Carter BBD
Carburetor Alternatives
options for ditching
this problematic carb - part 2 |
tech |
Recap:
In the last few years of the CJ series and the first few
years of the Wrangler YJ Jeep outfitted the 4.2L (258) 6
cylinders with an electronic carburetor referred to as the
BBD. The Carter BBD is a two barrel carburetor that
came in two variations, one is computer controlled and has a
stepper motor on the back side. The computer controlled
version was used after 1981. Both have similar
problems and considering they haven't been "new" in
approximately 20 years alternatives are sometimes the best
option to regain reliability and performance.
The BBD carb has a nasty
reputation, most anyone that has owned a Jeep with one of
these can relate. Sputtering, stalling, stalling at
every stop sign and only running off idle. Very
frustrating to deal with.
There are several popular
alternatives; electronic fuel injection systems by Mopar,
Howell, Holley and the home grown; carburetors by Weber and
Motorcraft. We will explore the positives and
negatives in all three types.
Carburetors
Carburetors are simplistic in
design and operation compared to electronic fuel injection.
Typically all mechanical, the amount of air moving through
the carb dictates the amount of fuel being delivered.
Usually carburetors have a fuel bowl that stores a small
amount of fuel, an electric or manual choke, and vacuum
ports. System failure with a quality carburetor is
uncommon when compared to fuel injection systems with
computers and sensors. A drawback to a carburetor is
they are prone to flooding the engine when the Jeep is at
extreme angles.
NOTE: Some of
these carburetors may not be emissions legal - check your
state before purchase
Weber
- This is probably the most common carb conversion for
the 6 cyl Jeeps. The Weber is a very reliable, all
mechanical carb that improves performance and drivability.
The Weber
is designed to supply the proper amount of fuel determined
by the demand put on the engine. When demands are
small, only the primary barrel is used, and when demands
increase, the second barrel is used in to deliver the
performance needed. Use of thie carb allows removal of
all the electronics associated with the BBD.
The 32/36 DGEV model claims 18% hp
increase over the stock factory carb as well as 10-20% fuel
economy increase. The 38 DGEV model is designed for
higher power applications where headers, cam, and
aftermarket intake manifold are used. $$
Motorcraft
- This swap is the least expensive and can provide
excellent results. While none of us here have
personally performed this swap research has shown others
have been very pleased with the outcome. Most agree
this swap will definitely make your Jeep non-emissions
legal. What to use: A Motorcraft (sometimes
called an Autolite) 2100 series carb typically found on an
AMC 304 or Ford 302 and a 2bbl manifold if your Jeep is not
equipped with one. The correct size will have "1.08"
in a small circle cast on the drivers side of the carb body.
An adapter will be required to fit the carb to the Jeep
manifold. A 2bbl to 2bbl adapter from TD Performance
Products adapter no. TRD-2086 should do. Some changes
to the throttle cable assembly and other components may be
necessary. $
Rocktaxi.com has an in-depth article on this swap, if
you are interested visit them for more info.
back to
part 1 - Fuel Injection |