AMONGST sporting enthusiasts a four-cylinder engine is nearly always popular. There is a certain feeling of power which is quite different from the smooth surge of a "six." Many therefore welcome the tendency, particularly in evidence among this season's models, for increased, production of " big fours."

One of the most notable of these new " big fours" is the 16 h.p. Riley, the engine of which has a bore and stroke of 430.5 x 120 mm., and a capacity of 2,443 ,c.c. An advantage of the four-cylinder engine is its short overall length, and this good-sized power unit is mounted in a chassis with wheelbase Oft. 8 in., and track 4 ft. 3 in.

I myself have owned several Riley models, and was particularly pleased when Bob Porter, well known to many competition drivers, and a member of Messrs. Boon and Porter Ltd., the Riley' distributors of Castelnau, Barnes, S.W.13, offered me a test run in his own "big four" Riley Kestrel saloon.

The car is of the type which makes an enthusiast exclaim at once "If only it had an open body" (at present, unfortunately, there are no open models listed). However, it was pouring with rain when we set out to try the Riley's paces, and one was therefore able to appreciate the benefit of a roof.

Comfortable coachwork has always been a teat ure of Rileys, and the Kestrel saloon, with its sloping rear panels, is well shaped to make the most of the performance. Incident ally, however much an enthusiast likes an open body, there is little doubt that a properly shaped saloon is quite as fast as, if not faster than, a corresponding open tourer, at any rate with the screen up. The Riley has an "overdrive " gearbox, with three ordinary ratios, and a high top gear which engages itself automatically at speeds over about 40 m.p.h., if the foot is lifted momentarily from the

throttle. Coming down, third gear, or "traffic top," similarly engages itself at about 35 m.p.h. These, at any rate, are the speeds at which the overdrive operates on Bob Porter's car, but I understand that there are slight differences on individual cars according to the adjustment. The overdrive top is as high as 8.97 to 1, and with 5.25 x18 in. tyres this gives a most satisfactory cruising speed of between 70 and 80 m.p.h., if conditions permit. The only "snag," though not all will agree that it is a "snag," is that in

order to have the overdrive working one must have a freewheel on the other gears.

As soon as the overdrive comes in the drive is locked, and one has the resistance of the engine on the over-run to assist steadiness. Freewheel enthusiasts will say that this is a most admirable arrangement, and so it is. Every man to his taste. It is also possible on the Riley, it should be noted, to lock the freewheel, and in that case one has an ordinary three-speed gearbox, with which one changes gear in the normal manner. The ratios are 14.3 to 1 first,

8.25 to 1 second, and 5.5 to 1 third, or "traffic top."

With the overdrive engaged, we were cruising down the Kingston By-Pass at about 50 m.p.h., and I asked Bob what one did now if one wanted to change down without slowing to 35 m.p.h. to let the automatic third come in.

" That's easy" he said. "You just change down as you would on an ordinary box, and then you are in overdrive second. The ratio on that is 6.15 to 1, and if you really take the revs, up you can do about. 65 on it." Much intrigued, I did as he said, accelerating the engine as for a normal change down. On the overdrive second, as on the high top, one still has the fixed wheel, and though in practice one does not, I should say, make use of it very much in preference to the automatic third, this

extra gear is most useful for acceleration purposes, as when passing other cars. Actually, it is seen, the Riley has five forward gears.

"What speeds can you do on the gears ?" I asked.

"About 28 m.p.h. on first, and about 43 m.p.h. on ordinary second" said Bob. "It depends,:of course, on how high you let the revs. go. Then you can do nearly 80 on third. In overdrive top I have had 98 m.p.h. on the speedo. This has been checked roughly, but we will test it again when we get to Brooklands." The 98 m.p.h. was done on the fiat, but with a downhill approach, and in favourable conditions. The other way, on the same stretch, and with another downhill approach, not quite so fairourable, a speed of 94 m.p.h. was attained, so I was told, and the car has also done 97 m.p.h. with four up I One may as well interpolate here that subsequent careful checks by stopwatch at Brooklands showed that the speedo meter was as nearly accurate as possible at 60 m.p.h., while at a timed 90 m.p.h. the instrument showed 93 m.p.h. The error is thus negligible, and only slight subtractions need be made from the readings quoted above—that is, if we can take Bob's word for it I

