[Diy_efi] injecting 5 port head

[Carter Shore]

I face a similar situation with 1147 Spitfire motors,
siamesed intake ports.

Here's my plan of attack:

1) Use 4 injectors, in sequential order, synchronized
to crank TDC, and a camshaft sensor.
2) Choose injectors that have a narrow spray angle.
3) Choose the injector flow such that max fuel
requirements for a single cylinder requires < 50% duty
cycle. 
4) Orient spray away from adjacent cylinder.

Item 4 means that the injection axes will probably not
be parallel, which complicates the plumbing somewhat;
i.e. indiviual fuel hoses to each injector rather than
a common rail.

Item 3 means that minimum pulsewidth at idle may be an
issue, so P&H injectors are probably needed.

The injection scheduling algorithm may require
variable timing with respect to RPM and/or throttle
position to compensate for unequal airflow split.

Carter Shore


--- Jean Belanger <jean at jeanbelanger.net> wrote:

> Phil,
> 
> There's been quite a few discussions on that subject
> on the Megasquirt forum
> and the TurboMinis.co.uk forum. Marcel Chichak's web
> site
> (http://www.planet.eon.net/~chichm/efi/siamese.htm)
> goes into the details of
> the problem of injecting the A-series engine and his
> own failed attempt
> (http://www.planet.eon.net/~chichm/efi/efi.htm). You
> can also have a look at
> Rover's patent for the MPi Mini which shows how they
> went about implementing
> port fuel injection for the A-series engine.
> 
> I am currently modifying the MS2 code to support the
> needs of the siamese
> port injection. I should have a first alpha version
> before the end of the
> year. If you're interested go to the
> TurboMinis.co.uk forum where I'll be
> making the announcement when the code is ready.
> 
> Regards,
> Jean
> 

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