Why Choose Manton Stocking Pushrods?
3-Piece Stocking Pushrods: Custom-Pushrod Quality in an In-Stock Configuration
Manton three-piece stocking pushrods are manufactured using the same proven materials, components, and processes as our custom pushrods. We apply Manton’s proven tube and tip combinations to pushrods configured to replace factory pushrods.
This provides the performance and reliability benefits of a Manton-grade part with the convenience of an in-stock pushrod. For more detailed information about the design features of our three-piece stocking pushrods, refer to our “Pushrod Information” page.
Why Does Manton Offer 1-Piece Pushrods?
One-piece pushrods are a recent addition to Manton’s stocking pushrod lineup. This may come as a surprise because we have remained committed to the three-piece design for decades.
Although we remain confident that a three-piece design is the best choice for maximum pushrod performance, we recognize that not every application requires a custom, three-piece pushrod. One-piece pushrods are more efficient to manufacture, resulting in a more cost-effective option for the customer.
With this in mind, we decided to manufacture the best one-piece chromoly pushrod possible.
What Makes Manton 1-Piece Chromoly Pushrods Different?
Like all Manton pushrods, our one-piece pushrods are engineered to lead the industry in quality and performance. These pushrods stand out because they are made from the same material as our Series 3 pushrods, with all critical tip features CNC-turned directly into the part instead of forged. This manufacturing method provides the following benefits:
1. A 210-Degre Tip Radius
All Manton one-piece pushrods feature a 210-degre tip radius. This is what we call it when we undercut the back side of the ball, so that there is no material on the pushrod for the adjusting screw to bind with for atleast 210 degrees. This 210-degre radius allows the ball ends to accommodate high valve lift and angular movement while reducing the risk of binding within the rocker-arm cup.
2. Consistent CNC-Machined Tip Geometry
The shape of the pushrod tip can be manufactured more consistently with CNC machining than with a forged ball. These tips are held to the same dimensional standards as the Manton pushrod tips used in applications ranging from Top Fuel drag racing and off-road racing to Drag-and-Drive vehicles and select hypercars.
3. More Accurate Pushrod Length
The length of the pushrod can be held more accurately for two primary reasons. First, we machine the flat on the end of the ball during the same operation and with the same tool used to machine the ball surface. This means the overall length of the pushrod near perfectly represents the distance between the ball surfaces on each end of the pushrod.
With a forged-ball pushrod, one machine typically forms the ball end—the surface the valvetrain uses to establish effective length—while another machine cuts the flat that is contacted when the pushrod is measured with calipers. Because these features are produced in separate machines, the measured overall length may not represent the functional pushrod length as consistently.
Second, Manton one-piece pushrods are manufactured to a length tolerance of ±0.005 inch. This helps maintain consistent hydraulic-lifter preload for optimal performance.
What Are the Drawbacks of 1-Piece Pushrods?
There are two main disadvantages to manufacturing one-piece pushrods. First, the production cycle for a one-piece pushrod is measured in weeks, not days, and requires significant setup time. Consequently, producing small quantities is generally neither practical nor economical.
Second, a one-piece pushrod cannot provide the same optimized contact-surface properties as a three-piece pushrod made with dedicated bearing-steel tips.
These limitations, however, are not significant in every application. Manton maintains an inventory of the one-piece pushrods we offer, eliminating the extended production time normally associated with manufacturing them. In-stock orders can therefore be shipped promptly rather than waiting weeks for production.
The importance of the contact-surface properties also depends on the application. In many factory-style valvetrains, the pushrod tip may not require the additional service life or friction reduction provided by a dedicated bearing-steel tip. In these applications, a properly manufactured one-piece pushrod can provide far more durability than the engine requires.
How Does Manton Improve 1-Piece Pushrod Wear Resistance?
The contact-surface limitation of a one-piece pushrod results from using one material for both the structural tube and the ball ends. Unlike a three-piece design, it does not allow the ideal material to be selected independently for each function. This requires a compromise between the structural properties of the tube and the wear properties of the ball ends.
As a result, the ball ends are not manufactured from a dedicated bearing steel.
Some competitors use black oxide to give their pushrods the appearance of having a wear-resistant coating. However, black oxide provides minimal improvement in wear resistance and can wear away relatively quickly from highly loaded contact surfaces. Practically a black oxide coating only changes the color.
Others use a coating such as diamond-like carbon (DLC) to improve wear resistance and reduce friction. Although DLC can provide excellent friction and wear properties, any applied coating can flake off and cause catastrophic bearing damage else ware in the engine.
Manton uses a surface-treatment process that modifies the material’s surface rather than applying a separate coating. The treatment significantly improves the pushrod tip’s surface properties and cannot flake off like an externally applied coating.
This allows us to reduce the wear-related disadvantages normally associated with a one-piece pushrod.