Re: pfi & 747's

[rr <RRauscher@nni.com>]

Now this is interesting, 30# injectors are rather large for the
power these engines make. Seems as though they are making up
for lack of pw with a larger injector.

The 17ohms makes them saturated, the slow to open type.

Yes, 4-1/4 ohms per bank, 3.2A @ 13.8v, should work. . .

BobR.


Shannen Durphey wrote:

> rr wrote:
> >
> > I wouldn't be too quick to dismiss the '747 for a port
> > injected engine. Edelbrock sells a pfi conversion kit to
> > convert '747 powered trucks over to port.
> >
> > In the tables they change the injector constant to 112, and
> > the pump shot stuff to smaller values. The most interesting is
> > that they leave the injector bias, min bpw, max bpw and the
> > 'switch to async' mode pulse widths the same.
> >
> > The key is to find out if they are using saturated or p&h
> > injectors. Anybody know about this? Other thing in their
> > favor is that these trucks are not revving too high. Although
> > they add fuel fuel right up to the end of the ve table.
> Here's what I have:
>
> > They are 17 ohms DC resistance.  There is no other part number
> > that
> > Edelbrock gives for them except their house number of #3598.  They are
> > pintle-type, they flow 30 lbs./hr at 50 psi, 20 degree spray cone.
>
> Looks like 4 1/4 Ohms/bank of 4, yes?  Compared to around 2 Ohms for
> traditional tbi injectors.
>
> >
> > I'd bet they are using p&h injetors. As the pfi p&h's are
> > twice the impedence as the tbi p&h's, you could drive
> > four from one driver, in a parallel/series configuration.
> >
> > BobR.
> >
> > p.s. still working on an iac writeup, I'm knee-deep in school
> > work, bit more off than I could chew. . . or is that grabbing
> > a hot iron by the end opposite the handle <g>
> Definitely the latter.
> Shannen
> >
> > (Three more Months!)
> >

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