TheHolden straight-six motor is a series ofstraight-six engines that were produced byGeneral Motors Holden at theirPort Melbourne plant between 1948 and 1986. The initialGrey motor was so dubbed because of the colour of thecylinder block, later motors came in the form of aRed,Blue,Black, and the four-cylinderStarfire engine. These engines were fitted to all Australian designed Holdens of the same years, and the four-cylinderStarfire notably also found its way into theToyota Corona (XT130). TheGrey motor is a different engine from the others, while theRed,Blue,Black, and even the Starfire are all inter-related with many common parts and castings.
| Grey engine | |
|---|---|
 | |
| Overview | |
| Production | 1948-1963 |
| Layout | |
| Configuration | Straight-six |
| Displacement |
|
| Cylinder bore |
|
| Piston stroke | 3.125 in (79.4 mm) |
| Cylinder block material | Cast iron |
| Cylinder head material | Cast iron |
| Valvetrain | OHV 2 valves per cyl. |
| Valvetrain drive system | Timing gears |
| Compression ratio | 6.8:1–7.5:1 |
| Combustion | |
| Fuel system | Carburettor |
| Fuel type | Petrol |
| Oil system | Wet sump |
| Cooling system | Water-cooled |
| Output | |
| Power output | 60–76 hp (45–57 kW) |
| Torque output | 100–119 lb⋅ft (136–161 N⋅m) |
| Chronology | |
| Successor | Holden Red engine |
TheGrey motor, built between 1948 and 1963, (the last on 2 August 1963) earned its name as the engine block was paintedgrey. Thisoverhead valve engine was first fitted to theHolden 48-215 (and variants) and mated to a three-speed column change gearbox. A three-speed GMRoto-Hydramatic 240automatic transmission was an option fitted in the latterEK andEJ series. The engine was based on the pre-World War IIBuick Straight-6 engine design,[citation needed] and saw only minor changes throughout its 15-year life.
It displaced 132 cubic inches (2,160 cc) in its original form as used by the 48-215 (1948). It developed 60 brake horsepower (45 kW). This engine remained in production for eight years - until the release of theFE series in 1956. At that point, power was increased to 72hp (53kW) by an increase in the compression ratio to 6.8:1. Holden replaced theFC in 1960 with theFB series, and its engine was bored out to 138 cubic inches (2,260 cc). The compression ratio was increased to 7.8:1. It developed 76brake horsepower (57 kW) at 4200 rpm and 120lb.ft (162N.m) at 1400rpm, providing superior performance to the competing four-cylinderAustin,Morris,Vauxhall andFord of Britain vehicles. The grey motor was a low stress design for high reliability and featured a lowcompression ratio. Due to sheer ubiquity, they were popular for racing, and were fitted to many open-wheelers, as well as racing Holdens. With the engines' low-endtorque, they also found their way into boats and machinery such asforklift trucks.
This engine ran a seven-port non-crossflowcast-iron cylinder head. There were three Siamese (shared) inlet ports for cylinders 1–2, 3–4 and 5–6, two individual exhaust ports for cylinders 1 and 6, and two siamese exhaust ports for cylinders 2–3 and 4–5 in a layout on one side of the head casting. The inlets were fed by a single-barrel Strombergcarburettor in common and fitted with a traditional Kettering ignition by coil and distributor. The electric system was six volts in the 48-215 and FJ. The earliest grey motors (approximately 100,000) were fitted withDelco-Remy accessories, althoughLucas andBosch equivalents throughout the motor's lifetime replaced these.
The very first production grey motor (1948) was number 1001, and they continued in a single sequence until July 1956, when the prefix "L" was introduced.[1] The change affected all engines numbered L283373 and above, signifying the 12-volt negative-earth engines as fitted to the all new FE model.[citation needed] The prefix "U" was introduced for motors with the original electricals as fitted to the FJ utility and panel van models, which ended in February and May 1957 respectively. The change was effective from engine U283384.[1] The prefix "B" was introduced and the number sequence reset with the introduction of the 138 cubic inches (2.3 L) displacement engine, and ultimately this was replaced by a "J" prefix for motors fitted toEJ vehicles in 1962.
