One to Buy: ex-works 1957 AC Ace Bristol Le Mans
Launched at the London Motor Show in October 1953, the Ace was AC’s highly anticipated replacement for their ageing 2-Litre range.
Production of the John Tojeiro-designed machine got underway in May 1954 and the Ace quickly earned a reputation as a useful competition car despite its rather pedestrian 100bhp straight six engine which had been imported from the outgoing model.
The AC engine was subsequently replaced from January 1956 when Bristol’s BMW-derived motor came on stream. In its most potent 100D2 form, the Bristol engine produced 128bhp which transformed the Ace into a serious performance car.
One Ace that started life with an AC engine and subsequently got the Bristol transplant in period was chassis AE205 which will be going under the hammer at Bonhams’ Monterey auction on August 18th.
Having started life as a works demonstrator, AC subsequently elected elected to make AE205 their works entry for the 1957 Le Mans 24 Hours. The upgrade programme that followed was all encompassing; a tuned 100D2 Bristol engine was fitted along with a long-range fuel tank, front disc brakes and a modified low drag body. The interior fixtures and fittings also came in for significant attention too.
Ken Rudd (who had been tasked with undertaking the conversion) and Peter Bolton went on to finish tenth overall at la Sarthe which was good enough for second in class behind the Equipe Nationale Belge Ferrari 500 TRC which was a purpose-nuilt sports racer.
Chassis AE205 departed for the US in late 1957 where it continued to race successfully and, since 1963, has been in the hands of just one careful owner.
Today the car is offered in superb condition following a recent restoration.
Reprinted below is Bonhams’ description for this most significant AC Ace:
Chassis no. AE205 (see text)
Engine no. 100D2 786D
The ex-Ken Rudd, AC Works, 1957 24 of Hours LeMans Entry – 2nd in class, 10th overall
Extensively documented history
Single owner since 1963
Recently completed, concours award winning restoration
THE CAR OFFERED
"Of them all, the Ace was the truest sports car: it could be used for daily commuting or for high-speed long-distance touring, but it could also be driven to a race meeting, campaigned with distinction, and driven home again - even if that race was the Le Mans 24 Hours." - AC Heritage, Simon Taylor & Peter Burn.
This stunning Ace is certainly among the most storied examples of the model. Originally built as an AC Ace Works demonstrator with AC engine as chassis AE205, it was subsequently prepared by Ken Rudd as an AC Bristol factory entry in the 1957 LeMans 24 Hour race. For the race, Rudd modified or improved just about every element of the car.
Starting under the hood, to improve performance over the Ace engined powerplant, Rudd replaced the Ace engine, Moss gearbox, and standard differential with a race prepared Bristol 100D2 engine – number 768D – with 9.5:1 compression ratio and a high-performance camshaft, a Bristol gearbox with close ratios on upper 3 gears, and a low ratio differential.
After the engine refitting, the nameplates on the firewall and body were revised to "BE205" with a riveted plate to the factory stamp. Carburetor jetting was set for high-speed driving, and the acceleration enricheners were removed from the Solex carbs to reduce fuel consumption. Air straighteners (air chutes) were added on the carburetor inlets to prevent inlet air separation. In front of the air straighteners, a semicircular intake baffle was added in order to more equalize the pressure field on the three in-line carbs. An electric fuel pump was added in the boot leading to a fuel filter in the engine compartment and the front end of the fuel manifold. The back of the fuel manifold was fed by the standard mechanical fuel pump.
To increase endurance, the fuel tank was enlarged into the trunk area to give 24 imperial gallons (doubling the stock capacity). Refueling of the tank was carried out from inside the trunk using a large diameter, 3.5-inch, Aston Martin filler cap on top of the tank. The standard AC fuel filler pipe opening in the rear wing was covered up with a contoured cap to reduce drag and to satisfy LeMans requirements prohibiting non-functional body openings. The fuel level sender unit was modified to provide accurate fill level indication for the taller tank. The engine electrical system was also beefed up with two high voltage coils (one as spare) and a dual point distributor. An additional fuse box was added on the firewall for separate fusing of lighting.
The exhaust manifold was a 6-to-2-to-1 configuration for scavenging efficiency. It fed a large dimeter exhaust pipe with outlet just ahead of rear wheel. The engine sump had oil slosh baffles added to prevent oil surge. Two breather pipes were added to the rocker covers, replacing the standard breather on the sump, and an oil cooler was added ahead of radiator. Because of the LeMans penalty for adding oil externally, a 2.9-quart oil reservoir tank was added on the firewall and connected by hose to the sump top plate for oil top-up if indicated by a dipstick reading or low oil pressure. This oil feed valve was controlled from the cockpit with a left side control cable.
All that extra get up and go was tempered by replacing front drum brakes with Girling front disc brakes using calipers from Triumph TR3s and custom made discs—making this car first AC to use disc brakes. Dual hydraulic fluid reservoirs, one for brakes and one for clutch, provided added safety while larger 16-inch wire wheels replaced the original 15-inch wire rims.
Beyond the massive fortifying of the mechanical aspects of the Ace, the car was sent to the AC Works in Thames Ditton for extensive body modifications. The most noticeable change to the body is the smaller low drag nose to reduce aerodynamic drag and to reduce the air flow inherent in the standard Ace nose at high speeds. Additional drag reduction was achieved with an undertray (bellypan). This undertray had an opening on the right side for the exhaust manifold and exhaust pipe assembly. To allow cooling air to exit the enclosed engine compartment, vents were added to the sides of the body forward of the doors.
