[DeTomaso] Predator Carb

[John Taphorn]

Dan

Thorough as always.  Thanks for taking the time to provide an overview.

J, wishes he had a Holley Strip Dominator, T


----- Original Message ----- 
From: "Daniel C Jones" <daniel.c.jones2 at gmail.com>
To: "Pantera REALBIG forum" <detomaso at realbig.com>
Sent: Wednesday, November 17, 2010 10:40 AM
Subject: Re: [DeTomaso] Predator Carb


> The Predator is a constant vacuum, variable venturi, design and uses a 
> pair
> of spring loaded air valve doors on top and a pair of throttle plates on 
> the
> bottom to form a single, variable-area venturi that is rectangular in
> cross-section.  Depending upon air flow requirements, Predators will flow
> between 600 to 930 CFM at wide open throttle.  Tuning the Predator is very
> simple, as there are only three basic adjustments: idle mixture, idle 
> speed,
> and fuel metering cam.  The metering cam, located inside the fuel bowl, is 
> a
> flat piece of brass that is cut to a certain slope.  The particular slope 
> of
> the cam is determines the air/fuel ratio from roughly 3000 RPM and up.
> Note that certain race versions of the carb have no idle adjustment.
>
> The Predator is designed to bolt onto standard 4 barrel intake manifolds
> and uses a base plate with fastener slots that allow it to bolt onto both
> squarebore and spreadbore manifold flanges.  It comes with an adapter that
> allows a standard 5" base air cleaner to be fitted and measures 5 1/4" in
> height, from the bottom of the base to the rim of the air cleaner adapter.
> Since there are no vacuum hose connections on the Predator, vacuum will
> have to sourced from manifold or carb spacer ports.  On a naturally 
> aspirated
> motor, 6 PSI at wide open throttle is required for maximum performance.
>
> Vizard reports that Predators will usually deliver good fuel economy and
> excellent street driveability, though they will sometimes not produce the
> expected top end.  This is probably due to the fact that the manifolds
> they are usually mounted on are designed for the four point fuel pattern
> of a conventional four barrel carb, not the spray bar pattern of the
> Predator.
>
>> Has anybody run one on there Pantera?
>
> Not on a Pantera but a friend  borrowed my Holley Strip Dominator intake 
> and
> tested a Predator on a 372C in a 1969 Mustang.
>
>> I vaguely recall criticism (not from him) that they sometimes didn't idle
>> well.  But, I am running the risk of perpetuating a falsehood without
>> specific data I can recall where to find.
>
> The Predator circuit is an air bleed to lean out the car at idle. 
> Predator
> recommends that you do not run a PCV tap into the carb plenum as it can 
> screw
> up the carb signal.  The Holley Strip Dominator intake has the vacuum tap 
> on
> #8 runner.   Jim plumbed the PCV into that port.   Apparently the PCV
> (essentially a controlled vacuum leak) took the place of the idle circuit 
> air
> bleeds.  If he plugged the PCV port, the carb calibration went immediately
> rich and idled poorly.  With it hooked up, it idled well and worked great
> across the RPM range.  On the single plane Strip Dominator, it produced 
> very
> good low end torque, better than a dual plane with 4 barrel carb.  Be 
> aware
> they don't have an idle circuit and are difficult to cold start in weather
> below 50 degree F.  They are also tall and in the '69 Mustang, a Boss 429
> hood scoop was required for clearance.
>
>> In any event, I used to hear more about them and now I hear nothing. I
>> thought the company had disappeared
>
> Predator
> 810 Cross Street
> Lakewood, NJ 08701
> (732) 367-8487
> (732) 367-0148 fax
> www.predatorcarb.com
> Predator variable venturi carbs.
>
> The Predator was originally marketed as the Kendig carburetor.  I've got
> a book that shows Dyno Don's 351C powered Pro Stock Pinto witha pair of
> Kendigs.
>
> Dan Jones
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