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Riley Kestrel. . .9h.p.

 Kestrel 9hp + 8/90 here     Kestrel Four Light 12/4+16/4+ Kestrel Sprite  here       Kestrel Six Light 12/6+ 14/6 + 15/6 here  Big Four here

One of the best looking sporty vintage saloons ever made and the most  obviously 'Art Deco' design of any Riley models. It was technically a lowered Monaco with the roof line sculpted downwards and backwards to reach the rear of the boot giving an aerodynamic profile. This was a conscious decision to design a model not easily copied by competitors like MG and to create their own fashion. The initial models had an almost Monaco front end and interior with the addition of pneumatic cushion squabs and a slightly longer  chassis frame to allow the streamlining.. The first 9hp were $308 with the 12/6 at £348 and the 14/6 at £375 so not the cheapest available.
During 1934-5  about 700-800 of the 4-light Kestrels were produced, plus a few Kestrel 'Sprites' although there is no indication with the chassis number. The design  was essentially identical to that  fitted to the larger 12/6  cars, but mounted on the improved chassis with a shorter bonnet. By 1936 the whole 12/4 range was revised and re-launched as  '1½ Litre'. There were numerous improvements to the chassis, but the most obvious alteration  was that the Kestrel had a new 6-light profile.
 RAC Rating 11.9hp All pre-war vehicles have an RAC horsepower rating, which was linked to the Vehicle Excise Duty or VED, aka Road Tax, Car Tax, Tax Disc and Road Fund Licence, and a figure for brake horse power. When the horsepower tax was introduced on 1 January 1910 a formula, known as the RAC Rating, was used to calculate the horsepower . This formula was based on 'applied theory' and derived from basic principles rather than from the results of a bench test. It had three assumptions which never varied: a mean effective cylinder pressure of 90 psi; a mechanical efficiency of 75% and a mean piston speed of 1000 ft/min. hp = ( D2 x n ) / 2.5 where D = the diameter of the cylinder in inches and n = the number of cylinders. The Vehicle Excise Duty payable was: 0 to 6.5hp – 2 guineas (£2.10); <12hp – 3 guineas (£3.15); <16hp – 4 guineas (£4.20); <26hp – 6 guineas (£6.30); <33hp – 8 guineas (£8.40); <40hp – 10 guineas (£10.50); <60hp – 21 guineas (£22.05). The rate was changed to £1per hp on 1 January 1921, encouraging an interest in light cars and effectively limited large engines to luxury cars.
By 1930, engine developments meant that the effective cylinder pressure was 125 psi, and piston speed had doubled. Some manufacturers, such as Rover, started to use a double rating system and designated a car as eg. 10/25, where the 10 was RAC horsepower and 25 was indicated horsepower.  The RAC Rating was used until 1947 and replaced by a flat rate of £10 per year for all cars until recent changes where tax is based upon pollutants.

Engine 4cyl ohv;    Bore 69 ;  Stroke 100; Size 1496 cc; 51bhp at 4800rpm / 55bhp at 5200rpm; Carbs' Zenith, a pair of  Zenith or a pair of SU;  4-speed gearbox with top gear ratio 5.5:1 3rd G/r 7.84:1 2nd G/r 11.64:1 1st G/r 20.09:1 Reverse 25.19:1 Suspension Semi-elliptic springs; Brakes are Girling Mechanical Rod width edge operated shoes 13" drums; Speed 0-50mph 19.2sces Standing Quarter Mile 24.5 secs Max speed 73.6mph unless downhill.  Fuel Consumption 28.3mpg Sizes Wheelbase 9'1"/ 2730mm Tracking 4' /1200mm Length 13'7"/x 4110mm; Width 4'11.5"/1500mm;  Wheels Dunlop centre lock wire 3.0x18; Tyres 4.75x18; Weight 23.5cwt; Fuel Tank 10 galls

Special Series Option Knowledge so far; please add if you know more:-The special series 12/4 features a big valve cylinder head and twin zenith carbs. The “sprite series” cars feature a cross flow cooling system and different oil filter arrangement.   On the early “special series” option additions were more aesthetic rather than mechanical. (Eg sunroof and non standard colours)

1933 Riley Kestrel 9 © CLIFF JONES PHOTOGRAPHY

  Kestrel Chassis codes:-

Chassis number totals after the code indicate the total of that engine/chassis type so includes Falcons,Lincocks  etc but are included as if your car is not within these parameters check as recently many have been sold as 1936 with a 1937 chassis etc Early cars using 60/22Tand 44T used common marking as pre the split into specific model codes

60-> 9 hp Kestrel ie pre chassis code and the same as other early nines (until July 1935)
S66K 1935 9hp Kestrel (from August 1935 numbers between 101-2200 )
44T 1933-4 14/6 Kestrel saloon (from Oct '32 numbers between 101-1300 )
44T 1935-7 15/6 Kestrel saloon (from Oct '34 numbers between 2244-2499 )
46K, 1936 on 12/6 and 15/6 Kestrel saloon ( from July 1935 numbers between 2500-3000)
47K, 1936 on 15/6 Kestrel saloon ( from Oct' 1936 numbers between 3001-3299)
48K 1937 on 15/6 Kestrel saloon ( from Oct' 1937 numbers between 3300 -?????)
49K 1939 on Nuffield Kestrel saloon ( from June 1939 numbers between 1501-1613)
87K 8/90 Kestrel saloon ( from Oct' 1935 shorter wheelbase numbers between 101 -109)
87K 8/90 Kestrel saloon ( from Oct' 1936 longer wheelbase numbers between 201 -211)
22T 1935 four light saloon; 12/4 Narrow track  using Midland Bodies( Oct' 1934 numbers between 101-2199 ) 22T was also used for other models
26K 1936 six light saloon;  Wide  track  using Midland Bodies ( from July 1935 numbers between 2201-5000 )
27K 1937 six light saloon;  Wide  track  using Midland Bodies ( from October 1936 numbers between 5001-7200 )
28K 1938 six light saloon;  Wide  track  using Midland Bodies ( from October 1937 numbers between 7201-7950 'ish)
28KX 1938 six light saloon; += Overdrive gearbox Wide  track  using Midland Bodies ( from July 1935 numbers between 1001-1314)
SS = Sprite engine,   S = Special series engine upgrade 

Media:    Video of a 1934 Kestrel ,     The Art Deco Cars Book click here      Riley Kestrel Specials data click here

Clubs for this model:  The Riley Register,     The Riley Motor Club,    &  those from other countries listed here

1934 Riley 'nine' wheel + dashboard

1934 Riley 'nine' engine in regularly used format

Original Newspaper Articles:-

1937 12/4 Riley Kestrel © CLIFF JONES PHOTOGRAPHY

First car advert showing aerodynamic properties. . .  by Riley

1934 advert to say relevant in 1936 !