30.d. 1973 Holden Premier HQ 253ci V8 Sedan
2014 Gore Aussie Muscle Mania Car Show (12-4-14)
Holden 253 V8 engine:
The Holden 253 V8 engine is an 8 cylinder cast iron v8 engine that was equipped with cast iron cylinder heads, a common pin crankshaft , over head valves with a hydraulic camshaft & non adjustable rocker gear. The Holden V8 was produced from 1969 to 2000 in Australia by General Motors Holden. The Holden V8 engine was used in many model Holdens from the Kingswood, Monaro, Premier, Statesman, Torana, Commodore plus used in the Holden commercial range of ute & panel vans as well as the Holden 1 tonner tray top.
The Holden V8 253/308 is believed to be a close relative to the Pontiac family of engines rather than the Chevrolet V8 283, 307, 327, 350 or 400 small block engines and there are no interchangeable parts from the Aussie V8 & the USA Chev engine.
It is also believed that the Holden 253 & 308 engines were designed for the RHD market as the starter motor is on the left hand side or passenger side of the vehicle as opposed to the American left hand drive cars.The oil pump on a Holden V8 engine is mounted on the passenger side front of the engine and also has the spin on style oil filter to screws directly to the oil pump.
The Holden 253 / 4.2 V8 uses a common pin crankshaft with a 3.0625 stroke with 3.625 diameter pistons
The conrods are 5.625″ long the 253 and 308 use the same conrod bearings on both the big ends, main bearings & conrods with the only major difference being the 253 uses a 5/16 conrod nut & bolts and the 308 uses a 3/8 conrod nut & bolts.
It is believed to be that General Motors Holden started the 253 cu V8 development in 1964 with the success of the inline 6 cylinder engine Holden needed a more powerful power plant to keep its market share as Ford already had its Windsor V8 engine well under way. General motors required a compact size, light weight engine with an increased displacement over the six cylinder engine.
The first Australian V8 for passenger car use had a displacement of 253 cu / 4.146 litres, a compression ratio of 9:1, and a maximum horsepower 185, with 262 lb. ft. A complete Holden 253 v8 engine from fan to flywheel including accessories like distributor, alternator & starter motor is 460 lb., The 253 Holden V8 is only 80 lb. heavier than the Holden six cylinder red motor.
The development of the Holden 253 cu. in. V8 started in 1964 when the GMH Engineering Department began a serious study for the design of the next Holden engine. The V8 configuration was chosen because it met all the requirements for compact size and light weight. It gave increased displacement over the six cylinder range without loss of smoothness and the potential for future displacement and output increase.
Following design studies which showed that GMH could satisfactorily combine the best features from world practice suitable for Holden in Australia, in a package, smaller and lighter than then equivalent displacement engines already in production, six experimental engines were built for evaluation in 1966.
A full production program was then undertaken, aiming at the provision of a smooth, powerful, durable and economic engine.The result was the first Australian V8 for volume passenger car use. The engine had a displacement of 253 cu. in., 4.146 litres, a compression ratio of 9:1, a maximum horsepower 185, and a maximum torque of 262 lb. ft. Dry weight of the complete engine assembly from fan to flywheel and with all accessories including the alternator and starter was 460 lb., only 80 lb. heavier than the light weight six cylinder engine. The overall width was only 22 inches.
The V8 was tested and proved in extensive dynamometer and road durability testing at the GMH technical centre and proving ground. Its development was aided by its inclusion as the power unit for the GMH research car the Holden Hurricane. The cylinder heads incorporated cross flow porting and large valves in a shallow wedge shaped combustion chamber for good breathing, conducive to a high specific output. The cylinder block of 3.625 cylinder bore was a compact iron casting and together with the cylinder heads, was cast in GMH foundries.
The nodular iron crankshaft of 3.06 stroke was extremely rigid due to the short stroke and large diameter main and connecting rod journals. Optimum engine balance was obtained by close weight control of pistons, connecting rods etc., and by individual balance of crankshaft, flywheel and clutch, followed by a dynamic balance determined on the completed engine assembly when running under its own power.
Piston and piston ring specifications were developed to provide quietness, long life and low oil consumption. The valve train represented the first use in Australian manufacture of a design incorporating stable cylindrical aluminium rocker arm pivots in conjunction with pressed sheet metal rocker arms. As in 6 cylinder engines, GMH manufactured hydraulic lifters were used, incorporating a long plunger travel to allow the use of the non-adjustable rocker supports. Camshaft drive was by roller chain, with neoprene damper on drive side.
From 1971 the 253 was fitted to the Statesman and, in 1974, the engines were added to the new larger LH Torana range and was offered as well on the LX model range, but not the final UC range which appeared in 1978. Both engine capacities were offered on the first Commodores which appeared in 1978. The 253 ci version was dropped in 1984 and was not offered in the VK model range. At the same time the special editions modified by Holden's official after-market tuner, Holden Dealer Team began introducing the 304ci (4.9 litre) version of the engine, created to slip underneath the 5000 cc engine capacity cut-off in Group A touring car regulations, allowing Commodore competitors to run at a lower competition weight.
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 replacement after-market tuner Holden Special Vehicles (HSV). While Group A disappeared after the VN Commodore, the fuel injected 304 engine was offered in Commodores right up until the VS III Commodore utility.