You might have heard that Caterham has found a new engine supplier in Horse (decent name, I think), a joint venture between Renault and Geely.

Horse engines will go into Caterham’s Academy racing cars (which I have driven) from next year to replace the Ford 1.6-litre Sigma engine, which Ford hasn’t made in years. Caterham has been assembling race car engines from a stock of blocks and bought-in parts and stopped using it in road cars some time ago.

The Sigma is a nice engine. Autocar had one in a 140bhp Supersport long-termer that we ran in 2012-13, and I spent a lot of time in it, including an edifying day at Rye House kart circuit to see whether any car could have the handling of a go-kart. The answer was no, of course, but still, I remember it as one of the best driving days of my life.

The Sigma is lighter than the Ford 2.0-litre Duratec engine (which Ford doesn’t make any more either) that Caterham now uses in most of its road cars, and it has considerably more power than the kei car-compliant 660cc Suzuki-engined 170. But with the arrival of the Horse engine, the Sigma is finally on its way out.

To mark its run-out, Caterham has announced a special-edition road car, the 310 Encore. The engine is tweaked to 152bhp at 7000rpm, plus you get a lightened flywheel and sports suspension. There are some other upgrades too, there will only be 25 of them and they will cost £39,995.

Of late I’ve said that my favourite Sevens are the 170 and the 620, the extremes at either end of the scale, but this Encore car might just sit in a sweet spot reminiscent of that old Supersport.

If you’re looking for a Goldilocks Seven, this could be it.