K Series KV6

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:

• Not yet been done
• It shares the same bolt pattern for a Ford Type 9 5 speed gearbox fit as the K4
• Aurally more entertaining with more torque low down compared to the K4
• You could have twin exhaust pipes like a V8
• Your suspension modifications probably limit you to about 160bhp without doing anymore upgrades
• The weight would more closely match the B thus affecting handling less
• The engine is shorter and could sit further back than an-line 4 unit.
• Easier to shoehorn in than a V8 so less metal work, although it is a 90° Vee, so width may be an issue
• To my mind more solid and reliable at this power than the K4 based on my experience of 4yrs/80k miles in my ZT.

Against this of course:

• Heavier than a K4
• It's a tall unit with all the inlet system, although throttle bodies would be interesting
• More fuel to burn than a K4
• It's not been done so you are up against some unforeseen issues

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):

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