| Red engine | |
|---|---|
 | |
| Overview | |
| Production | 1963–1980 |
| Layout | |
| Configuration | Straight-six |
| Displacement |
|
| Cylinder bore |
|
| Piston stroke |
|
| Cylinder block material | Cast iron |
| Cylinder head material | Cast iron |
| Valvetrain | OHV 2 valves per cyl. |
| Valvetrain drive system | Timing gears |
| Compression ratio | 8.8:1-9.4:1 |
| Combustion | |
| Fuel system | Carburettor |
| Fuel type | Petrol |
| Oil system | Wet sump |
| Cooling system | Water-cooled |
| Output | |
| Power output | 77–147 PS (76–145 hp; 57–108 kW) |
| Torque output | 183–263 N⋅m (19–27 kg⋅m; 135–194 lb⋅ft) |
| Chronology | |
| Predecessor | Holden Grey engine |
| Successor | Holden Blue engine |
| Engine | Displacement | Compression | Power | Torque | ||
|---|---|---|---|---|---|---|
| bhp | kW | ft·lb | N·m | |||
| 173 cu inRedI6 | 2.8 litres (2,835 cc) | Low | 112 | 84 | 160 | 220 |
| High | 118 | 88 | 168 | 228 | ||
| 202 cu inRedI6 | 3.3 litres (3,298 cc) | Low | 129 | 96 | 190 | 260 |
| High | 135 | 101 | 194 | 263 | ||
Superseding theGrey motor, theRed motor was manufactured between 1963 and 1980. This was a completely new engine and in no way a further development of the grey motor. It featured a seven-bearing crankshaft, full flow oil filter and hydraulic valve lifters. Denoted by thecylinder block paintedred, the engine made its debut in theHolden EH in capacities of 149 cubic inches (2,447 cc) and 179 cubic inches (2,930 cc) (or HP) producing 100 and 115 brake horsepower (75 and 86 kW) respectively. This was a power increase of 33 per cent and 53 per cent over the grey motor.[2]
Initially the engine capacity was not cast on the blocks. The EH model with the 149 CID block was blank and the 179 CID was designated with the letters “HP” (to denote the high performance engine). The 179 capacity marking cast in raised numbers, located on the side of the block behind the generator/alternator, began in January 1965 in readiness for the HD model due for release in February 1965. This also included the last of the EH commercial models that were ending production in June 1965. All engines from January 1965 had their capacities cast on the block.
All red engines manufactured prior to January 1968 had forged steel crankshafts.(with the exception of some HR model field test vehicles).With the opening of Holden’s Nodular Iron Foundry (the only one in Australia) on 10 February 1967 by Prime Minister,Harold Holt production of cast nodular iron crankshafts, along with other products, could begin.
The Nodular Iron crankshafts were first released for field testing insome engines fitted in the HR model. Starting from engine number A121465, in February 1967, they were identified by using a different harmonic balancer with a vee annular groove. Full production release of the so called “cast” crankshaft in the red motor was from January 1968 in the HK model. The forged steel crankshafts, however, still remained in the optional engine variants such as the X2, all 186S engines and the LC 186 XU1. The standard engine colour also changed in the HK to Rocket Red from the previous “Holden Engine Red”.In 1978 Holden changed the colour of the Red motor to a new variation called Rocket Red MkII (Dulux code 31036).
| Blue engine | |
|---|---|
 | |
| Overview | |
| Production | 1980-1984 |
| Layout | |
| Configuration | Straight-six |
| Displacement |
|
| Cylinder bore |
|
| Piston stroke |
|
| Cylinder block material | Cast iron |
| Cylinder head material | Cast iron |
| Valvetrain | OHV 2 valves per cyl. |
| Valvetrain drive system | Timing gears |
| Compression ratio | 8.8:1-9.0:1 |
| Combustion | |
| Fuel system | Carburettor |
| Fuel type | Petrol |
| Oil system | Wet sump |
| Cooling system | Water-cooled |
| Output | |
| Power output | 103–114 PS (102–112 hp; 76–84 kW) |
| Torque output | 192–231 N⋅m (20–24 kg⋅m; 142–170 lb⋅ft) |
| Chronology | |
| Predecessor | Holden Red engine |
| Successor | Holden Black engine |
TheBlue specification debuted in the 1980VC Commodore.[4]
The blue motor was a development of the earlier red engine, and incorporated several improvements; the biggest of these changes was the complete redesign of the cylinder head. The head was upgraded to a 12 port design with individual ports for each cylinder, and a revised T5 camshaft. The crankshaft for the 3.3-litre engine now had counterweights on each throw, and stronger connecting rods were used. A two-barrel Varajet carburettor was standard, as was a dual outlet exhaust manifold and a Bosch HEI distributor. The blue motor was made in 3.3- and 2.85-litre versions.
