Chrysler made plans to conquer the Indy 500 in 1953 with the hemi Firepower V8, but the scheme worked a little too well.

In February of 1952, the Contest Board of the American Automobile Association, the sanctioning body for the Indianapolis 500 and big-league open-wheel racing, made it known that it was considering a new displacement limit for production-based engines at Indy: 5.5 liters, or 336 cubic inches. The hope, as always, was to improve competition and encourage more entries.

At the time, the maximum allowable displacement at Indy was 4.5 liters (274.6 CID) for nornally aspirated engines and 3.0 liters (183 CID) for supercharged engines, based on the 1938 Formule Internationale, and for years the race was dominated by 270 CID, four-cylinder Offenhauser engines. This potential displacement break for factory-based engines was exciting news for the Chrysler Corporation, as its 331 CID Firepower hemi V8 introduced the year before was the hottest thing going.

Chrysler Engineering got right to work, giving the project the official name A311. By June 12, 1952 the engine above was running on the dyno, sporting a handmade intake manifold, Hilborn-style fuel injection, and the designation A311-EX1. From the intake stacks we can see that Chrysler was already experimenting with tuned-length induction systems (see our feature on Chrysler Ram Induction here).

Naturally, the modifications didn’t end there, as special cylinder-head castings with larger intake and exhaust ports were tooled up. (Stock vs. race intake side at top shown above, exhaust side below.) The upgrades also included larger valves, domed pistons with a 12.5:1 compression ratio, lightweight piston pins, a dry-sump oil system, and a racing cam with roller lifters.

Still, the A311 retained a number of production pieces. Chrysler Corporation president David A. Wallace was able to boast in Popular Mechanics that the connecting rods, rocker arms, piston rings, crankshaft, and crank bearings were all factory components. The 3.8125-in bore, 3.625-in stroke, and 331.06 cubic-inch displacement were maintained as well. On the dyno, the A311 V8 produced a little more than 400 hp at 5,2000 rpm, and it was rumored that 447 hp was achieved at one point. At the time, the factory Firepower V8 was rated at 180 hp at 4,000 rpm.

To fit under the hood of an Indianapolis racer, a laydown fuel injection manifold was developed, still using tuned-length intake stacks (above left). Chrysler arranged with Roger Wolcott, an Indianapolis Chrysler dealer and seasoned team owner, to mount an A311 V8 in a new Kurtis-Kraft KK500 chassis. (A second car was later built.) At the time, the KK500s were the most advanced racers on the speedway scene, and they are widely regarded as the first true Indy roadsters. However, in Wolcott’s car the hemi V8 was located on the chassis centerline rather than offset to the left as in the classic Offy fashion.

In an October 1952 test session arranged by Firestone at the Indianapolis Motor Speedway, the Kurtis-Chrysler was driven by journeymen Joe Sostillo and Joe James for three days and more than 500 miles. The instant speed they found was shocking: The A311 averaged 134 mph and Sostillo ran laps at 137 mph, exceeding that year’s  pole speed. In its first on-track test, the hemi V8’s performance was more than sufficient to win the Indy 500.

And that’s what put paid to the entire program. From the Contest Board’s perspective, it would be foolish to give a 62 cubic-inch advantage to an engine with such obvious  potential. And far from encouraging more entries, the A311 could obsolete the Offy and put many of the existing teams out of business. When the 1953 rules were finalized, there was no special displacement limit for production engines at Indianapolis. The Chrysler could race, but at the same 274 cubic inches as everyone else. Wolcott ran a destroked 270 CID hemi at Indy in May of 1953, but it failed to get up to speed.