There seems no reason to doubt his veracity, as borne out by the performance of the car at Brooklands. Speeds on favourable stretches of road, with the car well warmed up by a long journey, are frequently better than those obtained by an ordinary car on the track. On this occasion there was no wind whatsoever to help the car, and it was still raining hard, while great sheets of water covered the surface in places. The best timed speed for a quartermile worked out at exactly 90 m.p.h., and of several other timed runs in different

places round the circuit, the worst was 86.54 m.p.h. The car was fitted with very mild touring plugs—the compression ratio is only 6.1 to 1—and when this latter speed was recorded, towards the end of the test, I fancy that they were finding life at Brooklands rather strenuous. No pinking, however, was heard at any time.

Having on occasions been with Bob to a number of speed events, I knew that he was something of an expert in rapid gear changes, and for the acceleration figures he took the wheel, and demonstrated just how quickly a lever can be moved from one position to another. What the clutch thought about it I don't know, but certainly some fine times were recorded.

to 30 m.p.h., 6 secs. ; to 40 m.p.h., 9/ secs. ; to 50 m.p.h., 13 secs. ; to 60 m.p.h., 181 sees.; to 70 m.p.h., 251 secs. ; to 80 m.p.h., 511 secs. The big gap in the times between 70 and 80 m.p.h. was caused by the change into the high 8.97 to 1 overdrive. This

change itself cannot be speeded up, as one has to wait for the mechanism to synchronise itself, and moreover with so high a gear one cannot expect a fierce pickup at the top end of the scale. All the same, even on this high gear the Riley is by no means sluggish, and, unlike the overdrive on certain American cars, it is a gear meant to be used when attaining maximum speeds. 5,000 r.p.m. would be about 105 m.p.h..

These times and speeds, it should be noted, were attained on a privately owned car, and not, as is usual with MOTOR SPORT'S official road tests, on a works machine. Whether the figures compare with those of a works car I cannot say, but Porter assures me that his car, while carefully maintained, is quite standard and has not been tuned in any way. Not everyone knows that Rileys were pioneers of the wire wheel, for which they took out a patent as long ago as 1907. The "big four" does not have knock

off wheels, for an interesting reason. A particular point has always been made of a good steering lock for Riley models, and the "big four" is no exception, having a turning circle of well under 40 ft.

. This is achieved by a narrow springbase at the front, and in consequence of this, in order to reduce moments causing the possibility of wheel tramp, the weight of each wheel and hub has been kept as near in. to the axle centre as possible. Thus, instead of the heavy knock-off hub caps at the axle extremities, the car is fitted with " dished " " magna-type " wheels, with a stud fixing. The effect is certainly excellent. The car held the wet track at high speed in impeccable style, and the steering at all speeds was remarkably good. In. considering the weights at each. end of the axle, which play an important part in a steering layout, one must also take into account the exceptionally large brake drums. The brakes are of Girling type,

and were applied hard on the wet concrete at about 60 m.p.h. The car pulled up very rapidly and perfectly straight. Bob Porter is a well known official on M.C.C. events, and was acting as "official car" preceding the competitors in the recent Land's End Trial. He told me

that, with four up and ordinary -tyres at normal pressures, the Riley climbed all

the hills easily except Hustyn. Here wheelspin was experienced, but at a second attempt with tyre pressures lowered-as most actual competitors with ordinary tyres would have done in the first place— no mistake was made.

The Roost was climbed at 26 m.p.h. in first gear right over the "hump."

First gear, it will be remembered, is only 14.3 to 1. On this run, with four up and luggage, and much use of the gears, 800 miles were covered, and the petrol consumption worked out at 20.1 m.p.g. The 16 h.p. Riley in general feels a very firm and solid car. The driving position

gives a good view, and the seat backs are high enough and at the right angle to support the whole of the back. A telescopic steering wheel is provided, for drivers of varying heights. Instruments include a separate rev.-counter and clock as well as a speedometer, and the fuel gauge will also, by pressure of a button, register the amount of oil in the sump. The Kestrel saloon costs £415.