Vintage SCI Review: 1957 Austin-Healey 100-6 – The Big Healey Gets a Six

Although most commonly known as the Austin-Healey 3000, that version of the “Big Healey” (to differentiate it from the Sprite) was the third major variant of the series, built from 1959 to 1967. Probably the second best known is the original, the 100 (often now referred to as the 100-4), built from 1953 to 1956. In between, there was the 100-6, from 1956-1959, the subject of this SCI test.

The biggest change was that the rather hoary old 2660 cc four, which originated in the Austin A90 Atlantic, was replaced with a 2639 cc inline six, in this case the BMC C-Series engine, which originated at Morris. That was not done primarily to improve performance, but to improve smoothness and refinement. The 100-6 also got a 2″ wheelbase stretch, two kiddie seats in back, and a number of other refinements. The 200lbs lighter 100-4 was still faster up to 60mph, but above that speed the six’s twelve additional horsepower made it faster.


There was also a new top, improved braking and heating, and other small changes, that added up; it “makes it feel like an entirely different car”.  The 100-4 had been primarily targeted to the amateur sports car racer, and its success there was considerable. But the sports car boom of the ’50s was expanding, and especially in America, where there was also a priority on certain creature comforts.


Clearly the changes were made to make it more competitive to the Jaguar XK-140 but at a significantly lower price. The 100-6 started at $3095, whereas the XK-140 started at $3645 for the roadster and $4045 for the 2+2 convertible.



One of the downsides of the BMC C-Series engine was that its intake manifold was a log-type affair cast integral to the head. That limited breathing some, as the somewhat modest 102 hp output attests. But that would soon be changed, with a new head that upped power to 117 hp, as in the engine shown in the red car above.


Once again, the 0-60 time of 11.6 seconds may sound very modest by today’s standards, but it was right in the same ballpark as most of the popular sports cars of the time. The A-H 3000, with its larger 2.9 L version of the C-Series, eventually reached 150 hp.

As with all of these British sports cars that had solid rear axles, the rear end easily skittering, especially on bumpy pavement in a curve. That’s why the AC Ace and the Porsche, with their fully independent rear suspension were so highly respected.