Holden V8 engine

In 1964 Ford and Chrysler in the US released V8 versions of their respective Falcon and Valiant models which Holden expected to soon be released in locally assembled or produced versions. In response, in January 1965 the company's engineering division initiated a forward engine program review and concluded that by 1969 a V8 option was a necessity for Holden, with forecasts of 35 per cent of all Holdens sold in 1970 to be V8s, rising to 50 per cent by 1975. Initially six capacities from 237-308ci (3883-5044cc) were planned over a 12-year life cycle, but early in the design phase this was reduced to just two, an 'economy' 253ci (4143cc) and an enlarged 'performance' 308ci (5044cc) version, which became known as the 4.2L[lower-alpha 1] and 5.0L respectively.[2]

Design targets of a weight of 525lb (238kg, which was lighter than equivalent US engines, and a net output of and 161bhp at 4000rpm and 263 lb-ft at 2400rpm were set for the 308, which was mechanically identical to the 253 except for a larger bore and bigger pistons, along with heavier counterweights on the crankshaft to compensate for the increased reciprocating mass. Originally an alloy inlet manifold was specified to reduce weight, but this was changed to iron when problems were encountered in the casting process. The exhaust manifolds were also cast iron but the timing case cover remained as an alloy item.[2][3]

The initial pre-production engine was the 253, which not only met but greatly exceeded the design targets. The complete engine assembly from fan to flywheel and all auxiliaries weighed in at 460lb, around 12% less than the design target, while net output for the higher compression (9.0:1) version fitted with a 2-barrel carburettor[lower-alpha 2] was 185hp with 262 lb.ft of torque, which matched or exceeded the targets set for the larger 308. The design was also very compact with a width of 22 inches, and was only 80lb heaver than the 186ci straight six, but producing over 40% (55hp) more power than that engine in standard form. The first running engine was delivered in October 1966. Unfortunately, the engine failed after just four days testing from a seized oil pump; however, the problem was found to be caused by swarf residue rather than a fault in the design or the quality of the components. Further testing proved that the engine was smoother and more durable than Holden's six cylinder, no mean feat as the 186 was considered a smooth and reliable engine in its day.[3][5]

The new engines were initially intended to be offered as part of the 1968 Holden HK range, but production issues caused the project to run behind schedule and consequently 307ci and 327ci Chevrolet engines imported from the US were used instead. The 253 made its public debut in the Holden Hurricane concept car at the 1969 Melbourne International Motor Show, albeit it in a highly modified form featuring increased 10.1:1 compression, big cam and solid lifters, and producing over 250 horsepower (190 kW). The new engines saw their production release later that year in the HT model range, with the 253ci replacing the 307ci and the 308ci replacing the 327ci (an imported 350ci was still available as an option). The 253 was initially only available with a 2-barrel carburettor while the 308 was only available with a 4-barrel carburettor.[2] The engines were available across all models in the range, including the 2-door Monaro coupe.

5.0 L; 307.8 cu in (5,044 cc) V8

The V8 engine also appeared from 1971 in the Statesman range of large size luxury cars which Holden established as a separate marque replacing the Holden-badged Brougham. Initially both the 253 and 308 were offered across the Statesman range but after the HJ the 253 was dropped and the 308 was standard for the HX, HZ and WB.

In 1974, both the 253 and 308 engines were added to the Torana range for the first time in the LH series (after an aborted attempt by Holden Dealer Team boss Harry Firth to introduce the V8 to the smaller LJ in 1972 which was stopped by the "supercar scare"). The engines were also offered on the revised LX released in 1976, which from July of that year saw emission-controlled versions of the 'Red' engines introduced to comply with the new ADR27A regulations on fuel and exhaust emissions. The V8 was dropped as an option in the final model in the Torana series, the UC released in 1978.

In 1978 with the introduction of the new smaller Commodore as Holden's family car, the final versions of the 'Red' 253 and 308 were available with the initial VB. In 1980 the revised VC saw the introduction of the revised 'Blue' series of engines, available in both capacities, which continued through to the VH in 1982. The VC also saw the introduction of high-performance versions of engine in limited-edition vehicles produced in partnership with Peter Brock's Holden Dealer Team (HDT), with various models subsequently appearing through to the VL range in 1987, when relations between the two companies soured and Holden severed its ties with HDT.

With the release of the 'Black' engine in the VK Commodore in 1984, the 253 was dropped as an option and the 308 was the only capacity of the V8 now available in the Commodore. However, the smaller engine continued to be available in the Holden WB commercial vehicles e.g. the One Tonner cab chassis. In 1985, a destroked version of the 308, known as the 4.9L or 304, was introduced to allow the VK to compete with a lower minimum weight (1325kg, a saving of 75kg) under the 4501-5000cc regulations of Group A touring car racing.[6]

In 1988 fuel injection appeared for the first time on a Holden V8 engine, on the VL Commodore SS Group A produced by Holden Special Vehicles (HSV), Holden's new performance partnership with British-based Tom Walkinshaw Racing (TWR); however, this was not a standard production engine, which still continued to feature a carburettor. Later that year the VN introduced the 5000i engine with new cylinder heads and multi-point fuel injection which represented the most extensive redesign of the standard production Holden V8 since its launch in 1969. This engine continued in all subsequent Commodores until 1999 (2000 for the VS Series III Ute), when it was replaced by the US-made all-alloy Gen III LS1 5.7L V8 in the VT Series II.

