buick-rover-v8
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Re: 3.5 V8 manifold

To: "Jones, Daniel C" <Daniel.Jones@MW.Boeing.com>
Subject: Re: 3.5 V8 manifold
From: Jim Stuart <jimbb88@erols.com>
Date: Thu, 12 Aug 1999 18:02:16 -0400
Well, we finally found someone who knows Holley carbs, thanks, Dan, for all the
info. I will be saving this one.

The simplest carb around would be the Carter 9510, since the 9410 is long out of
production. They show up occasionally, but are expensive, & will probably need a
rebuild. At least on a conventional gasoline powered 3.5 or 215, the 500 cfm
Carters work fine out of the box, with only minor mixture & idle adjustments, I
also have know info on LPG.

Have you tried contacting RPI Engineering in England? They offer conversions to
LPG, parts, etc. Web site is < rpi-engineering.co.uk  > .  Check it out, send
them an E-mail.


Jim Stuart

"Jones, Daniel C" wrote:

> >My brother in law is fitting a 4bbl Holley to his Land Rover Stage 1 V8.
> The engine is the
> >standard 3.5L carb model.  Does anyone have any  suggestions on the best
> inlet manifold to use?
> >It would be good if its available in Aust.  I can't remember if the holley
> is a 350 or 450 - does
> >anyone have ideas on what the best one would be.  It will make his day if
> all the suggestions are
> >different to what he is getting!!!!  The Land Rover is used a lot in off
> road driving, as well as the >usual blacktop travelling.  The truck also
> runs on LPG if that makes any difference.
>
> First off, check the carb document I've been working on for the Pantera
> club.  So far it consists of comparison and sizing sections and I'm working
> on tuning and troubleshooting sections which will be added later.  I'll also
> add a table of contents at the next update.  Anyway, the document can be
> found at:
>
> http://www.panteraclub.com/docs/carb.doc
>
> Be aware that you'll need Word to open the document.  It was saved as a Word
> 97 document but next time I'll save it as HTML so it can be directly opened
> by a browser.
>
> The Land Rover is a relatively heavy vehicle for a 3.5L V8, so concentrate
> on a carb and intake manifold combination that works well at low RPM.  Stay
> away from the single plane intakes (Offy Equa-Flow 360, Huffaker, Harcourt,
> Wilpower).  The factory Buick/Olds 215 4 bbl, Offy Dual Port, and Edelbrock
> Performer Rover are the intakes you'll want to consider.   The Dual Port is
> probably the best of these for low RPM torque and fuel economy.
>
> The small Holley 4 barrel carbs are the 390 and the 450.  The 350 and 500
> are 2 barrel carbs.  Of these, the Holley 390 is your best bet.  Be aware
> that Holley makes at least 3 different 390's.  List number 80507 is meant
> for carb-restricted racing applications, list number 6299 is meant for 4 and
> 6 cylinder applications, and list number 8007 is meant for small
> displacement V8's.  The list number for most is stamped into the upper right
> hand corner of the airhorn (a.k.a. the choke tower).  On models without a
> choke tower, the list number is stamped into the main body behind the
> throttle linkage.
>
> The 8007 is a 4160 Holley which means it has a plate with fixed size
> orifices for metering.  These plates are replaceable but cost much more than
> jets.  If you plan on doing any tuning (and you should), you'll want to
> convert to the 4150 secondary metering block which has removable jets.  The
> 8007 also comes with a 6.5 power valve which you'll need to replace to match
> your engine's vacuum characteristics.  Check the vacuum at idle (warmed up
> and in gear if the vehicle is equipped with an automatic transmission) and
> at various *steady* cruise speeds.  The power valve should be picked to open
> at 1 1/2" to 2" Hg below the minimum steady vacuum reading.  For instance,
> if 11" Hg is the minimum observed, pick a #90 power valve (trips at 9.0"
> Hg).  Note that the power valve only determines when the additional fuel is
> added.  The amount of fuel added is determined by the diameter of the power
> valve channel restrictors (PVCR's).  To properly tune the power valve
> circuit to provide best power and best fuel economy, the PVCR diameters will
> probably need to be altered.  Unfortunately, this means making permanent
> modifications to the metering block, either drilling the passages larger or
> epoxing them shut and re-drilling smaller. Ben Zwissler is running around
> with a Holley 390 re-worked by Ted Schumacher's Holley guru.  He may have
> more info but I believe they found the PVCR's to be too small.  Add the
> power valve protection kit while the carb is apart.
>
> You'll also probably need to change the vacuum diaphragm spring which
> controls the opening rate of a secondaries.  Holley makes a spring
> assortment kit (P/N 20-13) for tuning purposes.  The color-coded springs run
> from light tension to heavy:
>
>         White - Weakest
>         Yellow (Short Spring)
>         Yellow
>         Purple
>         Plain (Steel grey)
>         Brown
>         Black - Stiffest
>
> A lighter spring will allow the secondary throttle plates to open more
> quickly.  Likewise, a stiffer spring will delay the secondary opening.  To
> make spring changes easy, Holley makes an inexpensive quick change kit (P/N
> 20-59).  It consists of a two-piece secondary diaphragm housing cover which
> allows spring replacement without housing disassembly.
>
> Unfortunately, the Holley is not a particularly good carb off-road.  To make
> a Holley perform satisfactorily off-road, a fuel bowl conversion (p/n 34-3)
> may be required.  This kit which fits 4150 and 4500 models only, and
> includes a spring-loaded needle-and-seat assembly (available separately
> under p/n 18BP-268AS) and a spring-loaded float.  Also recommended are
> baffles and vent tube extensions.
>
> As an alternative to the Holley 390, you might want to consider a Carter or
> Edelbrock AFB.  With it's small primaries (see table below), the Carter 9400
> or 9410 (400 CFM models) would be particularly well suited to your
> application but they are no longer produced.  However, D&D in the States
> usually keeps rebuilt models in stock.  Due to their fuel bowl and float
> arrangement, Rochester and Carter carbs have the reputation of being better
> off-road carbs than Holleys.  The spread bore Thermo Quads and Quadrajets
> have particularly good reputations but they would require an adapter plate
> to mount to any of the commonly available Rover/Buick intakes.  Check my
> carb page for details.
>
> I don't know how LPG would affect all this, since I never messed with the
> stuff.
>
> Dan Jones


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