Supercharged o.h.v. Engine and Entirely New Body among the interesting features of Ulster II Model

THE latest addition to the range of Frazer Nash cars is the Ulster II supercharged model, and cars of this type have been entered for the German Grand Prix, the International Alpine Trial and the R.A.C. T.T. race.

The chief novelty, of course, is the supercharged Meadows engine. This is a four, with cylinders 69 x 100 giving a capacity of 1,496 c.c. Two overhead valves per cylinder are fitted, and the rockers, push-rods, and the head itself have been modified to Frazer Nash specification. The pistons are made from the new R.R.53 alloy which has a low coefficient of expansion, and carry three rings. 100 ton steel is used for the H. section connecting rods, and the big ends are bronze, lined with white metal. The crankshaft is of the disc web type, fully balanced, and is carried in three bearings. The supercharger, which incidently is a No. 9 Powerplus, is accommodated on the off side of the engine, and is driven from the crankshaft by a double roller chain, a motor-cycle type shock-absorber sprocket being used at the lower end. The Powerplus has been found to absorb very little power, and blows at 12 lbs. at 3,000 r.p.m. The carburettor is an S.U. mounted below the supercharger, ingeniously arranged so that the piston moves in a horizontal plane, the piston chamber projecting forwards, with the top

feed float chamber at the rear of the instrument. A pressure relief valve on the short induction pipe prevents damage in the event of blow-back.

On the near-side of the engine are mounted the water-pump, which forces water to the rear end of the engine, and the dynamo, with a vertically disposed distributor at the rear end. Two coils are permanently wired up, and a dashboard switch allows a change-over to be made without coming to rest.

Dry sump lubrication is employed, and a two-gallon tank mounted on the dash, in conjunction with an oil filter, should ensure freedom from lubrication trouble. A two-gallon petrol tank is also fitted on the dash, and supplements the 15-gallons carried at the rear. Pressure feed is used, with a reserve tap, and bore tubing and a filter guard against the possibility of fuel stoppage. The dash tanks can be filled through traps in the bonnet.

The engine is expected to give 80 h.p. at 4,000 r.p.m., maximum revs, being over 5,000. The unorthodox Frazer Nash clutch, in which the thrust is not communicated to the engine has been retained, but the driving pegs have been strengthtned. The transmission remains unchanged, the propellor shaft driving a cross shaft by bevel. On the cross shaft are mounted four sprockets, any one of which may be locked to the shaft

by sliding dogs. The back axle carries corresponding sprockets, so that a direct drive by chain is provided on all gears. The cross-shaft sprockets are provided with annular recesses to which oil pipes lead, and centrifugal force brings the oil through holes in the sprockets on to the chain rollers. Double roller chains are used for third and •top gears.

The Ulster II model has gear ratios 3.8, 4.8, 7 and 11.6 to 1, but any of these can be altered at will by changing the axle sprocket, a feature which is not possible with more orthodox transmission systems, but which is a great joy to the competition man. The chassis members are straight throughout, extensions being bolted on at the rear end to carry the tank, stayed by angle irons and steel plates, a construction which gives lightness and strength. A slightly dropped tubular front axle is employed, and back and front brakes have 12 inch drums. Quarter elliptic springing is employed, with Andre shock absorbers back and front, the latter pair being fitted below the front axle and acting as radius rods. The chassis height is easily altered by placing wedges under the springs which allow a ground clearance to be provided suitable for anything from track races to colonial trials. High geared steering is standard and this, to gether with ample toe-in and trail makes driving very pleasant on a long journey. An Ashby steering wheel is fitted, the thin rim of which, covered with a springy should be

quite non-slipping. The lines of the new model are very pleasing. The radiator, which is fitted with a stone-guard, and a lever filler cap, is slightly inclined. The bonnet which slopes slightly upwards towards the rear extends right back to the dash and when opened allows excellent engine accessibility. An outside exhaust pipe is fitted with Brooklands silencer and fishtail as standard equipment, the pipe emerging from the rear end of the bonne t. The scuttle sweeps upwards and provides wind deflectors for driver and passenger, and a flat-folding screen of wire mesh or safety glass is fitted as required. The facia board holds a fine array of instruments, most prominent being the large dial Jaegar speedometer and rev. coun

ter. A switch in front of the passenger allows the spare coil to be brought into use, and he is also provided with a Smith chronograph or stop clock, which be

sides its ordinary timekeeping function allows lap or journey times to be calculated.

One’s impression of the car as a whole is that it combines very successfully good lines and the specification of a roadracing vehicle. Incidentally, it should be mentioned that a metal-panelled version of the Boulogne model, as raced last year, is now available. This is a less expensive car, but when fitted with an unsupercharged Meadows engine, is capable of 85 m.p.h. with full equipment.

The prices are : Ulster II supercharged from £650 and Boulogne II £425 and onwards.