Minor Changes - Page 2
Unlike some telescopic damper and disc brake conversions for the Minor, the Series IV system is a carefully thought out and integrated package which brings the car's handling up to modern day standards. Indeed, during the development of the system, Geoff and Chris met some of the ex-British Leyland design engineers who had worked on both the Minor and Marina.
According to Chris, they were delighted at what he was doing and revealed that they had been developing just such an update for the Minor before its replacement by the Marina meant that the ideas were incorporated into the new car instead. And during the 1990 Morris Minor Nationals show, honorary guest Jack Daniels, one of the original design engineers for the Minor, congratulated Chris on his work.
For many years, car designers had employed a system of soft front and hard rear suspension which resulted in a reasonable handling and comfort compromise. Geoff and Chris drew on more recent suspension theory which dictates that the front of the car, with the heavy engine mounted over the axle line, should be more firmly sprung and damped than the rear. Thus the Series IV car uses very firm adjustable front telescopic dampers sourced from the Bedford CF van.
The front suspension is lowered, but no anti-roll bar is fitted as the damper rates and suspension settings have been developed to a degree where it is considered unnecessary.
At the rear, softer, Five-leaf springs replace the Traveller's seven-leaf type (five-leaf springs are retained on saloons), while Escort RS1600 adjustable rear telescopic dampers are located outboard to allow maximum damping action.
Countering the Minor's tendency to twist or 'wind up' the rear springs on acceleration, resulting in axle tramp, the re-engineered Marina rear axle is positively located with radius arms running from brackets on top of the axle to brackets welded next to the forward spring hangers, where the floorpan is strongest. The arms are angled outwards, which allows the axle to move up and down in its normal arc but prevents it twisting and moving from side to side.
As for braking, the 9 3/4in diameter Marina front discs are matched by Bin Marina drums at the rear, providing a system that is both powerful and well-balanced. Servo assistance is available but not essential.
The Minor's underfloor
master cylinder is retained, but to prevent the residual line pressure required by the original drum brakes, the cup valve is carefully modified. Some conversions recommend that the valve is simply discarded, but this can lead to difficulties in bleeding the brakes.
The use of Marina hubs front and rear allows 13in Marina wheels shod with 155-section radial tyres to be fitted, which slightly lower the car's centre of gravity and improve the handling further still.
With handling and braking power improved to the point where a Series IV Minor could put many later cars to shame, the conversion provides a sound base for uprating the car's performance: Chris Street's Minor currently boasts a fully blueprinted 1380cc A-series engine which produces 98bhp. This drives through a Midget gearbox to give a top speed of around 115mph.
For owners who do not fancy the Marina rear axle and wheels, the company offers a Classic Handling System which uses a Minor axle re-engineered in the same way as the Marina one to take the radius arms and telescopic dampers (which on this system are non adjustable). Should you want to uprate the car to the full Series IV system, all parts are interchangeable. Although not normally sold as part of the Classic Handling kit, it is possible to fit the front disc brake system and use modified hubs which will take the standard Minor wheels.