| Black engine | |
|---|---|
 | |
| Overview | |
| Production | 1984-1986 |
| Layout | |
| Configuration | Straight-six |
| Displacement | 202 cubic inches (3,298cc) |
| Cylinder bore | 3.625 in (92.1 mm) |
| Piston stroke | 3.250 in (82.6 mm) |
| Cylinder block material | Cast iron |
| Cylinder head material | Cast iron |
| Valvetrain | OHV 2 valves per cyl. |
| Valvetrain drive system | Timing gears |
| Compression ratio | 8.8:1 |
| Combustion | |
| Fuel system | |
| Management | Jetronic for EFI variant |
| Fuel type | Petrol |
| Oil system | Wet sump |
| Cooling system | Water-cooled |
| Output | |
| Power output | 117–144 PS (115–142 hp; 86–106 kW) |
| Torque output | 232–266 N⋅m (24–27 kg⋅m; 171–196 lb⋅ft) |
| Chronology | |
| Predecessor | Holden Blue engine |
| Successor | Nissan RB engine (RB30E) |
TheBlack specification was introduced in the 1984VK Commodore.[5] The black engine was only produced in 3.3-litre displacement, and in carbureted and fuel-injected versions. The carbureted engine was almost identical to the previous blue engine, the main difference being in the use of computer controlled spark timing (EST) taking its timing pick-up from the flywheel area. The ports were slightly wider spaced, meaning the manifolds will not simply interchange. The fuel-injected version usedBoschLE2-Jetronicmultipoint fuel injection and featured a long-runner intake manifold, 6-3-1 tubular exhaust manifold and a conventional HEI ignition.[6] It also had slightly different cylinder head intake ports for improved breathing (along with location notches for the fuel injectors) and revised camshaft specifications, and delivered superior performance and fuel economy over the carbureted version.[7]In the 1986VL Commodore, Holden replaced the Australian-made and designed six-cylinder engines with theNissanRB30E andRB20E engines. Pending emission standards and the requirement for unleaded fuel made it difficult to re-engineer the Australian engine.[8]
| Starfire engine | |
|---|---|
 | |
| Overview | |
| Also called |
|
| Production | 1978-1986 |
| Layout | |
| Configuration | Straight-four |
| Displacement | 115 cubic inches (1,892 cc) |
| Cylinder bore | 3.500 in (88.9 mm) |
| Piston stroke | 3.000 in (76.2 mm) |
| Cylinder block material | Cast iron |
| Cylinder head material | Cast iron |
| Valvetrain | OHV 2 valves per cyl. |
| Valvetrain drive system | Timing gears |
| Compression ratio | 8.7:1 |
| Combustion | |
| Fuel system | Carburettor |
| Fuel type | Petrol |
| Oil system | Wet sump |
| Cooling system | Water-cooled |
| Output | |
| Power output | 79 PS (78 hp; 58 kW) |
| Torque output | 136 N⋅m (14 kg⋅m; 100 lb⋅ft) |
| Chronology | |
| Predecessor | Opel cam-in-head engine 1.9L |
| Successor | GM Family II engine 1.6L-2.0L |
This 1.9-litre (1,892 cc) powerplant, known as theStarfire engine, was effectively Holden's existing 2.85-litre 173 cu in straight-six with two cylinders removed.[4] Designed and built in Australia to satisfy local content rules, it first appeared in 1978 during the UC Sunbird's production run, replacing the Opel 1.9-litre cam-in-head unit used in LH, LX and earlier UC Torana/Sunbird 4-cylinder models.[citation needed]
Peak power output for the Starfire was 58 kW (78 hp), with a 17.5 second acceleration time from 0–100 kilometres (0–62 mi) in the VC Commodore.[9] This variant's performance meant the need to push the engine hard leading tofuel consumption similar to the straight-sixes. Due to this, it was often nicknamed asMisfire orBackfire. This engine was replaced in the Australian market by theCamira's OHCCamtech unit, however, it continued to be used until 1986 in New Zealand, where it was used to power four-cylinder versions of theVK Commodore.
This engine was also used byToyota Australia to meet local parts content regulations for theCorona XT130.[10] Engines installed in Toyotas received some slight differences in the form of a unique camshaft, manifold, and carburettor. Toyota called the engine the "1X" and it had a slightly different power curve: 58 kW (78 hp) at 4800 rpm and 136 N⋅m (100 lb⋅ft) at 2400 rpm.[10]
ADR27A was anAustralian Design Rule specifying regulations for fuel evaporative and exhaust emissions for Australian passenger motor vehicles effective from 1 July 1976 in order to reduce air pollution.The following engines were ADR27A compliant:
These engines were fitted with emission control systems which generally resulted in reduced engine output. The following table compares the output of the 202ci Red engine in pre- and ADR27A-compliant versions:
| Power | Torque | |
|---|---|---|
| pre-ADR27A | 135 hp (101 kW) @4400rpm[11] | 194 lb⋅ft (263 N⋅m) @2000rpm[11] |
| ADR27A-compliant | 109 hp (81 kW) @3900rpm[12] | 185 lb⋅ft (251 N⋅m) @1400rpm[12] |