DEVELOPMENT
and
HISTORY

of AC's post-war 2 Litre Saloon.
Page 3

Early Production



Production cars started to appear from October 1947. After about 10 cars or so, the complex bonnet opening system was dropped and replaced by a centrally hinged two piece bonnet. Each bonnet half opens through an angle of about 130 degrees or so, which is fine provided it is not a windy day! Several other features either failed to make it into production, or else were phased out after the first few cars. These were the original seat designs. More conventional front seats, completely separate, and with a little more lateral support. The original sunburst pattern rear seat was replaced by a more traditional ribbed design, with a nicely concealed folding central arm-rest. The gearbox dip-stick was concealed under the (now larger) transmission tunnel, but with an access hatch. The accelerator pedal was changed to a simpler and smaller design and the cable control for it replaced by a linkage.



A few of the earliest cars had a double-layer of alloy for the bulkhead around the footwells, sandwiching soundproofing fibre-board. The inner layer of alloy was soon discontinued. The radiator cowl was originally made of aluminium alloy, but this changed to brass.

Externally, the hub-caps were changed to a simple part-spherical shape with AC emblem in the centre (similar to the hub-caps that Triumph used at that time). Trafficators were moved to a position just behind the side windows. A conventional starting handle was supplied, clipped inside the boot (as were tyre hand-pump and jack). A pivoted section of the radiator grill unclipped to permit access for starting handle to engine. The front bumper was moved a little lower and had different mountings (I think the original was one large curved bracket, then replaced by two).

A short way into production, the rear wheel spats were dropped. During 1948, a drop-head body style was introduced, although officially launched for the 1949 model year. This was for export only, but most were right-hand drive. This was a superb looking car, described by the "Motor Industry" magazine simply as "Dream Car from Ditton"! It looked stylish with hood either up or down. Rearward visibility was extremely limited with the hood erected, and not much better with it folded! Some of these export cars featured extra bonnet louvres, doubtless for hotter climates. Many early ones also had 16 inch wheels, in place of the usual (at that time) 17 inch rims. The very first drop-head had fixed side windows, cabriolet style. Sadly, very few were built and production of them ceased in 1950, apart from an experimental car later on.







Alternative designs of windscreen were tried including square corners to the central pillar. By late 1948 the windscreen had changed to the more familiar chrome-plated frame mounting. At least two versions were produced, with either a flange on its rear side for fixing to the body frame, or several brass angle brackets. I'm not sure which came first, but the brass angle brackets were fragile, having apparently been bent by hand. Another hidden detail change, probably during 1949, was the quarter-light window mechanism. Originally, this used a screw-thread and lever mechanism, but this changed to a worm and gear system.



During 1948, an alternative drop-head version was in development. Buckland bodyworks created a much modified open body for the AC. It had a single piece fold flat windscreen, thicker, more rounded door tops, the front wing line continued to the rear wings, and the hood was fully concealed when folded. Interior and boot were much altered too. Later ones had a cut-away door top, and in some cases alternative styles of rear wings. During 1948/49, several chassis were supplied to other companies (sometimes with wings). A few of these ended up as estate vehicles. Out of the few photos I've seen, 2 cars looked very ungainly, while the other (more attractive) was like an enlarged Morris Traveller.



Road Tests

One has to try and make allowance for the very diplomatic approach of magazine-employed road testers to criticising cars. Even so, it is easy to spot real enthusiasm for any particular merits of the car in question. "The Autocar" tested an AC 2 Litre Saloon for its 29th July 1949 issue. It was stated that ride was firm, but less so than expected for leaf springs. It was also reported that the car was stable and benefited from the high-geared steering. It performed like the pre-war sports models, but with a more comfortable ride and more powerful brakes. The excellent forward vision from the driver's seat, with the high front wings in full view (the widest part of this car), also received praise. Braking power was good, but required a large physical effort from the driver's leg. The high quality interior was fully appreciated by the tester, as was the simple layout of dashboard controls.



This road test suggested that the twin-tone horns should have been louder and the head-lamps brighter. Also the sun-visors would have been more effective if wider (I can vouch for that last point!). The weight of the production cars was quoted as 26cwt (1320kg). Performance figures for this road test were: 0 to 50mph (0 to 80km/h) in 16.0 seconds. 0 to 60mph (0 to 97km/h) in 22.6 seconds. Top speed 83mph (134km/h). Maximum power 74bhp (55kW) at 4500rpm. Maximum engine torque 95 lbs-ft (130Nm). Fuel consumption 22 to 24mpg (8 to 8.5 km/litre).

This very same car was then road tested by "The Motor" magazine for their 21st September 1949 issue. Acceleration figures were better, and this is explained by the different final drive ratio. AC had been phasing in a change from a Moss back axle (gear ratio 4.625:1) to an ENV axle (ratio 4.55:1). This test car had evidently changed back to the Moss axle between its two performance tests. Performance figures were: 0 to 50mph (0 to 80km/h) in 14.1 seconds. 0 to 60mph (0 to 97km/h) in 19.9 seconds. Top speed 80.4mph (129km/h). Fuel consumption 23mpg (8.1 km/litre). In gear acceleration figures included 30 to 50mph (48 to 80km/h) in 8.9 seconds in 3rd gear.

It should be noted, that acceleration figures timed for speed changes (e.g. 0 to 60mph) are misleading. It is the time to cover a distance that provides a valid comparison between cars. A standing start kilometre or quarter mile are more reliable ways to compare acceleration. But the 0 to 60mph figures have become so well established, that manufacturers have concentrated on improving this timing over all others - even to the point of compromising important points such as tyre size or gear ratios, just to get 60mph without an extra gear change. For the AC, "The Motor" achieved 22.0 seconds standing quarter mile. Over the following decades, standing quarter mile times of cars generally, have come down by around 25%. Meanwhile, 0-60 times dropped to less than half!

"The Motor" provided more detailed performance figures. Fuel consumption at constant speeds in top gear: 50mph (80km/h) returned 24.0mpg (8.5 km/litre) and at 70mph (113km/h) it was 18.0mpg (6.4 km/litre). Maximum gradients for each gear were recorded: Top gear 1 in 13.5; 3rd gear 1 in 9.25; 2nd gear 1 in 6.5. Braking distance from 30mph (48km/h) was an impressive 31.5ft (9.6m), requiring a pedal force of 160lbs (712N or 73kg).

Similar comments about the ride and handling appeared in both tests. Ride was moderately firm, but car was very stable and held the road well. One criticism by "The Motor" was the amount of warm air entering the car. Warm air can pass around the edges of the bulkhead and the front floor panels.



One recurring feature of road tests and articles of the day, was enthusiasm for the styling. AC had managed to produce a more practical and comfortable car, while retaining both performance and sleek looks - which is what they had set out to do!

<< Page 2 ****** Page 4 >>
HOME-PAGE

Sitemap





Website started 29th December 2006