The Ardun Lives
by Rich Boyd - R & C
The history of the Ardun heat-treated cast-aluminum head is one of significant interest in the racing community and more than enthusiastic interest, eventually, from the hot rodding hobby. These unique hemispherical heads were the brainchild of Zora Arkus-Duntov and his brother Yura Arkus-Dontov. Theyre rare as rare as any piece of performance equipment ever created, and yet they still exist (in limited quantities) 50 years after their birth. These conversion kits are sought after like pieces of jewels by speed-obsessed individuals interested in adding their names to the pages of land-speed record books and those who simply like rare and exotic things.
R & C published a three-part series by Tom Senter in 1971, entitled "Ardun White Paper." Tom chronicled the birth and development of the Ardun head kit and some of the successes of the few racers fortunate enough to own them.
Early Ardun heads were flawed in several areas cast steel push rods were too heavy, valve seats came loose due to expansion differences of aluminum and bronze, the stock valves were too heavy and exhaust manifolds were constricted. It goes on - A heavy valve spring didn'tt allow the higher rpm, the stock Ford ignition was inadequate and more problems needed to be solved by a pair of young California racers in the early 50s.
Many if these future refinements were a result of C & T Automotive, located in North Hollywood, California. Don Clark and Clem Tebow (more than mere engine builders) were credited with taking the flawed Ardun mechanicals and eliminating the many imperfections thus evolving the engineering and the unique heads presence in the racing community. Drag cars like Safeway Sandblasting, lakesters like The Lakewood Muffler Special and the SoCal Special coupe, and a number of very quick sprint car racers proved the Ardun-made horsepower in massive quantities, when the gremlins were held at bay. The C & T Ardun engines were capable of 300 horsepower in full-race configuration they powered many vehicles to speed-event glory and top speed record-book history.
In the mid 1990s it was a real estate developer from Pebble Beach, named Don Orosco, who had the vision and determination to write the next chapter on the Ardun cast-aluminum head.
Don was interested in doing some historic racing in Europe, and his strong desire to preserve some of our early hot rod heritage. Because of his determination and willingness to gamble no small amount of money, Don was able to create 30 sets of Ardun heads that were technologically superior, yet cosmetically and dimensionally accurate to the original. Don sold 27 of the 30 sets.
This is where the Don Ferguson family enters the story. Don Sr. and Don Jr.s use of and interest in the Ardun head is woven into the fabric of the Ferguson familys racing history (sidebar) The Ferguson Family.
Don Ferguson Sr. and Jr. were among the lucky few who raced the dry lakes and the Bonneville Salt Flats with Ardun equipped engines. Fatefully, this interest and desire to race led Don Ferguson Jr. to purchase the tools, drawings, and dies for creating more heat-treated Ardun aluminum heads from High Grade Alcoa 356 aluminum. This has a much lower porosity than the originals and allows for improved airflow. Helping an engine to breathe better is only part of what the Ardun aluminum head is about. In Part III of Tom Senters White Paper, he deals with the mysteries of the Ardun head. Rocker arm geometry, valve spring rates, valve weights and piston shapes factor into the equation.
Only mild cams are used with the Ardun due to increased lift-ratio and added gear loading. Wilder cams (higher profile) were known to cause coil bind or interference between intake rockers and the spring retainer. By changing piston shapes, combustion ratios are easily raised from a low end of 7:1, on up to higher rates of 13.4:1. All the technical information Tom recorded is part of the package offered by Don Ferguson Jr.