The 132.5ci (2160cc) Grey In-Line Six

This was the very first Holden engine, painted grey and known as the 'Grey Motor'. The first version boasted 61hp (45kW) and was renown for it's great torque characteristics. This engine remained in production for eight years - until the release of the FE Holden in 1956. At that point, power was increased to 72hp (53kW) by an increase in the compression ratio to 6.8:1. A stiffer piston head and bigger valves also contributed to the increased power. In 1958 this engine gained a little more power through an altered camshaft and a further increase in the compression ratio to 7.0:1. Even at that, it was basically under-stressed. In total, more than 637,000 of the 132.5ci (2160cc) grey motors were built.

This engine appeared in 1960, powering the FB. Although uprated to 7.25:1 compression and 76hp (56kw), it showed little improvement in performance because the car was considerably heavier than its predecessor. This motor remained unchanged right through to the end of production of the "New Look" EJ Holden of 1962. In total, from the 48-215 (FX) through to the end of the EJ, around 1,178,028 grey motors were built in a fourteen-and-a-half year period.

The 149/179/X2/161 and 186 Red In-Line Six

With the introduction of this new engine in August of 1963, GM-H celebrated the change by painting the engine block red - hence the name. With a shorter stroke, bigger bore and higher compression, it offered 33 per cent more power than the grey engine in its 149ci (2441cc) form and 53 per cent more power as a 179ci (2933cc) unit. The 149 poked out a healthy 101hp (74kW) and the 179 achieved 117hp (86kW).

In February 1965Holden launched the HD with an X2 option - a 179 fitted with twin carburettors, a modified camshaft and low restriction exhaust. The result: the first factory go-fast, with 140 horses (105kW) under the bonnet.

Refining the project further saw the twin-carb X2 upgraded to 145hp (109kW) in April 1966 in the all-new HR, making it the most powerful Holden engine to date. A new, two barrel, single carby version of this engine (the 186ci or 3047cc), released in June 1967 - the 186S - offered no power gains but did provide smoother power and access to the first holden four-on-the-floor. By this time the red engine line-up comprised the 161 (2638cc), which also had a low compression variant available, the 186 (3047cc)six, and the high performance 186S. These engines remained right through to the end of HG. Up until that point, the 149 to 186 red series engines had powered more than 1.2 million Holdens, from the EH to the HG.