From its inception the 911 engine was a high
performance design, built around carburetion and tuned
exhaust. In spite of all the "improvements"
along the lines of fuel injection and emission control,
the 911 with carburetors is still a good fit. Mechanical
fuel injection was never totally successful on a street
engine because of erratic mixture control and poor
atomization at lower RPMs. CIS fuel injection is oriented
towards emission control and, after 1974, is also coupled
with restrictive exhaust system.
PMO is the original manufacturer of 911 carburetor
conversions and we are the only company in the world
dedicated exclusively to providing 911 Carburetor
Conversions. We manufacture sixteen different manifolds
for the 911. They are all of the highest quality; cast of
prime, heat treated aluminum. Bore matching,
porting-polishing is standard. No matter what 911 engine
you may have, from 2.0 to 3.8 liters, we have the height,
port combination and bottom flange shape to fit your
application. For instance, our 2.7 CIS manifold has the
correct 35mm port size and correct CIS shape bottom
flange. Adding the CIS shape to the bottom flange of the
manifold is a PMO innovation. This flange eliminates the
need to weld and grind on the cylinder heads to fill the
notches that are in the CIS ports. The 3.6 litre manifolds
come with triangular flanges and insulators to bolt right
up to the cylinder heads.
We started manufacturing linkage when the factory
discontinued the Weber crossbar. Our crossbar uses the
original Weber configuration and improvements include
pressed-in, fully machined bearings, one piece throttle
arm on the left side, replaceable hard ball pins, and
heliarced assembly. The current factory Zenith crossbar
has crimped bearings, two piece tack welded throttle arms
on the left side, staked-in ball pins and brazed assembly.
Our small bell crank has a solid silicon bronze bearing,
one inch in length, whereas the factory bell crank is
constructed with a hollow tube and two plastic bushings.
Our short press rods are machined out of hex rod; the
factory press rods are only a rod with a nut brazed in the
The finest Air Cleaner element is the K & N. We
have custom designed our own filter cases to accept the K
& N elements. Our air cleaners come in two heights,
one shorter for air conditioned cars. The short height
element was manufactured specially for us by K & N. In
turn we manufactured short velocity stacks for use in this
unit. Our kits also include a K & N oil tank breather.
To prevent hydrolock our kits now include the Watershield
top cover assemblies.
Another innovation by PMO is our fuel pressure control
unit. This enables you to retain your high pressure, high
volume pump for use with the PMO Carburetors. Each
pressure control unit has a built-in pressure gauge and is
fully adjustable to set the fuel pressure while the engine
is running. By retaining your stock high volume fuel pump
in combination with our unit there is never a worry about
your engine exceeding the capacity of a low pressure/low
volume fuel pump.
Another standard item included in our kits is our heat
insulator plates with longer studs. The purpose of these
is to stop float bowl percolation which leads to flooding.
Naturally, these come in sets custom fitted to your port
size and flange configuration. High pressure fuel line and
a full set of required gaskets are included. Also included
are full and complete instructions. When you order a PMO
kit all you need is your tools and time. Nothing is left
We offer more 911 Carburetor Conversions than ANYONE
else. Having experienced numerous combinations gives us a
wide and varied knowledge of our specialty.
We manufacture a complete selection of venturis to
provide the proper size for each application. Venturis are
machined out of heat treated aluminum to an Aero-Space
quality finish. The jetting and venturi combinations
included in our kits have been worked out through years of
experimentation on the road, track and dynamometer
Remember there is only one company that originated the
911 Carburetor Conversion Kit, manufactures all the
necessary components to integrate the PMO carburetors to
your engine, has the highest quality components all the
way through, has the widest selection of 911 conversion
kits, and has the most experience with 911 carburetor
conversions. That company is PMO.