NOTES ON INSTALLATION AND CALIBRATION

RACING CARS

PART 1.       INSTALLATION

(a)           Mounting and Driving the Metering Distributor

               The position chosen for the metering distributor must be such
               that sufficient space is available for fitting, connecting up,
               etc., and that the unit is not close to an exhaust pipe or manifold.
               The metering distributor can be mounted at any angle between
               horizontal and vertical. It is essential, however, that the
               running petrol seal on the drive shaft should be kept wet with fuel,
               so that if the unit is mounted horizontal, the leakage fuel tube
               on the drive end flange must be positioned above horizontal.

               A half-engine speed drive is necessary for the metering distributor
                rotor, the torque required being on the order of 0.5 Lbf ft. The
               drive is transmitted to the rotor through an Oldham-type coupling.

   Suggested methods of driving the metering distributor are either:-

                       ( i ) by a cogged belt drive.
                
                      ( ii )  by an angled drive from the ignition distributor drive shaft.

                      ( iii ) by direct camshaft drive, although in this instance
                               some special intermediate coupling may be necessary
                               to offset the effects of torsional oscillation.

               For racing applications, which are frequently "one-off" installations,
               method ( i ) is preferred, since it does not necessitate special castings
               or machining of major engine components. It is necessary, however,
               to employ an adaptor which incorporates a bearing and petrol seal,
               details of which will be provided be the Lucas P.I. Design Office.
               A rubber cogged belt. 0.5 in (12.7 mm) wide and 0.375 in (9.37 mm)
               pitch, will be found to give successful results.

( b )         Manifold Design

               The best manifold arrangement for high-performance racing engines is
               undoubtedly one having separate intake ducts for each cylinder, with
               a slide-type throttle valve situated conveniently close to the cylinder
               head (see illustration LSK487). It is appreciated that a slide-type
               throttle mechanism of this nature necessitates precision engineering
               with its accompanying cost, and a less expensive alternative frequently
               adopted is the use of individual butterfly valves in the intake ducts.

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