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.
; 179 Cu Inch .
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
Muir campaigned the S4 again in 1965 and up against the mighty V8 Mustang of Bob Jane and the Lotus powered Cortina of Ian Geoghegan the lights changed and what followed was 10 laps of pure motor racing . Before completing the first lap Muir had to pit to fix a loose bonnet clip . Rejoining the race he worked his way back to 4 th . By the second last lap the mighty mustang that had led all the way was slowing with a broken fan belt . Muir surged past the lotus powered Cortina and the mighty Mini to be side by side with the V8 mustang at the line but Ian Geoghegan took the trophy with the mustang .
The official results were