CLASSICS WITH MODERN ENGINES
LOTUS ELAN PLUS 2
Could this be sacrilege? Colin Chapman's designs are viewed by some as unbeatable, and Chapman himself is a god in many enthusiasts' eyes. But Mick Stott, aided and abetted by long time Lotus specialists Spyder Engineering, has thrown out the original twin-cam engine and four-speed gearbox, and revised the original suspension.
It's best if we let Mick explain why he's moved away from Chapman's design to fit a modern Ford Zetec engine. A couple of years ago i was looking for something that i could get two adults and two children into, so the Plus 2 came to mind. But it had to be something that i could use for track day's, or just jump in and drive to the coast with family.
'A friend of mine had a Banks Europa [a re-engined version of the classic mid-engined Lotus]. Then i got speaking to Andy Widnall at Spyder in Peterborough (01733 203986) and he said they had been playing around with the Zetec and five-speed box in one of their replacement chassis. It sounded like just what i was after. To rebuild the Lotus engine isn't cheap, and i wasn't going to get the performance or reliability out of it that i wanted without spending a lot of money.
So that's the theory. The practice starts with Spyder's chassis, which is a spaceframe version of the original sheetmetal backbone chassis. Spyder has been producing these for over 20 years, but found that it needed only slight modification to fit the double-overhead camshaft, 16 valve Zetec engine that Ford has used in the Mondeo, Escort and Focus, among others. Of course, the Elan's original engine is also a double overhead camshaft unit, based on Ford's pre-crossflow engine block, as used in the Cortina, so there are historical links.
Just as importantly, the chassis could also be tweaked for a five-speed gearbox (whether or not a modern engine was fitted), something owners have been screaming for almost since the Elan's launch in 1963 (Lotus reacted with the Plus 2S 130/5, but had to resort to an awkward Austin Maxi-based gearbox, and only a handful were built).
So that's where Mick started, and the result is a conversion that sits neatly in his 1970 Plus 2's engine bay. Fire, and it sounds spot-on. Any Lotus engine's soundtrack is dominated by the greedy gobbling of the twin side draught carbs - Mick has ditched the Zetec's original fuel injection, for simplicity and for extra power, in place of fully-mappable modern fuel injection by MBE. The resultant throttle bodies and air filter make just the right noises. The idle is a tiny bit uneven, too, just like the real thing, thanks to piper fast road camshafts, and the rest of the noise comes from a lovely looking exhaust system that Mick fabricated himself. He's made a great job of it, But future Zetec converters will be able to buy a similar set-up off-the-shelf from Spyder.
With a gas-flowed cylinder head and careful engine mapping, the 2-litre Zetec in Mick's Lotus produces 200bhp. When you consider that his car would originally have produced 118bhp, and yet still have had a 0-60mph of 8.9 seconds and a top speed of 118mph, you can probably appreciate how quick Mick's car is. And that five-speed gearbox, an MT75 unit, really shows its worth on the motorway, when 70mph finally becomes the relatively quiet, relaxed cruise that most of us crave at least every now and again. Fuel consumption of 40mpg is possible, thanks to the modern injection and ignition. The conversion goes further than the engine and gearbox too, because the Spyder chassis can take either Lotus suspension and hubs, or Ford Sierra hubs and matching brakes, with the original Chapman strut spring and damper units replaced by modern Spax adjustable coilovers. That not only uprates the brakes, it also eliminates the wear that will typically be found in the struts and hubs.
Practical Classics August 2001