UBR 135 —
1958 AC Aceca-Bristol
One of the more completely documented Aceca-Bristols in circulation: a matching-numbers 1958 car, one of just 169 built with Bristol's six-cylinder engine, carrying an unbroken six-decade history — and one unusual detail under the bonnet that sets it apart from any standard car.
Specification
A life in six decades
- 1958
Left the AC works at Thames Ditton in October 1958, specified from new with disc brakes and overdrive, and registered UBR 135. It was supplied by KN Rudd — Ken Rudd, the man who pioneered the Bristol-engined AC and won the 1956 Production Sports Car Championship — to a Mr Alexander of Henley, and maintained in its early life by AC Cars itself.
- 1966
After a spell in Durham, sold in Newcastle-upon-Tyne to Richard Barnett, then a final-year Bristol University student, who would keep the car for a remarkable 41 years and build the comprehensive file of period invoices that still accompanies it.
- 1973/74–2007
A full overhaul was begun, but Barnett — a driving force behind the regeneration of Britain's inland waterways — set the project aside for the canals. From a canal-side cottage near Birmingham's Gas Street Basin, the Aceca was laid up on blocks for 34 years.
- 2007
Bought by a fellow canal-and-AC enthusiast and restorer, who completed a thorough, exceptional rebuild.
- The engine
The Bristol engine was first rebuilt to standard specification but, found uninspiring, was entrusted to Steve Stanton of Stanton Motorsport, who rebuilt it with Cosworth pistons and a fast-road camshaft to give around 140 bhp at 5,500 rpm.
- 2011–2015
Acquired for extensive European touring: roughly 7,000 reliable miles across Spain and France, with around £17,000 invested in maintenance — including about £8,500 with Stanton Motorsport and a new competition clutch — and further work by Bristol specialists Spencer Lane-Jones.
- 2017
A further £7,000-plus on refurbishing all road wheels, uprated rear springs, bumpers, a new radio and modified seat runners.
- Today
After custodians in Sussex and Cheshire, the car remains in careful private ownership, recently recommissioned: a full service, the triple Solex carburettors sonic-cleaned and rebuilt, and tuning.
The heart of the matter: a Stanton-built Bristol six
The Bristol 100-series engine was already the making of the Aceca — a BMW-328-derived, cross-pushrod six that lifted the car from pleasant to genuinely quick. What makes UBR 135 unusual is that its engine was taken a step further. Rebuilt to standard first and found wanting, it was handed to Steve Stanton, who fitted Cosworth pistons and a fast-road camshaft with matching valve work. The result — around 140 bhp — sits comfortably above the roughly 105 to 130 bhp of standard road tune, giving a period-correct car a genuinely modern turn of pace while keeping the Bristol's flexible, torquey character. It is a rare thing: a matching-numbers Aceca-Bristol with a documented, sympathetically uprated engine.
Why it matters
Matching numbers, an unbroken and well-evidenced history from 1958, and an engine that is both period-correct and quietly exceptional — that combination is what separates a good Aceca-Bristol from a memorable one. Of the 328 Acecas built, only 169 carried the Bristol engine; UBR 135 is one of them, and one of the better-documented survivors.
About the author
An independent classic-car enthusiast in North Yorkshire with decades of hands-on experience on British classics — including the AC Aceca — writing the single-model reference he always wished existed. Read the full bio.