DIY_EFI Digest V4 #530

[Rich Mauruschat]

>DIY_EFI Digest       Friday, September 17 1999       Volume 04 : Number 530
>Date: Fri, 17 Sep 1999 13:41:52 +0200
>From: Nic van der Walt <nvdw at cellpt.co.za>
>Subject: Newbie questions #438-443
>
>Jo
>
>I'm designing the parts I'll have manufactured for my bike's
>EFI manifold and have been wondering about a couple of things.
>Is there a standard form factor for injectors that I can base
>the design on? Can I for example design for a Bosch injector
>and then be able to swap injectors around until I get a type
>that works well? Anyone have any dimensioned drawing they are
>willing to share?

I have a scale drawing of the Bosch pattern (o-ring both ends) injector in
Autocad .dwg format which I produced whilst doing something similar to
yourself. It isn't dimensioned, but I guess I  could add some critical
dimensions and output in a different format if neccessary.

>What is a reasonable minimum on time for an injector? The injector
>will have to flow around 3.5l/h at WOT. How do I go about actually
>buying something? Any brand to look out for? What is a good fuel
>pressure to work at?

If you haven't already, have a look at
http://www.vectorbd.com/peugeot/bosch.html
There is a whole heap of useful links there relating to Bosch stuff,
including lists of injector data (includes other types, Lucas, Nippon etc).

>The bike currently has four carbs. I have been considering using the carbs
>as is, closing of all the ports and mounting the injector basically
opposite
>of where the main jet used to be. This makes the mechanical side of things
>very
>simple and cheap, but places the injector at a right angle to the air flow.
>Will this affect anything?

I think it's generally considered a bad thing to inject across the airflow
path like this, there is a tendency to chuck fuel at the port walls which
then condenses; this is much worse an effect at low speeds obviously. The
Group B Rover Metro 6R4 (V6 quad cam, lots of rpm) used just this
arrangement, that obviously worked OK, produced good power. They were not
concerned about low speed behaviour or fuel consumption or emmissions.
The carbies don't suffer the same problem of course, as the airflow draws
fuel off the main jet in the direction of flow.

>Thanks
>Nic.

hope this helps, let me know on the injector drawing.
Rich M