DIY_EFI Digest V5 #5:re MGB manifold

[Carter Shore]

I have a similar problem, siamesed intake ports on my
Spitfire. I am going to use 4 injectors installed on
the stock manifold. I will mill 4 holes, at very
shallow angles, two on each tube, as close to the head
mating surface as possible. The holes will be
'splayed' when viewed from the top, such that each
injector will fire accross the centerline of the tube
and into the intake port on the opposite side. The
exact angles and position are chosen to hit as much of
the intake valve and pocket, and avoid as much of the
manifold and port walls as possible (it helped to have
an extra cylinder head to work with). I will fit
thinwall steel tubes into these holes (press fit if I
can, JB Weld if too loose), and trim the inside flush
with the manifold walls. This to provide a mounting
boss and a smooth and consistent sealing surface for
the lower injector O-rings. Splayed mounting requires
fuel supply via individual fittings. I'm thinking of
using brass T fittings (from brake systems), center
hole reamed to fit upper O-ring, connected with
aeroquip hoses or flared steel tubing.

When retro-fitting injectors, we cannot always mount
the them as closely to the valve pocket as we need.
Thus, a narrow spray pattern may be preferred, to keep
from wetting the walls.

One thing that I have not seen on any of the lists is
the characterization of spray patterns for different
injectors. Everything is oriented towards flow rates,
and impedance. The archive article on building an
injector flow bench addresses inspection of the spray
patterns, but I have not seen any info that would
allow you to determine what pattern an injector has
from it's part number or application. 

Surely that information is available somewhere?

Just my .02, good luck with your project!

Carter Shore

.....
> there was some issue.  I would like to find a method
> to 'add' 2 injectors to
> an existing aluminium, or maybe a cast iron intake.
> I don't see much around
> for this, but I may be looking in the wrong place.
> I'd rather not have a
> fuel rail as the mounting sort of precludes that.
> 
> the mgb has a siaimesed intake design. 
> 

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