1.8L Turbo 150Ps @ 5500rpm 215Nm @ 2100rpm Rover 75/Tourer post June 2002
1.8L Turbo 160Ps @ 5500rpm 215Nm @ 2100rpm MG ZT/ZT-T 160 post June 2002
1.8L VVC 145Ps @ 7000rpm 174NM @ 4500rpm MGF and Rover 200 BRM up to 2001
1.8L VVC 160Ps @ 6900rpm 174Nm @ 4700rpm MG TF 160, ZR 160, F Trophy 160 post 2001

Just as an aside, am I the only one thinking that a mid-engined BGT is a possibility?  Take a look at the top photo again!

KV6 Engines

The KV6 first saw use in the 800 series as a 2.5L development of the K4 where it gained something of a poor reputation compared to the earlier Honda 2.7L V6 of previous 800s.  When the 45 was introduced in 1999/2000, the T series was dropped in favour of the 1.8L K or KV6 2.0L the latter only with the auto box option. The power was 150bhp in 2.0L form.  In fact, when MG went racing in the BTCC in 2003, the 2.0L was the engine they used, albeit tweaked and tuned, although it lacked the ability to rev in comparison to the 2.0L K4 that was developed for the BTCC.  The 2.0L KV6 was also offered in the 75 with manual gearbox, but most people felt the 1.8L K4 75 was nearly as quick as the 2.0L KV6 with better fuel economy and less tyre wear as a result of the lighter K4 engine, and this is also the case with the ZT 160 1.8L Turbo compared to the KV6 cars.  In fact, the 2.0L KV6 in the 75 range was eventually dropped in favour of the 1.8L Turbo, as was the 160bhp 2.5L KV6 in the ZT. However the 2.5L KV6 in the Rover 75 is good for around 175bhp, but the 2.5L KV6 also appeared as a 160, 180 and 190bhp set-up in the MG ZS and ZT.  The KV6 also employs a Variable Intake System (VIS) which can adjust the lengths of the inlet tracts to ensure maximum performance and efficiency.

To be honest, this engine in 160bhp 2.5L would be my choice, despite costing a little extra for the following reasons:

Against this of course:

Engine Specifications of interest (Note the brochures show slight variations in figures depending on model and these values are a guide only to indicate potential as it will depend on the fuelling choice and air intake and exhaust design):

Engine Power Torque Fitted in:
2.0L 150Ps @ 6500rpm 185Nm @ 4000rpm Rover 45 Saloon only, Rover 75
2.5L 160Ps @ 6250rpm 230Nm @ 4000rpm MG ZT/ZT-T 160
2.5L 177Ps @ 6500rpm 240Nm @ 4000rpm Rover 75/Tourer, MG ZS 180, ZT/ZT-T 180 with auto
2.5L 190Ps @ 6500rpm 245Nm @ 4000rpm MG ZT/ZT-T 190
2.5L >220bhp   Australian market ZT-220 with Sprintex supercharger.




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