According to Jack, these pumps' computer-designed impellers move water more efficiently. Their radial-bearing-exclusive construction will take more belt tension than even the ball-bearing-equipped stock pumps. They also feature a completely redesigned and enclosed seal that reportedly bears contemporary coolant pressure levels without weeping or failing as the originals certainly will under similar circumstances.
Jack offers these pumps in two basic body designs, each with two subsets. The first design fits '37-48 engines, and as such lacks the bypass configuration. The second design fits '49-and-later engines, and as such features the appropriate bypass. It's the two subsets that really make these pumps shine, though; both body styles are available with single-sheave aluminum pulleys in a choice of the early or late pulley offset.
Above and beyond having really beautiful pumps, it means early-engine adherents don't have to endure irrelevant and awkward-looking bypass ports on their engines. What's even more important than that, however, is the fact that late-engine devotees don't have to forsake the bypass design or the improved impellers to use crab-type ignition systems.
Speedway MotorsRecently, "Speedy" Bill Smith incorporated improved bearings and seals in several popular pump styles. He has them cast from a high-nickel iron and spot-faces the fastener-mating surfaces to ensure proper contact.
While Speedway retained many of the stock design elements, including the six-blade-straight impeller for the early pump and the belt configurations, all boast tighter internal tolerances, combination roller/ball shaft bearings in lieu of all-ball bearings or bushings, and improved ceramic seals, the latter reportedly similar to those used in Nextel Cup race car pumps.
Even though Speedway doesn't offer a modified version of the '49-52 Mercury pump with the raised mounting pad, it does offer modified versions based on the '49-and-later Ford and '53 Mercury truck pumps in either wide or narrow pulley configurations.
Cornhusker PumpsWhile Flathead Jack and Speedway retained the design attendant to all Ford Flathead engines, Gary Mussman at Cornhusker Rod & Custom bypassed the design altogether. Make no mistake; this kit visually transforms the feel of the venerable Flathead.
Cornhusker's conversion doesn't use two pumps; it uses one, la overhead-engine design. Ironically, it isn't even a Ford unit; it's the pump Chevrolet used on its own '58-65 348 and 409 engines. In fact, it even uses small-block Chevrolet pulleys.
These bolt-on kits include a brand-new pump on an outright basis, adapters, hardware, gaskets, and instructions. While the kit is an entirely bolt-on affair, the optional bushing kit to mount the engine higher in the chassis requires welding brackets to boxed framerails. While Cornhusker offers kits to fit various stock Ford and hot rod applications, its versatility is limited only to a builder's imagination and fabrication skills.
Since this pump features conventional late-model seals and bearings, it'll withstand conventional belt tension and coolant pressures; however, the adapters don't accommodate the late-engine coolant bypass function.