Using TBI on moded 5.7

[Fran and Bud]

Mike,
I cant guess what you may find wrong, but I
wouldn't worry any more about "fuel puddling".
All of my family fleet of TBI's (one Astro, 2 PU's)
puddle as they should.

One of the early 80's SAE papers on TBI 
0098-2571/80/8810/0102 SAE, Inc
included a paragraph on "fuel pulse smoothing" 
and it had the following things to say about 
this area.

Re-phrased snips from paper:

1)  Placement of injectors above the throttle
bores/throttle blades is proper to smooth 
injector pulses over time.

2)  The throttle bore walls and throttle blades 
will accumulate fuel in a sheet that will flow 
toward the openings around the circumference of
the throttle blades. 

3)  At idle and part throttle (MAP less than 
60 kPa) a sonic pressure ratio will exist across 
the blades and this will violently shear off 
the fuel sheet at the openings around the 
circumference of the throttle blades.

4)  This violent mixing of fuel and air promotes
good part throttle distribution and is considered
as a "design feature" of TBI.

Where TBI struggles is when the manifold is 
re-pressurized rapidly (rapid change in throttle
 opening) and a fuel film can/will condense 
on the manifold walls - Part of the reason that
extra fuel (acceleration enrichment) is required 
and why so much of the TBI passages are heated by
hot water.

Bud
        
----------
>From: Mike Vannorsdel <vannorsdel at rmi.net>
>To: gmecm at efi332.eng.ohio-state.edu
>Subject: Re: Using TBI on moded 5.7
>Date: Mon, Nov 8, 1999, 7:01 PM
>

> I can actually see puddling on the throttle plates at idle.