[1]With more new blocks and cylinder heads hitting the racing market, especially custom designed one-off models, Manton Pushrods is adding to its lineup, as well.
“We’re expanding the tool-steel line,” says Al Perkins. “Including new tool-steel tips with both the radius-cup and V-cup designs.”
Manton does not manufacture one-piece pushrods; instead, its focus is on modular or three-piece designs that precisely match the tips with the lifter body and rocker-arm adjusting screw. Most of Manton’s pushrods are constructed from different types and treatments of chromoly tubing; however, the solid-bar tool steel is gaining in popularity with high-horsepower applications such as Top Fuel, Pro Mod and tractor pulling. The tool steel is available in 3/8-, 7/16-, 1/2- and 9/16-inch diameters, and they can be ordered in straight or tapered design.
[2]
[3]
Still, the key is matching the tubes with the right tip. The copper radius cup is gaining more favor with engine builders. Manton offers this design for .281 and 5/16-inch ball-adjusting screws.
[4]“It works well with low-viscosity oil,” says Perkins, noting other advantages such as reduced heat and surface loading.
With so many possibilities, Manton requests that engine builders provide as much information as possible when ordering pushrods, especially when there’s boost, high spring pressures and engine speeds over 7,000 rpm. Manton will also want to know the previous pushrod information as switching to a stronger design will affect cam timing and possibly valve-to-piston clearance.
And don’t worry about sizes. Manton can go up to 3/4-inch diameter. And given the direction that engines in some of the outlaw categories are going, a 7/8-inch pushrod isn’t too far off in the future.
“We might have to try it someday,” adds Perkins.