Using a four barrel carb as a throttle body?

[jefferybond]

Hi folks,

I'm currently running a 3.5 rover with an edelbrock 500cfm, along with megasquirt-n-spark to run the ignition. It all runs very well but I love to tinker (hey i'm a chip-designer-geek!), so I'd love to convert it to fuel injection, but on the cheap using the existing megasquirt.

My question: is it possible to use the carb as a throttle body (ie, remove the fuel supply, booster venturis, air flap etc), and modify the 4 barrel manifold to take injectors? Well Im sure it's possible but has anyone done it? Clearance looks tricky to fit 8 injectors, so maybe fit 4 injectors directly under the carb?

Obviously I'd need a high pressure pump, regulator, fuel return, swirl pot etc to run it all!

Cheers,
Jeff

[kiwicar]

It all can be done but it woul be simpler to use a throttle plate designed for the job, I am pretty sure Elliot uses one and I think either Bill Shuvinton or Phill Ringwood sells them. From what you get for selling the carb you probably won't be much out of pocket. Putting the four injectors into the plenum will be OK but won't be as good for mixture distribution.
Mike

[HairbearTE]

That probably has been done but the availability of good 4bbl throttle bodies at sensible prices means it is not really neccessary. Most of these will also include useful features such as a throttle position sensor etc. Also bear in mind that you can use a throttle body of much greater cfm than that of the appropriate carb for most engines. The two main reasons for this is because the venturi effect is not required to atomise the fuel and of course also the controlling of the fueling by an ecu.

[CastleMGBV8]

Jeff,

Seems a lot of bother for what will be an inferior set up when you can puck up a hotwire manifold trumpet base and plenum including injectors for a £100 or less.

I got a gems system set up for £70 from Alan Coote at Range Rover Heaven but the gems plenum is too high at the front so will need a 3.9/4,2 version to fit under my MG RV8 bonnet.

Give him a call 07711 369785

Kevin

[Eliot]

Yes it can be done:
http://www.mez.co.uk/ms2.html

But this was in the early days, before these were readily available:
http://www.mez.co.uk/turbo9.html

Either way you will need to convert the manifold for injection:
http://www.mez.co.uk/ms4.html

But as others say, for a rover your best bet is the fit the std plenum and trumpets - as it has everything you need and works well.

[jefferybond]

But this was in the early days, before these were readily available:
http://www.mez.co.uk/turbo9.html

Hmm, they look nice. How much do the autonomics throttle bodies go for? Do they come complete with injectors and fuel rail?

Not keen on using stock EFI parts because I want to keep my Hilborn scoop!

Jeff

[Eliot]

Search for Bill Shurvinton on this board, he may have some in stock.

[kev_the_mole]

How much do the autonomics throttle bodies go for? Do they come complete with injectors and fuel rail?

Can't give you prices but Bill does supply both injectors and fuel rails as I've just bought a set.