Kinsler_Handbook_#32 December 2017

Kinsler Fuel Injection, Inc, 1834 THUNDERBIRD TROY, MICHIGAN 48084 U.S.A. Phone (248) 362-1145 Fax (248) 362-1032 167 SHUT-OFF VALVES USAGES Typically used to shut off an engine with constant flow fuel metering. On this type of system it is not wise to shut off the ignition to stop the engine. After killing the ignition system, the engine “winds down”, and the mechanical fuel pump which is still turning pumps fuel into the engine. A shut-off valve allows the operator to shut off the engine cleanly; prolonging engine component life, ease in restarting, and reduces oil dilution. It also aids in obtaining reliable spark plug readings. SHUT-OFF MOUNTING TYPES OF SHUT-OFF VALVES Mechanical valve - spool type and seal assisted ball. Spool Type Acceptable for internal sealing when in good condition. The spool rotates inside a housing without the aid of any seals to prevent leakage around the spool. Typi- cally smaller in size than the seal assisted ball type valve. The fit of the spool to the housing is critical, a worn spool or housing will allow excessive amount of leakage through the valve assembly. This may allow the engine to continue to run, or fuel to leak past the valve when the engine is not running. Ball Type - Seal Assisted Excellent for internal sealing. The ball rotates on a large sealing surface stopping the flow of liquid on the inlet and outlet. A spring loaded seal on both sides of the ball prevents leakage around the ball. While this style is more difficult and costly to manufacture it is the valve of choice due to it’s positive shut off. If the shut-off is mounted with a threaded fitting, do not screw any other item to the valve.... under typical engine vibration the additional weight may tend to fatigue the fitting that mounts the valve and cause it to break. When mounting a shut-off valve be sure that the valve itself and the link- age\cable\etc. has plenty of room for operation. Always take into consideration the movement of parts under torque stress, or vibration, such as body panels, hood, suspension, etc. On a constant flow injection it is always best to mount the shut-off valve at the inlet of the barrel valve (see “Preferred Plumbing Schematic” on Page #112), because: A) If the shut-off is pulled at high engine speed, the fuel will be able to bypass back to the tank through the main bypass and the high speed bypass, thus avoiding excessive fuel pump pressure. Since excess pressure can ruin a fuel pump instantly, it is always best to pull the shut-off at low RPM or install a relieving type shut-off, (normally called a 3-way shut-off). B) When the engine is shut off, the fuel in the hoses and filter absorbs heat and expands. Mounting the shut-off at the barrel valve will force the expanding fuel back toward the tank rather than into the engine. DO NOT mount any two way shut-off valve directly on the pump outlet, since the fuel has no place to go when the shut-off is pulled.... this could easily ruin the pump or rupture a hose. ! © 2017 DO NOT USE a shut-off to stop fuel flow to a pump that is rotating. The fuel lubricates the pump, shutting off the fuel could cause damage to the pump. A shut-off can be used to allow the servicing of a pump inlet filter, removing a pump, or removal of a fuel tank. DO NOT INSTALL a shut-off that will “dead head” the pump. Always be sure that an adequate flow path back to the tank is available. KW pump with #6350 shut-off Spool Ball and components