Car Construction F2

8 CAR CONSTRUCTION — FORMULA TWO AMENDED MARCH 2015.

Heritage Formula Two stockcar racing reflects the early years of the sport, starting in 1960 when racing for small cars called ‘Junior Tens’ was launched at Tamworth Stadium and ending at the conclusion of the 1972 season prior to the ‘modern era’ of entirely custom built racing cars. The following regulations combine the spirit of the sixties with issues of safety required today.

8.1 Cars permitted for racing are Ford Model Y built between 1932 and 1937. Ford Model CX built in the late thirties. Ford E93A and similar carrying Anglia, Prefect and Popular badges between 1938 and 1948 and Ford’s of the same chassis construction featuring transverse leaf spring suspension built as late as 1959 usually carrying the Popular name badge. Non Ford’s permitted include all Morris 8 and 10 cars built up to 1948 and any other cars by special permission with engines of less than 1200cc original displacement built before 1948. The all-up weight of the car ready to race, but excluding the driver, must not be less than 550kg. Ballast of any kind is not permitted. Body shells do not have to be original to the chassis but we are Heritage F2, so all cars should resemble the F2 cars of the 60s.

8.2 In view of the age of the original donor car through tubes should be welded into the original chassis rails to add strength between front and back bumpers. These can be round steel tube, 2 inch or more diameter, or hollow section structural steel square tube, either 40 or 50mm in size. The wheelbase should be a minimum of 88 inches and a maximum of 94 inches. Bumpers should be not less than four inches in depth, and the height of the bumper centerline from the ground should be sixteen inches, plus or minus one inch. Bumper ends must be rounded and smooth. Bumpers should be approximately the same width as the tyre track front and rear.

 8.3 A roll cage featuring a minimum of four vertical posts, diagonally braced, should be welded to the chassis, to closely follow the contour of the body shell internally. Outside diameter of the tube should be not less than 30mm. with a 3mm wall thickness or 38mm diameter with 2mm wall thickness. The roll cage must feature either a 3mm steel roof plate above the driver’s head or extra roof bars in roll cage material aimed at protecting a driver in case of roll-over. Inch and a half or two inch Weld mesh must be welded to the complete front screen opening. The cage sides must feature side impact bars constructed from minimum 25mm steel tube or box, minimum 2mm wall thickness.

8.4 The body shell should be securely bolted or welded to the chassis if it has been removed to facilitate construction of the roll cage. Body shells do not have to be original to the chassis. Where a fabric roof featured originally, this must be removed and replaced by a sheet of aluminium or steel welded, pop riveted or bolted to cover the entire roof. The measurement of a full height Ford Model Y from chassis top to roof at the B post is 46 inches. The same measurement for a Ford ‘Pop’ is 49 inches. The floor panelling must be complete in the vicinity of the driver.

8.5 A fuel tank of maximum 2 gallons capacity must be fitted within the body shell, secured within a steel cradle/mounting bracket. The tank must feature a metal screw cap and spill proof vent, a none return valve must be fitted. The supply pipe to the engine must feature a cut off tap within easy reach of the driver. The fuel pipe must be metal, with only short rubber connections where there are joints for a fuel tap, fuel pump or carburetors. Fuel used must be as available at filling stations. Lead replacement additives may be used. A secondary firewall must feature around the fuel tank. Fuel tank and battery must not be mounted together.

8.6 The battery must be fitted inside the body shell and must be secured in a steel frame and bolted down. The battery should be covered with rubber or polythene to minimize the chances of spillage if inverted. An isolator switch must be fitted close to the driver in a position he can reach while strapped into the car. It must also be in a position visible to rescue teams if an emergency should occur. The isolator switch must be to the earth side of the battery and must isolate ALL electrics. It is advised that the battery supply to the starter is routed on the opposite side to the fuel line.

8.7 The driver’s seat must be of continuous all metal construction, not ‘rally type’ tubular steel. A separate slip over padded cushion is permitted. The seat may be steel or aluminum. The seat must be bolted or welded to the chassis/through tube construction. It is advised that the seat bottom is bolted down in four places and the seat back in two places. When seated the driver must have a minimum 2 inches headroom against the roof plate.

8.8 A safety harness comprising not less than two shoulder and two lap straps with adjustable straps and quick release buckle must be fitted. The fixing points for the lap straps should be such that the angle of the straps when enclosing the driver approximates 30 —45 degrees to the horizontal. It is advised that the shoulder straps are fixed at a point as close as is practical behind the seat and that the fixing point is clearly below the driver’s shoulders. The end fixings for the harness must be securely bolted to the chassis/through tubes/roll cage construction. Where plate lugs are welded into the frame to fix the harness, these should be minimum 3mm thick steel. The strap width should be 3 inches or metric equivalent. A fifth crutch’ strap must be fitted if the seat is of a reclining type.

