"Slo-mo-shun IV" Groomed for Big Races 
Speed trials on a new unlimited class boat, Slo-mo-shun IV, are proceeding in Seattle. Owner is Stanley S. Sayres, for many years a fast boat racing enthusiast. Sayres is grooming his boat for entry in the Gold Cup and Harmsworth races next year.
In a recent test run on Seattle's Lake Washington, the Keller water speedometer passed the 100 mph mark. The engine had a lot of throttle left, but the driver ran into steering difficulties.
This trouble was rectified by the installation of a complete new worm gear steering mechanism and in succeeding bursts of speed on the lake the powerful 1800-hp, 12-cylinder Allison aircraft engine will be opened up to see what the boat will do.
"She planes perfectly," Sayres reported. "We are very pleased with the results so far, but we want to avoid making optimistic predictions as to her final performance. We've only run it two and one-half hours so far."
Slo-mo-shun IV is a four-point hydroplane with a somewhat different distribution of weight than usual. The bottom of the sponsons differs from usual construction. She is 28 feet overall with 11 feet 4 inches beam across the sponsons.
The engine installation also differs from the usual type of Allison installations in racing hydroplanes. Instead of the usual forward Vdrive, the engine drives the shaft directly aft, with the 3-to-l step-up gear box mounted in the position of the original aircraft reduction gear. Since the engine turns up to 3000 rpm at 1800 hp, the maximum propeller speed will approach 9000 rpm.
The step-up gear was built in Seattle by Western Gear Works and was designed and engineered by Donald B. Spencer, supervisor of the engineering department. The gear installation was made with the cooperation of the Allison company and utilizes Fafnir bearings, designed to give it rugged, dependable service.
Slo-mo-shun IV was built by Anchor Jensen, Jensen Motor Boat Company, Seattle. Framing is oak. Bottom and sides are constructed of five-ply mahogany plywood, laminated especially by the Elliott Bay Mill Company of Seattle. Plies were laid up at 45ē angles for increased strength. As yet the cowl, fin assembly and hood have not been installed.
Running surfaces on the sponsons and after plane have a layer of 1/8-inch duraluminum. Duraluminum was also used for framing, bracing, and skid fins.
Designer of the racer was Ted O. Jones, a supervisor at Boeing Aircraft Company, Seattle, who has had much previous experience in designing 135 and 255-cubic-inch hydroplanes. Jones has also participated in a number of races in Southern California. Sayres and Jones will share the driving in the races next year.
Sayres has been a figure in Northwest racing circles for many years. He began some years ago by entering outboard races in Pendleton, Oregon.
He later came to Seattle and after several years the racing bug bit again. His first race boat was built in 1938, Slo-mo-shun I. He later built its successors, Slo-mo-shun II and III, all 225 hydros, which Seattle racing fans will remember. Slo-mo-shun III, which he still maintains, is a Division I racer with a 255-cubic-inch piston displacement. Sayres divides his time between his racing boats and his business, the American Automobile Company, Chrysler distributors.
All the test runs of his new boat will be held on Lake Washington. Sayres is currently completing a fine home on Hunts Point on the eastern lake shore, near Bellevue. A modern boat house has been built which will provide dry storage for his two racing hydroplanes and also a stall for his 28-foot Hacker runabout.
Sayres thus joins a select group of Pacific Coast owners of speed boats capable of competing with the best in the world — Stanley Dollar, .Henry Kaiser and Morlan Visel.
(Reprinted from Pacific Motor Boat, December 1949)