Riley MPH: ace of diamonds

By Simon Hucknall

| 19 Feb 2025

Classic & Sports Car – Riley MPH: ace of diamonds

In these days of exhaustive market research before a new car is even teased to the public, Riley’s gung-ho approach to pre-war launches would be anathema.

‘Build ’em and they’ll buy ’em’ summarised the company’s marketing philosophy, and perhaps explains why the 1935 Riley MPH you see here is one of only 15 factory examples thought to have been built between 1934 and ’35.

Why the MPH failed commercially we’ll return to, but it remained a superlative, technically advanced and beautiful sports car that could claim bragging rights as a British Alfa Romeo 8C-2300 (works MPHs were second and third overall behind the Chinetti/Étancelin Alfa at Le Mans in 1934).

Riley had pinned its hopes on the technically advanced and beautifully engineered MPH, but the odds for success were stacked against it

It’s no surprise that today genuine factory cars are valued at around £750,000, reflecting their rarity, drivability and near-90mph performance potential.

These qualities had been honed across a decade of racing success prior to the MPH’s introduction.

The Riley Nine had established the firm as a player after its launch in 1926.

Its 1087cc ‘four’ with hemispherical combustion chambers and 90° inclined overhead valves was a rev-happy unit that avoided the complexity of overhead cams by locating its twin camshafts high in the crankcase instead.

Eight Jaeger dials decorate the Riley MPH’s dashboard

It was so well resolved that it formed the basis of not only the later MPH’s six-cylinder engine, but also almost every Riley engine until 1957, long after the Nuffield corporation had taken control.

The Nine’s competition roll-call was impressive and would have bolstered Riley’s fortunes in the Depression era of the late ’20s and early ’30s.

Works Brooklands Nines were first in class at the prestigious Ards TT between 1929 and ’31, followed by an outright win in 1932.

But MD Victor Riley’s desire to push the company upmarket led to the introduction of the Brooklands Six as a sporting road car and more powerful racer.

The Riley MPH’s beetleback rear is a work of art

With its 12hp, 1½-litre ‘six’ – essentially the Nine’s engine with two extra cylinders, but still eligible for the under-1500cc class – there was no doubting the improvement in the Six’s performance.

But it was less wieldy than the Nine and retained that model’s six-year-old basic design, which was starting to look rather passé.

Worse still, MG was snapping at Riley’s heels with cheaper, smaller and more agile alternatives that better chimed with post-Depression buyers.

The Riley MPH’s Duplex-Hartford adjustable shock absorbers provide great control

Riley responded quickly to the Six’s lacklustre reception.

It radically shortened the wheelbase from 9ft to 8ft 1½in and developed a chassis that ran above the front axle, then tapered down to nestle under the rear axle, allowing the car to sit low.

Semi-elliptic springs appeared all round, controlled by Duplex-Hartford shock absorbers, while the 15in aluminium brake drums were actuated by Riley’s ‘Continuous Cable’ system.

Gone was the Nine/Six’s tapered rear body, replaced by a shorter, rounded design.

‘The 15in aluminium brake drums were actuated by Riley’s “Continuous Cable” system’

Riley entered four of these new works cars at the 1933 Ards TT and, despite early problems with the brakes meaning three failed to qualify, CR Whitcroft managed a first in class in the remaining car and eighth overall in the race.

On a roll, Riley then entered two ‘mystery’ works cars in the following year’s RAC Rally, sporting stylish aluminium bodies more akin to those from an Italian carrozzeria than a Coventry factory.

Those in the know recognised them as the TT cars with more exotic-looking bodies.

Shortly after, in May 1934, The Autocar revealed that the cars were, in fact, examples of Riley’s new sporting model, the ‘MPH Six’.

The Riley MPH is impressively agile for a 90-year-old classic car

The first production MPHs rolled out of the factory in the summer of 1934.

Riley offered three versions of the Nine-derived ‘six’ for the rakish MPH from launch: a 1459cc 12hp; a 1633cc 14hp; and a 1726cc 15hp.

Presented as ‘a British car of the highest quality which is in every way suitable for everyday use’, the MPH was little changed from the previous year’s TT racers, save its bodywork.

The brake drums were pressed steel, not aluminium, and there was the option of a four-speed preselector ENV gearbox – as in ‘our’ car – to replace the manual crash ’box.

The Riley MPH’s ENV preselector gearbox is effective and easy to use

Drive was delivered from either transmission through a torque-tube-enclosed propshaft to the rear wheels, with 87.13mph achievable in top at a maximum 5500rpm – an extraordinary speed for a mid-’30s sports car.

The Autocar was among the first to review the MPH, concluding: ‘To the open-air-loving motorist with sporting tendencies, this new Riley MPH should prove singularly attractive.’

Gushing praise, though, was not enough to engender the MPH to buyers.

Pricing was its greatest bugbear: at £550, it was hugely expensive and out of kilter with its rivals.