8.9 The axles must be of the type fitted to the original donor car. Fords featuring a torque tube driveline must retain this layout. Brakes must work on all wheels. The final drive ratio may be changed to assist gearing and the differential may be locked. Limited slip differentials are not permitted. Wheels and tire sizes may be changed to assist gearing. ‘Banded’ wide rims are not allowed. Rims should not exceed 5.5 inches wide to reflect what was in general use in the sixties. Shock absorbers can be upgraded but adjustable shock absorbers are not permitted. Left foot braking is not permitted. ‘Rose joints’ or spherical bearings must not feature in any part of the suspension.

In 2012 several cars had been built with 100E rear axles and open prop shaft, these cars were in contravention to the rules. At the AGM 2013 in order to maintain numbers of cars on track a special dispensation was made to allow those cars to have Grandfather Rights to retain that layout. A register was drawn up of the relative cars to be retained for future reference. Appendices 1

The above cars must feature a steel hoop around the prop manufactured from 3mm x 25mm steel bar. This is to stop the prop hitting the driver’s seat in the event of failure. Prop-shafts over 18” in length must feature 2 equally-spaced steel hoops and a steel plate under the seat. The axle must be set central to the chassis, i.e. back plate to chassis is the same dimension on both sides of the car.

No other 100E axles will be permitted for introduction after 2013 unless they are fitted with torque tube drive and transverse spring.

8.10 Tires should reflect those generally used in the sixties. These may be crossply or radial but should not be of excessive width. As a guide, a 5.5-inch ‘footprint’ was the widest used on F2 stock cars in the sixties. Modern equivalents of crossply tires like the Avon 7.3 used in BriSCA F2 is not permitted, but the earlier Avon 6.9 in original sixties compound is allowed. Old racing tires and modern Hoosier type tires are also considered unsuitable. If other competitors consider a tire unfair and if there are no visible sidewall markings to certify its manufacture as legal within this regulation, it must be removed. Radial tires cannot be less than 80 series aspect ratio. Tire softening chemicals are NOT permitted.

8.11 The power unit must be of the type originally associated with the chassis or manufacturer, as previously indicated, except that Fords later 100E side valve engine may be fitted to earlier E93A or Model Y chassis. The power unit may be modified internally but not externally i.e. not OHV conversions on side valve engines. No supercharging is permitted, no fuel injection is permitted, but any type of carburetor avalible in the 60’s may be fitted, along with free flow exhaust systems. Nitrous Oxide injection is not permitted. Electronic ignition is permitted. Only single sparking systems can be used. All forms of Multi Spark Discharge (MSD) electronic ignition and similar types are NOT PERMITTED. Including any electronic ignition type that offers any form of adjustable feature by whatever means, the only ignition advance curve allowed is that which is produced mechanically by balance weights within the distributor. No other systems will be permitted. A complete firewall must feature between the engine bay and the driver. For practical purposes a maximum of 1232cc is advised. This will permit 1172cc Ford engines to be bored 60 thou, oversize. Where a water pump features on the engine, this must be the original mechanical type. An effective silencer must be fitted to the exhaust system and must terminate behind the drivers feet, exhaust gasses must not be deflected upwards which might cause aggravation to other drivers.

8.12 The original steering box may be replaced in the interests of durability. A quick release steering wheel is permitted and encouraged. No rack and pinion steering is permitted unless it was original equipment on the donor car.

8.13 Only one driver per car is permitted per meeting except by specific permission and prior arrangement with the trustees.

8.14 A vote among active drivers has confirmed the view that fiberglass bodies are not in the long-term interest of the sport. It is not intended that this should affect any existing drivers or cars, but could affect new constructions after 2008.

8.15 Drivers of ‘Specials’ and cars with lowered bodies are not permitted to hit full height cars in the corners. This is to reflect the comparative maximum cornering speed of the three types.

8.16 Roof Fin plate official numbering is compulsory and must be painted/ printed in black lettering on a white background, the numbers must be minimum 9” high on both sides of the car. The Fin plate must not exceed 12” high and be of straight panel construction. No aerofoil is permitted.

Appendices 1

Nigel Finnigan    Y Model

James Pratt          Topolino Special

Pete Welland       Y Type

Paul Rokyard       Topolino Special

Martie Page         Y Type (2 Cars)

Graham Bunter    Y Type

Nick Whitney       Farina Special

Jack Bunter           Y Type

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