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How to fit fuel injection with no-one knowing

How to fit fuel injection with no-one knowing Classic and Performance Car

Need your classic to start every turn of the key, offer peak performance reliably and and look period correct while you’re at it? There's now a way to fit fuel injection without ruining your classic’s look


We love carburettors. These passive, air-sucking, petrol-vaporising devices are central to the classic-car vibe, an amalgam of approximations able to feed our cars’ appetites with just enough petrol left over to wash away the flat spots and perhaps leave an olfactory trace of heady hydrocarbons. 
 
No carmaker uses carburettors any more. Everything is injected nowadays, road cars for fuel efficiency and cleanliness, competition cars because perfectly managed injection and ignition mean maximum power potential.
 
Should we fit our classics with fuel injection, then? Instant starting after being left for weeks, less fuel thirst, less trouble passing emissions tests should your car be subject to them… it does sounds tempting.
 
There are aftermarket fuel injection systems that bolt straight to a Weber DCOE/Dell’Orto DHLA manifold. The carburettors are replaced by simple throttle bodies, which incorporate injectors. But they look a bit modern, not what you want to see under the bonnet of your 1960s Aston Martin, Lotus Elan or Alfa Giulia.
 
One of the most prolific makers of modern throttle-body systems is Jenvey Dynamics. It spotted a gap in the market, now obvious to anyone who has read this far, and came up with the Jenvey Heritage Throttle Body. It looks for all the world like a twin-choke sidedraught Weber DCOE but is actually a pair of throttle bodies.
 
Look more closely and there are differences between the Weber and the Jenvey HTB, of course. It’s imitation as flattery, rather than copying. The bump above what was originally the float chamber is missing, and the sloping bulges from the chamber to the manifold face are very un-Weber. They contain the Bosch injectors, fed by a fuel rail in the ‘float chamber’ lid and squirting into the inlet ports on the engine side of throttle plates set further away from the manifold face. 
 
Original-equipment air filters and throttle linkages will fit the HTBs, but you’ll also need an engine management system to drive the HTBs and provide the sparks – from DTA, Megasquirt, Omex or similar – and a setting-up session on a rolling road. The result should be a classic engine running as cleanly and reliably as it can while looking proper. More powerfully and with a better torque spread, too. Sounds good to us, especially as SU-lookalike versions are also planned.

Alfa Romeo Giulia Classifieds

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Evo, the world’s premier performance car magazine. Try 5 issues of evo today for just £5 and receive a free welcome gift!