SOME DATA ON FAIL-SAFE OIL PRESSURE PROCEDURES


| September/October 1978



Magneto ignition

11 Brookside Drive, Wilbraham, Massachusetts 01095

FOR COIL AND IGNITION

Switch must be 'open' (off position) for starting. Turn 'on' for oil fait protection. Should oil pressure fail, the 'idiot light' sending unit will ground out the ignition current going to the points and spark will cease at once. Since ign. is grounded out through the coil's load, the wires will not get hot and/or overload the circuit. Maximum current draw is the same as when points are closed: about 2 amps.

FOR MAGNETO IGNITION

Here the safety feature functions like a remote control magneto kill switch-which it is, since the oil light switch grounds out when there is no pressure. To start the SPST switch is in the 'open' (off) position - so that the oil switch won't ground out the mag. After the startup, close the switch for Ioss-of-oil-pressure protection.

You can save wire and time by using a single-contact style oil sending switch such as used on Chrysler products. Slant six and most V-8 engines. These switches are closed when no pressure exists-thus supplying a ground for the bulb; they open with pressure, eliminating the ground.