Tim Birkin's supercharged 4½ Litre — the most famous Bentley of the vintage era and a Le Mans icon despite never winning outright.
Built against W.O. Bentley's own preference for naturally aspirated engines, the Blower Bentley was conceived by Sir Henry 'Tim' Birkin and financed by the Hon. Dorothy Paget. A Roots-type Amherst Villiers supercharger was fitted ahead of the radiator, raising the 4,398cc four-cylinder's output to around 175 bhp in road trim and over 240 bhp in racing form. Only 55 Blowers were built (50 production cars plus five works racers) to satisfy Le Mans homologation requirements. None ever won at Le Mans, but Birkin's harrying of the Mercedes SSK in 1930 — using up the German car so the works Speed Six could win — created the Blower legend.
The most charismatic of all vintage Bentleys; supercharged engineering, period race history and tiny production numbers combine for permanent collector status.
| Variant | Years | Production | Notes |
|---|---|---|---|
| Blower 4½ Litre (production) | 1929–1931 | 50 | Customer cars built to satisfy homologation; varied coachwork. |
| Birkin Team Cars | 1929–1930 | 5 | Works racing cars; the most valuable of all Blowers. |
For pre-war and vintage cars such as the Bentley 4½ Litre Blower, provenance is paramount. Chassis and engine number matching, period coachbuilder records, factory build sheets where available, continuous ownership documentation, original handbooks and any competition or concours history are the foundation of value. Original supercharger and matching numbers, Vanden Plas team-car style coachwork, verified period race history.
The Villiers blower is the defining feature and the most expensive component to maintain. Confirm rebuild history, drive coupling condition and oil-feed integrity; the supercharger raises stress on bearings and head gasket throughout. A pre-purchase inspection by a recognised marque specialist should include compression and leak-down testing, magneto and ignition checks, chassis straightness and frame survey, axle and steering wear assessment, brake system review (mechanical or hydraulic per period), and an extended road test on varied terrain to expose carburation, cooling and gearbox issues that only emerge under sustained running.
Pre-war coachwork is rarely truly original after a century of use. Establish whether the body is original to the chassis (period photographs, build records, coachbuilder plates), whether it has been re-bodied at any point, and the standard of any restoration. Quality of timber framing, ash health, panel beating and paint depth are all critical. Concealed structural rot, re-bodies presented as original, and 'tribute' cars built on later or unrelated chassis must be priced accordingly.
Verified one of the 55 original supercharged cars with documented period coachwork — not a later W.O.-built 4½ Litre converted to supercharged specification. Birkin works-team provenance is the highest tier. For vintage cars, event eligibility — Mille Miglia, Goodwood Revival, Pebble Beach, VSCC events, Le Mans Classic — can underwrite a substantial proportion of market value. Verify FIA/FIVA papers, period race history where claimed, and the car's standing with the relevant marque registry before purchase.
Regional ranges authored independently — each reflects its local market, not an FX conversion
Vintage cars require disciplined preventive maintenance: lubrication regimes, magneto service, carburettor synchronisation, brake adjustment, and timber and trim conservation. A car used regularly and serviced annually by a specialist will outlast a stored example neglected for decades.
A small number of UK and European specialists handle Blower-specific work; supercharger overhaul is a specialist sub-discipline. Confirm the availability of marque specialists, period-correct fasteners, coachwork trim, instruments and tyres before committing. A car requiring fabricated one-off parts will absorb time and cost that a similar example with active specialist support will not.
Each region quoted in its local currency — independent market readings, not FX conversions
Blower Bentleys are among the most valuable pre-war British cars and the market is essentially supply-constrained. The Bentley factory's recent 'Blower Continuation' programme increased global awareness without diluting original-car values.
| Date | Auction | Car | Mileage | Result |
|---|---|---|---|---|
| 2024-08-16 | Gooding & Co. Pebble Beach | 1929 4½ Litre Blower Tourer (Vanden Plas) | — | $4,840,000 Sold |
Iconic, finite production, irreplaceable history. Original Blowers remain at the very top of the pre-war market.
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Register interestThe valuation figures in this guide are for research purposes only and do not constitute financial or investment advice. See our full disclaimer.
