injector manifold design

[Stowe, Ted-SEA]

thanks Tom.

with the Bosch LH jetronic even though it has 4 separate injectors, by the
design of the schematic it would appear that they all fire at the same time,
there is not a separate driver for each, just one line out of the box wired
up to all 4.

so at this point, I could use a nice tbi with a single injector, (but I
can't find a nice one),
or simply use the existing injectors I have, or maybe better yet, use 2
larger ones instead of 4, which appeals to me.

so the issue is not really the electronics but the aiming (I think), of the
injectors. I have basically 2 inlet ports on the head where you can almost
see the intake valves.

thanks, Ted Stowe

-----Original Message-----
From: Tom Parker [mailto:tparker at nznet.gen.nz]
Sent: Monday, March 22, 1999 3:58 AM
To: Mike Morrin
Subject: Re: injector manifold design


Mike Morrin <mikem at southern.co.nz> wrote:

>At 08:50 pm 21/03/99 -0800, Stowe, Ted-SEA wrote:
>. outside of the irritating fact
>>that my head has siamesed intake ports, could I create an intake manifold
>>that mimics an injector per port, and have 2, (or one larger one), aimed
at
>>each mgb 'dual' intake port ?

>I think you might have trouble getting mixture balance between the
>cylinders on each port, as they are not 180 degrees firing from each other,
>so how would you time the injection pulses to give each cylinder its fair
>share?

I have thought a little about this, and it shouldn't be difficult to design
a
circuit to take the 4 injector output from an OEM ecm and drive two
injectors
in the correct order. The Mini fires 1-3-4-2, with 1 & 2, 3 & 4 siamesed.
You
would just put the 1 & 2 cyclinder output into a logic OR gate and drive one
injector, and the same for 3 & 4.

The only issue would be overlap between the cyclinders. Is it normal for two
injectors to be firing at the same time in a sequential injection? I have a
feeling that a standard OR gate will switch off if both inputs go high...
there is another gate that I can't quite remember that doesn't

The simplest from an electronics point of view is to mount two injectors,
you
could even aim one at each valve in the port. The trouble is that on a Mini
at
least, The exhaust is right next to the inlet. You would really have to put
one injector above the port and one below, with two fuel rails...

--
Tom Parker - tparker at nznet.gen.nz
           - http://www.geocities.com/MotorCity/Track/8381/