Additionally, an intake air duct was added in the bonnet to direct cooler ram air to the carburetors. Finally, a low profile, reduced height full width Plexiglas windscreen and side curtains were fitted as well—adhering to the LeMans rules that required full width windscreens. To facilitate rapid engine inspection and maintenance, quick-release hood latches were added. It is worth noting that many of these body design details were subsequently incorporated into the design of the AC Cobra that famously carried the mantle of the Ace into history.
A novel, non-functional addition to the car's body at the LeMans race were four small, lateral strakes added on the after edges of the wing/fender openings. These were required to meet the specified minimum body width for LeMans.
The body was painted an AC Works Green that is similar to Aston Martin's Racing Green. The similar hued Aston team was not thrilled with this, so Ken Rudd added the distinguishing "AC" marking on the nose.
Given the all-day and night nature of the race—and varying weather conditions, the lighting systems were also improved. Fog lights were mounted at the sides of the grille, headlight bulbs were replaced with LeMans-qualified units with yellow bulbs, and, for the race, caps were placed on the front marker lights. The AC rear license light was replaced with a Lucas Combined brake light/license light on the rear of the trunk lid (as used on the Triumph TR3). Small marker lights were added for number illumination on the right-side door and on the boot lid.
In the cabin, unlike standard ACs, the fascia was aluminum painted in the body color with an open glove box. The instrument panel layout was slightly adjusted to facilitate rapid review of operating status of the car during the race. An oil temperature gauge was added and the fuel gauge was moved to be directly in view of the driver. The instrument bezels were painted flat black over the original chrome and on the right side of the panel, a stalk was added for actuating a headlight high beam flasher for passing on track. The steering wheel had the horn button and turn signal lever removed and replaced with an aluminum insert. The cockpit also included a dipping rear view mirror to reduce headlight glare and a Halda Speed Pilot in the glove box to facilitate race management. The glove box also included the requisite fire extinguisher.
The seats were fashioned from aluminum with air vents in the back. The foot pedal area was supplemented with foot guides to the left of the clutch and to the right of the accelerator as well as a footrest on the left side. A cooling air duct brought air from the nose air intake area to the driver's foot box, with its air-metering flapper valve controlled by an additional cable rod on the dash. There was no heater installed, so the exhaust pipe below the driver's seat area provided the only cockpit heat for winter driving—which would not have been an issue during LeMans anyhow. Lastly, there was the aforementioned additional control cable on the left transmission tunnel used to operate the emergency oil supply tank.
Derek Hurlock drove the car to France followed by Ken Rudd with FS 50, a prototype Ace Bristol, for use as a practice car. Ken Rudd and Peter Bolton drove the car in the 1957 LeMans 24 Hour Race and finished 10th overall and 2nd in the 2-liter class, only 55 miles behind the last remaining Ferrari 500TR. The Ace completed 2348 miles (3780 km) at an average speed 97.9mph. The car further compiled the fastest lap ever for an AC Bristol on the LeMans old circuit, at 104.5mph.
Not long after its success at Circuit de la Sarthe, the car was sold at the end of 1957 to Dr. Richard A. Milo of Pennsylvania. Dr. Milo painted the body white with blue stripes, added a large full-width roll-over bar, and replaced the full-width windscreen with a small Brooklands-style racing windscreen. Dr. Milo bought the car to race in SCCA E-Production class, but the SCCA scrutineers reclassified the car as E-Modified due to the minor changes made for LeMans. He raced it at Watkins Glen and Road America coming second in class at the 1958 Watkins Glen Grand Prix and first in class at the 1959 Watkins Glen Classic.
John Snyder III acquired the car from Dr. Milo and raced it in SCCA races for several years. After moderate success, John moved on to a much faster Lister-Corvette, and the AC was again put up for sale.
The current owner bought the car in April 1963 and drove it on the street for years as a daily driver commuting from Washington, D.C. to Baltimore while working at Westinghouse Aerospace on the Apollo Program and various space and radar projects. The car was ultra reliable, with no issues except for a half shaft key shearing due to looseness in the differential gears (an issue that has since be fixed), and the lack of a heater making for blustery winter drives.
In one of the more unusual tasks asked of the AC, it was used as a rowing shell carrier. The car, with its wide roll-over bar and an added bipod attached to front bumper brackets, was pressed into service to carry a 34-foot, pair-oared racing shell for a win in the 1965 Middle States Regatta in Philadelphia—likely making it the only AC, or Le Mans racer, to haul a boat.
The car was subsequently retired to the owner's basement in 1972. Over subsequent years, the car's engine and all mechanical and electrical components were rebuilt. A painstaking full restoration of the body and equipment to its LeMans configuration was carried out in 2019-2021 by British car specialist Mike Gassman of Gassman Automotive in Waynesboro, Virginia. Photos and records detail the work completed.
The restoration objective was to restore the car's body and running equipment to as close to its 1957 race status as possible. One of the more challenging tasks on the body was to reproduce the 1957 nose inlet shape using photos from LeMans—the original nose had been slightly reformed by Dr. Milo.
Though the body color had been changed to white with blue stripes in 1958, the original color was still present on the fascia/dashboard and was used to duplicate the original color. In a nod to its post-LeMans history, the original scrutineering sticker from the 1958 Watkins Glen Grand Prix was carefully preserved in situ in the glove box.
Since restoration, the car has been displayed at East Coast Concours d'Elegance events at the Greenbrier in White Sulphur Springs, West Virginia, St Michaels in Easton, Maryland, and Hilton Head in South Carolina. Awards included best in the AC class at Hilton Head and Historically Significant Sports Car at Greenbriar.
Now ready for its first new owner in over sixty years, it is a stunning opportunity to acquire a race-proven machine that foretold the future of the Ace. Beautifully finished, it would be equally at home on the track as it would on the concours field, to say nothing of the many fabulous events worldwide for which it would provide swift entry.
