Partial success - final take

[Walter Sherwin]

Yes, the small areas between the TBI throttle blade edges and the bore walls
play a HUGE role in fuel atomization in TBI setups.   The small areas
promote extremely high localized air velocities at anything less than WOT,
and associated vortices below the blade(s),  which promotes vigorous mixing
downstream within the plenum(s).  Also, the sharp machined edges are
intentionally left in place to promote further promote shear of the liquid
fuel.

Your TBI injectors will have a somewhat wide spray angle (70 degrees?),
originally intended to spray the fuel charge "into" the small annular
openings between the blade(s) and the walls, while intentionally missing the
blade during its fullest arc.  In the absence of a throttle blade  (ie: you
remove it), the fuel spray from the TBI injectors will simply splat against
the bores, drip down, and then ??possibly?? re-entrain with the airflow to
some degree within the bowels of your wet manifold.

If wanting to attempt a bladeless quasi-TBI blow-thru fuel delivery
mechanism for a wet manifold & dry S/C application, then perhaps think about
installing PFI injectors in place of the TBI injectors downstream of the
S/C.  This will take a fair bit of custom machining, and a fair bit of
research, as there are many different "plumes" available with individual
PFI's.  Cone angles tend to range from 60-12 degrees, and the patterns can
be anything from hollow-conical to pencil stream.

What you have proposed is not new, but needs a fair bit of research to work
right.  Ideally, true port fuel injection is the best way to go in
conjunction with the throttle upstream of the S/C.


Walt.





> Now does anyone know, if removing the throttle blade out of the tbi will
> have any effect on the delivery of fuel in the tbi, is the shear of the
> throttle blade used for fuel vaporization in these systems ?
>
> Dan  dzorde at erggroup.com


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