Ignition Timing

Set timing with engine at idle speed, and with distributor vacuum line disconnected and plugged.

Engine

Without A.I.R.

With A.I.R.

95 HP (Synchro-mesh)

6° BTDC

9° ATDC

(Auto. Trans.)

14° BTDC

4° ATDC

110 HP (Synchro-mesh) ⁽¹⁾

14° BTDC

1° ATDC

(Auto. Trans.) ⁽¹⁾

14° BTDC

4° BTDC

(Auto. Trans.) ⁽²⁾⁽³⁾

24° BTDC

140 HP (Synchro-mesh)

18° BTDC

3° BTDC

(Auto. Trans.)

18° BTDC

8° BTDC

180 HP (Synchro-mesh) ⁽⁾

24° BTDC

⁽¹⁾	Without Air Conditioner.

⁽²⁾	With Air Conditioner.

⁽³⁾	DO NOT exceed specifications of 24° BTDC.

Fig 1: Corvair Firing Order

Courtesy of GENERAL MOTORS COMPANY