Ford Mark IV
In 1966, Ford achieved top honors in the field of international endurance racing. Despite growing costs, Ford decided to continue development of the GT40 for the 1967 season. This campaign was already the largest and most expensive American assault on the predominantly European series.
While the 427-powered Mark II cars proved a remarkable success in 1966, their hefty weight motivated Roy Lunn, a senior designer at Ford, to seek out drastically new designs. Two promising projects had already been in development and both incorporated aluminum in their chassis design. The first such car was the X1 prototype built by McLaren Racing Limited. This car featured an aluminum version of the GT40 tub and raced quite successfully, winning at Sebring in 1966. The second project, called the J car, was a much more experimental than the X1. This fresh approach appealed to Lunn, who convinced Ford to move forward with the project.
The J Cars
It was the technique of using honeycomb-sandwiched aluminum which motivated the J car. This technique used half inch honeycomb aluminum panels which had to be bonded together. The first J car would use this honeycomb aluminum to form a central tub chassis similar to the GT40's. The final specification for the car adhered to the Appendix J regulations for race car construction.
Since Ford Advanced Vehicles had been sold off, the J Car was produced by Fords subsidiary Kar Kraft. Ed Hull headed construction of the experimental J-Car program with assistance from the Brunswick Aircraft Corporation.
The first J-car, called J-1, was completed in March of 1966. It's chassis, which weighed 86 lbs, supported the fiberglass body and 427 engine. J-1 made its first public appearance at the LeMans trails that year. It weighted 2660 lbs which was nearly on target with the 300 lb weight reduction Ford was looking for. At such a weight it was not surprising that the J-Car took the fastest time at the trials. Unfortunately, the J-Car was sidelined for the rest of the 1966 season to help the GT40 Mark II's effort.
After the 1966 1-2-3 Le Mans win, Ford decided to invest more money in the J-Car program. A second car, made up to Can Am specification, was made to help sort out the aluminum honeycomb chassis. Unfortunately, this car was completely destroyed during testing in an accident which claimed the life of Ken Miles. Driver error was never considered.
After a weak performance at Daytona, where transmission problems plagued six Mark IIs, Ford reluctantly continued the J-Car program in preparation for Ferrari's 330 P4. They worked on chassis J-3 and J-4 in preparation for Sebring. During this time, Roy Lunn, Chuck Mountain and Phil Remmington worked on the J-cars extensively. They created a new body for the chassis which incorporated a longer front nose, a Can Am style tail section and a new roof line to accept a rear window. During this transformation the J-Cars officially became known as the GT40 Mark IV.
While the 427-powered Mark II cars proved a remarkable success in 1966, their hefty weight motivated Roy Lunn, a senior designer at Ford, to seek out drastically new designs. Two promising projects had already been in development and both incorporated aluminum in their chassis design. The first such car was the X1 prototype built by McLaren Racing Limited. This car featured an aluminum version of the GT40 tub and raced quite successfully, winning at Sebring in 1966. The second project, called the J car, was a much more experimental than the X1. This fresh approach appealed to Lunn, who convinced Ford to move forward with the project.
The J Cars
It was the technique of using honeycomb-sandwiched aluminum which motivated the J car. This technique used half inch honeycomb aluminum panels which had to be bonded together. The first J car would use this honeycomb aluminum to form a central tub chassis similar to the GT40's. The final specification for the car adhered to the Appendix J regulations for race car construction.
Since Ford Advanced Vehicles had been sold off, the J Car was produced by Fords subsidiary Kar Kraft. Ed Hull headed construction of the experimental J-Car program with assistance from the Brunswick Aircraft Corporation.
The first J-car, called J-1, was completed in March of 1966. It's chassis, which weighed 86 lbs, supported the fiberglass body and 427 engine. J-1 made its first public appearance at the LeMans trails that year. It weighted 2660 lbs which was nearly on target with the 300 lb weight reduction Ford was looking for. At such a weight it was not surprising that the J-Car took the fastest time at the trials. Unfortunately, the J-Car was sidelined for the rest of the 1966 season to help the GT40 Mark II's effort.
After the 1966 1-2-3 Le Mans win, Ford decided to invest more money in the J-Car program. A second car, made up to Can Am specification, was made to help sort out the aluminum honeycomb chassis. Unfortunately, this car was completely destroyed during testing in an accident which claimed the life of Ken Miles. Driver error was never considered.
After a weak performance at Daytona, where transmission problems plagued six Mark IIs, Ford reluctantly continued the J-Car program in preparation for Ferrari's 330 P4. They worked on chassis J-3 and J-4 in preparation for Sebring. During this time, Roy Lunn, Chuck Mountain and Phil Remmington worked on the J-cars extensively. They created a new body for the chassis which incorporated a longer front nose, a Can Am style tail section and a new roof line to accept a rear window. During this transformation the J-Cars officially became known as the GT40 Mark IV.
14 years ago
