S4 : In 1964 G.M.H released the S4 sedan . This was a purpose built vehicle designed for racing at Bathurst. The rules stipulated that for a vehicle to be eligable to race the manufacturer had to produce a certain number of the same vehicle for sale to the general public . I have been unable to verify how many were made . Some say only 5 whilst others say 150 .

Pictured above . This was the Red S4 (Yes its a black and white photo) raced at Bathurst by Brian Muir being chased by the White Jaguar of one Bob Jane ... Easter 1964

The Car : The S4 was basically a standard EH sedan with the following Modifications . (Specs taken from original GMH EH Workshop manual )

Model Identification: EH / 225 M - S.4.

Engine ; 179 Cu Inch .
Modified B.X.V.-2 Stromberg Carburettor : Modified float Chamber which incorporated a lower power jet chamber .
Radiator : The Radiator is the same as fitted to the Automatic model except that the oil cooler pipe has been removed from the lower tank .

Clutch ;
1: The clutch housing is larger with wider spacing of bolt holes for attaching the transmission .
2: The pressure plate assembly has a heavier cover and a new cast pressure plate
3: The driven plate is of a new design with special linings and more heavily dampened .
4: The clutch actuating cylinder body has the flange off-set to the cylinder bore to provide cylinder to transmission case clearance . Owing to the modified clutch housing it has been necessary to revise the exhaust to clutch housing attaching bracket.

Transmission : The synchromesh transmission is basically the same as that fitted to the EJ model except that the transmission case mountings bolt spacing has been increased . In addition the gear shifter crank assembly , the shifter and selector rods have been redesigned to provide adequate operating clearances from the clutch housing . The transmission assembly is identifiable by the suffix S.4 added to the serial number .

Rear Axle : The gear ratio of 3.55:1 is fitted and the gear case is made of Nodular Iron .

Brakes :Brake linings and shoes remain the same as the standard sedan however a change has been made to the Brake Shoe Retracting spring , brake shoe hold down spring and pin assembly. Power Brakes are also standard on the S4 Model

Fuel Tank : The fuel tank capacity has been increased to 12 (imp) gallons by enlarging the lower half of the tank . The fuel gauge tank unit has been revised to suit .

At the Races :

In 1964 Brian Muir arrived at the Mount Panarama track with his new S4 Holden . Up against much improved Cooper mini's , the Ford Cortina GT of Ian Geoghegan and Harry Firth and the big white Jaguar of Bob Jane .

Bob Jane began practice with a time of 2:55.8 and a speed of 140.mph down Con Rod . Brian Muir in the S4 managed a 2:58.9 at 130 MPH . Leo Gioacchino Ford Cortina GT on a 2:58.9 and Harry Firth 's Ford Cortina GT on a 3:02 .

The main race for these cars was a 3 lap race . The race was won by Bob Jane in the big Jag , setting a new lap record of 2:55.9 at 146.34 MPH followed only seconds behind by ...you guessed it ...Brian Muir's S4 Holden .A top speed of 129 MPH and 2:57 despite an overheating problem ! The official results were

Race Results

The official results were

Race Results