The fuel injected Jacobs engine is equipped with a time tested Bendix RSA series fuel servo with upper and lower adapter plates that duplicate the bolt pattern and overall height of the NA-R7A carburetor that is replaced. A Bendix flow divider and lines deliver fuel to GAMI fuel injection nozzles fitted in each intake pipe. The original engine driven fuel pump is replaced with a similar unit set to the higher pressure requirements of the fuel injection system, and an electric boost pump provides fuel for starting, as well as providing redundancy.

Carbureted Jacobs engines must deliver their atomized fuel through an induction system that invariably results in a wide variation of mixtures, cylinder to cylinder. When a carbureted engine is leaned, the engine is leaned to the leanest cylinder, while all other cylinders are left in varying degrees of too rich. This means a waste of fuel and lower power production in all but one of the cylinders. Carbon and lead deposits are not burned efficiently in cold cylinders, which results in build-up on the valves and seats, a loss of compression, and ultimately cylinders that require maintenance. Carburetor icing is a constant danger and for those interested in aerobatics, float carburetors will not run inverted for any length of time.

With the fuel injection system from Radial Engines, Ltd., your Jacobs engines will deliver only air through the induction system, and metered fuel is not introduced into the engine until it reaches the patented GAMI nozzles, only one inch from the intake valve. These GAMI nozzles are customized to each individual cylinder to deliver the precise amount of fuel to match the airflow of that cylinder. As a result, exhaust gas temperatures (EGTs) are closely matched cylinder to cylinder, each cylinder produces the power that it is capable of producing with an optimum mixture, horsepower goes up and fuel consumption goes down. Since individual cylinders are no longer operating rich and cold, lead and carbon deposits no longer build up at the rate seen with carbureted engines and required cylinder maintenance goes down. Fuel injection demonstrates an extreme resistance to icing and the system operates equally well in any flight attitude.

Installing the fuel injected engine begins by removing the carburetor, fuel pump, intake pipes and priming system from the carbureted engine and replacing them with the fuel servo with adapters, engine driven and electric boost fuel pumps, specially modified intake pipes, flow divider, GAMI nozzles, and fuel injector lines. If a fuel flow indicator is not presently installed in the aircraft, it is necessary to install such a system. The electric boost pump and fuel flow meter require an additional circuit breaker and switch that can be added to the aircraft’s existing electrical panel, or a sub panel may be added. After installation, the engine is test run, cylinders are monitored for evenly matched EGTs, and GAMI nozzles are custom fit to each cylinder for maximum efficiency. Three Authorized Installation Facilities throughout the United States (listed below) have been designated and trained in the installation and maintenance of the Radial Engines, Ltd. Jacobs R755 Fuel Injection System. Any of these facilities may be contacted for service.

The fuel injection hardware package comes complete with Bendix fuel injection servo with upper and lower adapter plates, flow divider, fuel injection lines, GAMI nozzles, Pesco engine driven fuel pump, electric boost pump, modified intake pipes, Aeroquip firesleeved hoses, and all associated nuts, bolts, and clamps.

The fuel injection system is $15,900 plus installation.