The Holden V8 is a water-cooled naturally-aspirated 4-stroke gasoline engine featuring eight cylinders arranged in a 90 degrees vee-formation. It is an overhead valve design featuring two valves per cylinder with a camshaft centrally located in the engine block above the crankshaft, driven by a timing chain attached to toothed sprockets, with the camshaft in turn driving the distributor and oil pump. Valve actuation is by hydraulic lifters and pushrods to rocker arms (roller rollers in some models) in the cylinder heads; the lifter bore angle in the engine block is 45 degrees from the block centerline. A belt-driven radiator fan and water pump are located on the front of the engine block taking drive from the main pulley, as is the alternator. The cast iron engine block features a separate pressed steel non-stress bearing sump assembly with the crankshaft located within five main bearing journals secured with 2-bolt bearing caps; 4-bolt main bearing caps featured on later performance versions.[2][3]

Aftermarket Holden V8 alloy cylinder heads showing different valve layouts; pre-1988 (top) and post-1988 (bottom

The cast iron cylinder heads are a cross-flow design with wedge-shaped combustion chambers and a single spark plug. In early versions of the engine the inlet and exhaust valves were arranged in a "mirrored" configuration around a longitudinal mid point in each head i.e. I-E-I-E-E-I-E-I. The co-located exhaust valves in the two centre combustion chambers resulted in a "hot spot" making the heads prone to warping or cracking, especially in performance versions of the engine. For the fuel-injected 5000i version introduced in the 1988 VN Commodore, the cylinder heads were redesigned to a repeated I-E design (a similar layout was previously utilised for the HSV VL Group A SV) for all combustion chambers, delivering better heat distribution and thus greater reliability.[2][7]

Depending upon the application, induction was either carburettor or fuel-injection (multi-point or sequential, depending on the year). For the 1986 VL Commodore, the engine was modified to run on unleaded fuel which carried forth to all subsequent models.[2][4][7][8][9]

Initially offered in 4.1 and 5.0 L; 252.8 and 307.8 cu in (4,142 and 5,044 cc) versions, the engines were intended to be offered as part of the 1968 Holden HK range, but the project ran behind schedule and instead became part of the 1969 HT model range. In the HT, the Holden V8 sold alongside the 350-cubic-inch (5.7 L) Chevrolet Small-Block engine until 1974 with the introduction of the HJ series.[10]

5.0 L; 307.8 cu in (5,044 cc) V8

The V8 engine also appeared from 1971 in the Statesman range of large size luxury cars which Holden established as a separate marque, replacing the Holden badged Brougham. In 1974, both the 253 and 308 engines were added to the Torana range for the first time in the LH series (after an aborted attempt by Holden Dealer Team boss Harry Firth to introduce the V8 to the smaller LJ Torana range in 1972 which was stopped by the Supercar scare). The engines were also offered on the LX model range introduced in 1976, but not the final UC range which appeared in 1978.

Both engine capacities were offered on the first VB Commodores which appeared in 1978. The 253 version was not available in the VK Commodore range, released in 1984, but continued in Holden WB commercials until their cessation in late 1984. In 1985, the special editions modified by Holden and their official after-market tuner, Peter Brock's HDT Special Vehicles, began introducing the 5.0 L; 304.3 cu in (4,987 cc) version of the engine, created to slip underneath the 5,000 cc (305 cu in) engine capacity cut-off in Group A touring car regulations, allowing Commodore competitors to run at a lower competition weight. This slight shrinking of the traditional Holden 308 saw the Group A Commodore's racing weight drop from 1,400 to 1,325 kg (3,086 to 2,921 lb). Due to the complex Group A regulations, this also allowed the racing cars to run bigger wheels and tyres without any drop in power. Indeed, the VK Commodore SS Group A was one of the fastest cars in the world of Group A racing when it hit the tracks in 1986.

HDT Special Vehicles also offered a more powerful version of the engine enlarged to 5.6 L; 344.4 cu in (5,643 cc) in some of its VL models between 1986 and 1988, including the controversial Calais Director. This engine, making as much as 231 kW (310 hp), was an expensive option, particularly once Holden severed ties with HDT in February 1987, which drastically increased the prices of all HDT models, and consequently very few of the 5.6-litre motors were made.

Fuel injection replaced the carburettors initially on the VL Commodore SS Group A SV, again with Group A touring car racing in mind, this car produced by Holden's new performance vehicle partner Holden Special Vehicles (HSV) in partnership with British-based Tom Walkinshaw Racing (TWR). While Group A disappeared after the VN model range, the fuel injected 5.0-litre; 304.3-cubic-inch (4,987 cc) engine was offered in Commodores until the VS III Commodore utility in 2000, although there were no longer V8 VS III utilities available for sale during the latter part of 2000.

HSV vehicles featured a variety of more powerful versions of the 5.0-litre, which were also available on regular V8 Holdens as part of the SV Enhanced package. Additionally, from 1994 with the VR series, a 5.7-litre; 349.8-cubic-inch (5,733 cc) "stroker" was standard on the HSV GTS and optional on the HSV Senator, and later on the Statesman/Caprice-based Grange from that model's introduction in 1996.

• Holden straight-six motor