Gee, I guess all that work we did on stacks for the Hilborn Fuel Injection for
the
Offy & SBC doesn't mean anything.......;-).....
Mark Haynes wrote:
> Craig et al,
> David Vizard did a fairly complete study on velocity stacks, as printed in
> "Building BMC 'A'
> Series Motors" and the upshot of his flow bench work was that the radius at
>the
> end is the greatest determining factor in flow rates, not the length of the
>velo
> stack. tThe length lends itself directly to the intake path length, which
> affects the power at RPM only, NOT throughput (flow rate) . Per this treatise,
> if your cam gives more horses at a higher RPM, you want a longer intake path,
> and vice-versa.
> Just my condensation. My .02?- go with a velo stack that fits without
>major
> modification, and is as close as possible to your expected HP profile-You
>could
> Dyno it of course.
> Mark Haynes
>
> Kerry Seibert wrote:
>
> > GREG - try APT (Advanced Performance Technology) in Riverside, CA.
> > www.aptfast.com They have all kinds of goodies that might help. I'm
> > using their SU billet stub stacks on my 1 3/4" SUs and a K&N filter fits
> > over the stack. Still fits under the bonnet of my Morgan.
> >
> > Craig Seibert 1968 Morgan +8 car no. 611 "Duff Morgan Racing"
> >
> > PS I've talked to a few people who say the "tall" velocity stacks (though
> > they certainly look cool) are not as good as a good "stubby" stack as far as
> > air flow and turbulence. APT seems to be one of them. I'm no expert nor
> > engineer . .. . . . . just using what seems to work for me . . . . . .
> >
> > -----Original Message-----
> > From: owner-vintage-race@autox.team.net
> > [mailto:owner-vintage-race@autox.team.net]On Behalf Of
> > Gregory_Schulz@mil-elect-tool.com
> > Sent: Monday, May 22, 2000 4:13 PM
> > To: vintage-race@autox.team.net
> > Subject: Filters for velocity stacks
> >
> > A friend runs vel. stacks on twin SU's.
> > He has round cylindrical "slip on" foam
> > filters about 4 in. OD and approx. 6 in.
> > in length. They are very low restriction
> > but do manage to keep sand, stones, etc.
> > out of the internals.
> >
> > It is of "one piece" construction, versus
> > several pieces glued together. The filter
> > shape is reinforced by large internal coil
> > springs which capture the lip of the stack
> > and holds the filter in position.
> >
> > They were on an ex-SCCA Sprite from Texas,
> > I believe, and over time the source info
> > has been lost.
> >
> > Does anyone know if something like this is
> > still available somewhere?
> >
> > Thanks,
> > Greg
> > VSCDA #517 Sprite
> > Cedarburg, WI
--
Art Blackwell
Denver, CO
" Even in the future nothing works " Dark Helmet " Spaceballs "
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