The Treen-Replica Riley Nines
THE other day we journeyed down to that beautiful part of England which is found near Petworth to inspect the competition Riley Nines which are a speciality of the Amberley Engineering Company.
The production of these special Rileys has been started by John Treen with a view to providing an “1,100” of stark conception and high performance, expressly suited to the requirements of the amateur competition driver. Before the war he ran a Riley Nine modified to “Ulster” specification, and encouraged by the doughty deeds of these cars in all manner of races and speed events, and in particular by the data on Freddie Dixon’s earlier Rileys which a contemporary divulged during hostilities, Treen decided to celebrate the return of peace by racing his own Riley and putting replicas into small-scale production at his Amberley garage.
To reduce cost certain used component are employed after overhaul and a rigid specification is adhered to. Either a “Brooklands” Riley Nine chassis frame or a standard Riley frame downswept behind the engine in a similar way and underslung at the back is employed. This is boxed-in along its entire length and provided with four main tubular crossmembers as well as a tie-rod between front and rear dumb-irons. The wheelbase is 8 ft., the track is unchanged. A special, slightly inclined radiator with its filler beneath the bonnet is fitted, enclosed in a slim cowl. The normal 1/2-elliptic suspension is retained, the springs being reconditioned and flattened, while the front Hartford shock-absorbers are mounted transversely. The wheels and brakes are reconditioned Riley, the former of the stud type and the latter the large-diameter variety. However, the old cable brake operation is replaced by Lockheed hydraulic actuation, the back-plates for the rear brakes being turned through 90 deg. to bring the Lockheed cylinders to the top. The piping is carefully led round the rim of the back-plate to clear the attachments for the cycle mudguards, but at the front these mudguards are rigidly mounted on the chassis. The twin reservoirs for the brake fluid live under the floor by the driver’s feet and the brake linkages are so arranged that approximately 70/30 front-rear braking effort is obtained. The hand brake is a neat little lever outside the very business-like cockpit.
A normal reconditioned Riley back-axle is used with a 5.25 to 1 final-drive ratio and, unless the chassis is a “Brooklands,” the torque tube is reduced in length by 9 in. to avoid splining, a new, lighter propeller shaft being fitted. Steering is by the normal Riley box, reconditioned where necessary.
Naturally, the engine, besides being reconditioned, is taken in hand very thoroughly. Martlet pistons and late-type connecting rods are used, the normal compression-ratio being 10 to 1, although this can be reduced to about 9 to 1 by fitting a thick gasket, if required. The valves are of standard size, the inlet ones being opened by a special Dixon-designed camshaft. No change is made normally to the exhaust camshaft. The 1 7/8 in. two-bearing crankshaft from the Riley “Merlin,” of which a good supply is still available, is used, with Glacier white metal mains and big-ends. The oil-pump outlet is opened up and this gives sufficient increase of oil pressure to necessitate scrapping the standard oil gauge in case it decides to burst, but the sump is standard.
Finding that the Riley Nine normally runs very cool, Treen has so far dispensed with the water pump. Consequently, it has been possible to take the rev.-counter drive from the base of the B.T.H. magneto, but should it be deemed advisable to fit a water pump an alternative drive can be taken from the crankshaft-driven dynamo. At present some beautifully-made Siddeley-Deasy reduction gearboxes of somewhere about the Kaiser War era have been used to drive the rev.-counters, but when supplies dwindle special gearboxes will be made up. Later, too, special Scintilla magnetos will be available.
The carburation system is impressive, consisting as it does of four Amals, their slides lifted by short direct-pull cables from a rod running above them. The slides are shut by a single return-spring of very generous dimensions, limited centrally. The cables are also substantial and an easily synchronised, completely reliable method of actuating these multiple carburetters seems to have been found —and was obviously inspired by Freddie Dixon’s well-tried layout of pre-war days. Fuel is contained in a light, cylindrical 12 – gallon rubber-mounted tank concealed in the tail and fed by air-pressure generated by a hand-pump conveniently located beside the remote gear-lever for actuation by either driver or passenger. Although we should not have recognised it, this hand-pump is a clever adaptation of a Dunlop foot tyre-pump ; air-feed is the most reliable fuel feed of all, and if it has a weak link it is the pump, so Treen has been wise to choose Dunlop for this component. The engine is normally run on “Pool” with the addition of “Octol” anti-knock agent, or on “Octol” racing fuel.
The Riley unit gearbox is naturally retained, but is fitted with a new input shaft, layshaft end gears and third gear pinion made specially by the H.A. Engineering Company, so as to provide gearbox ratios of 1.0, 1.25, 1.74 and 2.6 to 1.
Regarding these Treen Replica Rileys as a whole, they are attractive little cars, their doorless long-tailed bodies in 18-gauge light-alloy being very reminiscent of Freddie Dixon’s first racing Riley which he built for the 1932 T.T. They can be finished in any colour to choice and look what Treen intends them to be —cars built for fast road and competition work and devoid of any unnecessary fittings or equipment that detract from performance. On the near side separate exhaust stubs from each exhaust port run straight into a compact silencer. The dumb-iron cowling improves the neat frontal aspect and the cockpit looks very much “the real thing” with drilled metal flooring, drilled pedals, and racing-type bucket seats. These seats have steel trays, alloy backs, 2 in. sorbo cushions and are upholstered. Aero screens of thick perspex of Treen’s own manufacture and a Derrington quick-action fuel-filler on the tail are part of the equipment. The remotegear control with its long tunnel and tiny lever like those of a “Brooklands” Riley is also made in the works and incorporates a proper reverse-catch. The starter switch and fuel tap are placed on the right of the cockpit by the driver’s elbow, so that he has simply to drop his hand to start the engine or to cut off the fuel in an emergency. The only feature of the car to which we took a mild objection was the rather ugly stream lining of the rear-view mirror. The
(Continued on page 281)