Lucas ‘King of the Road’ badge on the Riley MPH’s sidelight pod

Cars such as MG’s six-cylinder NB Magnette represented a more off-the-shelf choice versus the bespoke quality of the MPH, but it was almost as fast, more practical and cost in excess of £200 less.

The Riley also suffered from a small cockpit and almost no luggage space, with the area beneath its pert rear body taken up by the fuel tank and spare wheel.

Then there was its Imp sibling, which undoubtedly stole thunder from the MPH.

The Imp was sold concurrently and was in design terms a near facsimile of its more powerful sibling.

‘There’s a rich seam of torque that’s ideal for this track, but the engine’s willingness to rev is too tempting to ignore’

Fitted with the Nine’s 1087cc ‘four’, it lacked the MPH’s outright performance (Riley claimed a 70mph top end), but was lighter and, crucially, cost just £325.

The MPH was doomed from the start, which explains why only 15 or so (estimates vary, due to each one being built to order) were produced, including two prototypes.

The example with us today is one of the best-documented factory-built MPHs remaining.

Chassis 44T 2278 – originally registered as a ‘14.29hp black Riley Saloon’ – received its Rutland number FP 2831 on 16 February 1935, before being delivered to its first owner, a Mr John Cecil Noel of Oakham.

The Riley MPH’s chassis plate; this is one of just 15 or so built

Noel was clearly a Riley enthusiast, having already owned a Monaco and a Nine Falcon; he was an accomplished driver, too, finishing 11th at Le Mans the previous year driving an Aston Martin International.

Noel sold ‘FP’ in 1937 (tragically, he was killed in action during WW2) and the following owner, Victor Auckland, bought it from Oakham dealer Dale & Pearce the same year.

Auckland used the car through the war years, even applying a chequerboard marking to its rump to make it more visible during blackouts.

The Riley MPH’s painted wire wheels shroud its steel brake drums

It was then sold to the aptly named Peter Riley, an occasional BMC works driver who repainted the car burgundy but only kept it briefly.

In 1948 FP caught the eye of South African Denzil Penny in Gurney Nutting’s showroom in Hanover Square, London.

Penny paid £550 – what FP would have cost new in 1935 – and, after a road trip to Scotland in appalling weather, returned to his native country, taking the Riley MPH with him.

The Riley MPH’s handbrake sits just aft of the gearlever

FP’s time in South Africa was full of highs and lows. The Riley was re-registered CA 74190 and campaigned in local club races.

In 1959 Penny sold the car to Edward Wilson, a 19-year-old student, for £250.

Wilson undertook a partial rebuild himself, funding it through work as a part-time taxi driver in Cape Town.

By sheer coincidence, one of Wilson’s fares was Victor Riley’s widow, Dorothy Champney, visiting the country on a world tour.

The Riley MPH’s high-geared steering demands forceful inputs, but grip is impressive

Wilson was so overwhelmed by the meeting that he took her to see his partially rebuilt MPH and offered her a ride in it – which she politely declined.

After Wilson sold this Riley MPH to its subsequent custodian, Harry Gormley, it fell into disrepair and was poorly stored for almost three decades.

When Gormley died in 1992, Riley enthusiast Rodney Green from White River, SA, purchased the car from Gormley’s estate and took on the by then mammoth task of bringing the Riley back to its former glory.

The large four-spoke Bluemel’s steering wheel dominates the Riley’s snug cabin

Green had to replace many missing parts, such as the radiator and the unique three-plunger oil pump, but before he had completed the work the car caught the interest of Essex-based Riley specialist Peter Lee, who persuaded Green to part with it.

Returning the MPH to the UK in 1998 – its first time ‘home’ for 50 years – Lee continued the restoration, which revealed that the car’s original 1726cc motor had been bored out from 62mm to 64mm and fitted with a Laystall crankshaft and ERA conrods – presumably work carried out during its time in SA.

What’s more intriguing is that the Riley’s original ENV preselector ’box, which had been stripped, was revealed to be a race-spec, close-ratio unit, with roller bearings throughout.

The Riley MPH’s free-revving ‘six’ exhales via artfully snaking manifolds

Other original deviations from the standard MPH included two separate, forward-facing SU fuel pumps fitted to its front bulkhead, a Bluemel’s steering wheel and brackets enabling aeroscreens to be mounted on its windscreen uprights as draught deflectors.

FP 2831 (its original number by then reinstated) also sported 36 bonnet louvres, instead of 37 as on all other MPHs.

Today, this Riley MPH is owned and enjoyed by marque specialist Blue Diamond’s David Parry.

Its minder today, David’s business partner John Lomas, admits that the frequently used car is not concours – although it was resprayed four years ago and appeared at the London Concours in 2021 as part of the Queen’s 95th-anniversary display.

Deft body control belies the Riley MPH’s advancing years

For me, the Riley MPH is one of the prettiest and most captivating pre-war car designs to gaze at.

