Historically, Ford 302 has two distinct firing orders one is for non-HO (High Output) engines, and second is HO firing order. The traditional firing order is (1-5-4-2-6-3-7-8) used on non-HO (High Output) engines, and the HO firing order is (1-3-7-2-6-5-4-8) adopted from the 351 Windsor engine.
This comprehensive article examines both firing orders in detail, exploring their technical specifications, historical context, practical applications, and the engineering reasons behind Ford’s transition to the HO configuration.
Cylinder Numbering and Engine Layout
Before we understand Ford 302’s firing order we need to check properly cylinder numbering system. The Ford 302 has a standard cylinder layout taken from V8 setup where this numbered from front to back.
From the side bank it contains cylinder 5, 6, 7, and 8, with cylinder 5 at the front. Unlike any other GM engines that rotates clockwise this Ford rotates counter-clockwise.
Firing Order Specifications
The Ford 302 has two different firing orders which we are going to discuss below.
Standard Firing Order
Traditional firing order for Ford 302 engines is 1-5-4-2-6-3-7-8. This order was also used on the non-HO 302 engines found in standard passenger cars, trucks, and Broncos until the early 1980s.
This firing order was designed to optimize for power delivery while minimizing stress on crankshaft and bearing components.
High Output (HO) Firing Order
From the 1982, Ford started new order 1-3-7-2-6-5-4-8 which was borrowed from the 351 Windsor engine and became standard on all 302 HO engines through 1995. It was also used in the 1993-1995 Gen 1 Lightning trucks equipped with the 351 Windsor engine.
| Engine Type | Years | Firing Order | Distributor Rotation |
|---|---|---|---|
| Standard 302 | 1968-1981 | 1-5-4-2-6-3-7-8 | Counter-clockwise |
| 302 HO | 1982-1995 | 1-3-7-2-6-5-4-8 | Counter-clockwise |
| 351 Windsor | 1969-1996 | 1-3-7-2-6-5-4-8 | Counter-clockwise |
Historical Evolution and Engineering Reasons for the Change
Ford’s transition from the traditional firing order to the HO configuration was mainly for the tuning for performance.
- Vibration and bearing wear: The traditional firing order (1-5-4-2-6-3-7-8) had some firing load on crankshaft throws, particularly affecting numbers 7 and 8 rod bearings causing significant vibration in the engine area. The HO firing order (1-3-7-2-6-5-4-8) evenly distributes the loads throughout all the points to reduce vibrations and have higher engine life.
- Inductive crossfire prevention: The HO firing order has reduced inductive crossfire between spark plug wires. making it efficient for wiring and technical advantage.
- Engine Sound: Ford has stated that this change in firing order has improved their firing note and making it more sound like iconic Mustangs.
