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Little Digger Chassis

H Modified


Engine: Crosley

Builder: Chalmers Hall

Current Owner: lost?

Listed in Joe Puckett's book Big Men in Little Cars (which is now out of print).


"Sports car racing was really getting widespread in California in 1958, an nowhere was the competition among Specials builders more fierce than in the H Mod class. To pull down a H Mod Champiopnship title, you had to be a good driver and a very good builder.

The winner of the 1958 SCCA Pacific Coast Region H Modified championship was a man maned Chalmers Hall, who hailed from Phoenix, Arizona. Hall piloted a little Crosley-powered Special called the Little Digger, and he was just about unbeatable in it.

According to the Sptember 1959 issues of Sports Car Graphics, 'In the past two years, the Little Digger ... has been entered in an even dozen main events. It failed to finish twice and took 10 firsts in class. Never has any other Class H car beaten it across the finish line in a main event!'

That's about as good as it gets. Hall who was not a professional welder, taught himself well enough to fabricate a ladder-type chassis of 1.25-inch 4130 chrome-moly tubing, with seven main cross members. No information is available on the body, but it appears to have been a home-made aluminum shell.

The engine was a much-modified Crosley which Hall dubbed the Aerojet, with stock bore and stroke, special one-of-a-kind Clay Smith camshaft, hard-chromed steel crank, special lightweight tappets and modified ports, topped off by a Braje valve cover. Carburetion was supplied by a 39DC03 dual-throat sidedraft Weber mounted on a fabricated manifold, ignition by a Scintilla Vertex magneto and exhaust was routed through a custom system patterned after the one on Ken Miles' 'Flying Shingle'. A modified MG TC transmission was controled by a Morris clutch pressure plate. The rear end was a stock Crosley Hotshot unit, utilizing a torque tube system and a 5.17:1 final drive ratio.

The 84-inch-wheelbase chassis used semi-elliptic springs at the front and rear, with Columbus shock absorbers. A stock Crosley steering unit, except for a lengthened pitman arm, gave 1.5 turns lock to lock. Brakes were Goodyear Hawley spot discs, as available optionally on the Crosley Hotshot.

The 750-pound result, with weight distribution of 48 percent front/52 percent rear (with driver) would run the standing quarter-mile at 84.6 mph, and top out at 114 mph.

Hall, quoted in SCG, described the purpose of building this car as 'To beat all the other Class H Specials.' Obviously, he was a man of his word."2

Race Entry

Chalmers Hall is listed on the Entry List for the 14th Palm Springs Road Race (Under 1500cc Modified), Palm Springs on December 4-5, 1958. Other H Mod entries included Gounis-Crosley Special, Ferry-Renault (2), Halliday Special, Miller, DB Panhard, Crosley-Special.

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"SCCA regional race
at Palm Springs
on November 2, 1958"2


PalmSpringsCA_Nov1958_a.jpg (20353 bytes)
In the paddock, also at
Palm Springs, Nov. 19581

1Photo provided by Dave Thielke.

2Article by John Gardner, photo by Bob Tronlone, Vintage Motorsport (March/April 1993), Little Digger, p33. This article was scanned for the Sports Racer Network by Curt Anderson.

Revised: September 06, 2006.

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