From its close-set Lucas headlights and long, low bonnet to the graceful sweep of its arches towards the handsome beetleback rear, the MPH is a work of art – and a quality-engineered one at that.

Lift the bonnet and the straight-six is mounted low in the chassis.

On the nearside, two elegantly curved three-branch exhaust manifolds shroud the engine block, with its finned crankcase and sump.

The Riley MPH’s close-set Lucas headlights frame the grille

On the other side, twin SU HS4 1¼in sidedraught carburettors sit behind a large Scintilla distributor, and in front of that is a modern electric radiator fan (the Riley ‘six’ runs quite hot).

The ensemble is beautifully laid out, as you’d expect from a manufacturer charging such an ambitious price.

The Riley MPH is small, though. My 5ft 7in frame would likely have been about average in pre-war times, but entering the snug cabin still requires some gymnastics before you’re sitting (very close) behind the large Bluemel’s wheel.

Eight Jaeger dials cover the dash, with the 6000rpm tacho and 120mph speedo dominating your view.

The Riley MPH’s engine is fed by twin 1¼in SU carburettors

An ignition advance/retard lever and lighting control sit on opposite sides of the steering-wheel hub; just behind it, an inch or so down the column, is the quadrant and lever for the Wilson-patented ENV preselector ’box.

Ignition on, push the starter and the Riley’s vocal little ‘six’ bursts to life.

A regular crash gearbox from this era generally requires plenty of skill and finesse to master, but the MPH’s preselector is simplicity itself.

It’s an epicyclic ’box with a set of planetary gears and clutches transmitting drive from the engine to the rear axle.

‘Gushing praise was not enough to engender the Riley MPH to buyers. Pricing was its greatest bugbear’

An engagement pedal takes the place of a clutch, but it is only used conventionally to pull away or as you draw to a halt; at other times, a quick dip of the pedal is all that’s required to engage one of the four forward gears that you’ve selected in advance via the quadrant’s lever (as long as engine speed exceeds 850rpm).

A drive on Bicester Heritage’s short but technical track proves how effective the system is, with advance selection of gears leaving you free to focus on the steering, and a mere jab of the left pedal needed to facilitate a super-quick and clean gearchange; it is in effect a pre-war version of today’s dual-clutch automatic transmissions – and it’s almost as responsive.

But the trick gearbox is only a bit-part player in the Riley MPH’s impressive repertoire.

The Riley’s speedo reads to 120mph; the MPH could hit 87mph, which was impressive in the 1930s

On track, the car feels decently potent, helped by having relatively short gearing (around 17mph per 1000rpm in top).

There’s a rich seam of torque from 2500-3500rpm that’s ideal for the cut and thrust of this track, but the engine’s willingness to rev is too tempting to ignore – along with the cultured bark from its single exhaust.

You feel as if you’re heaving the Riley MPH through bends, due to both your proximity to the large wheel necessitating an arms-out attack, and the amount of heft required turning into corners thanks to the relatively high-geared set-up.

But you’re rewarded with ample grip from the skinny front tyres and a rear end that breaks away progressively and controllably as you up the pace.

The elegantly sculpted but understated rear end helps define the Riley MPH’s compact aesthetic, but a near-absence of storage space was a blow to practicality

Out on fast B-roads the ride is firm, but body control is superb, as is the Riley MPH’s braking performance.

You really have to keep reminding yourself that this is a 90-year-old motor car as you press on along these sinuous roads, frequently clipping 60mph with ease.

On our return to Blue Diamond’s workshop, John suggests that, for many, a Riley Imp matches the MPH in so many ways, and is lighter, more drivable and more affordable – and, objectively, I’m sure he’s right.

You could also argue that the MPH was a white elephant: the wrong car at the wrong time.

But it remains a snapshot of Victor Riley’s determination to launch a pinnacle model in its class that would raise the bar above all others.

Today, its outright pace, sheer rarity and six-cylinder cachet have helped it achieve just that.

Images: Max Edleston

Thanks to: Blue Diamond Riley Services; The Riley Cars Archive Heritage Trust; Robin Cameron’s book, The Riley MPH

Factfile

Riley MPH

Sold/number built 1934-’35/c15
Construction pressed-steel chassis, underslung at rear, aluminium body
Engine all-iron, ohv 1726cc straight-six, twin 1¼in SU HS4 carburettors and magneto ignition
Max power 56bhp @ 4800rpm
Max torque n/a
Transmission four-speed ENV preselector, RWD
Suspension: front radius rods rear live axle; semi-elliptic leaf springs, Duplex-Hartford dampers f/r
Steering Riley ‘frictionless’ worm and wheel
Brakes drums
Length 12ft (3657mm)
Width 4ft 9in (1447mm)
Height 3ft 6in (1066mm)
Wheelbase 8ft 1¼in (2463mm)
Weight 2019lb (916kg)
Mpg 22-24 (est)
0-60mph n/a
Top speed 87mph
Price new £550
Price now £750,000*