Fathead Hemi – Low Ratio Rocker Arm System ( Raised Exhaust Shaft )

Manton Fathead Hemi Low Ratio Rocker Arm System ( Raised Exhaust Shaft )

Explore our Fathead Rocker Arm Assembly with Low Ratio Stands and Tool Steel Construction.

Includes:

• Complete Rocker Arm Assembly with Adjusting Screws and Jam Nuts

Our commitment at Manton is to deliver valvetrain solutions that excel in performance, reliability, and durability, especially in high-speed applications exceeding 10,000+ RPM.

Addressing crucial aspects, we’ve innovated our rocker arm assemblies with solutions to key challenges:

Rocker Arm Geometry: Precise rocker arm geometry is vital, particularly at high RPMs. We’ve applied fundamental geometric principles to ensure optimal performance under extreme conditions, considering manifold boost and cylinder pressure dynamics.

Oil Transfer and Leak Prevention: Our assemblies feature forced oiling through the fourth cam bearing, typical of Chrysler type blocks. This ensures continuous lubrication to both shafts via radial transfer passages, including the intake and exhaust adjusting screws and pushrod cup interface. Tight clearances between rocker arm stands and shafts minimize oil spillage and pressure loss, further aided by threaded plugs in each shaft to prevent any pressure loss at the shaft ends. Switching from stock rocker arm assemblies to Manton’s can boost oil pressure by 10 to 15 pounds, and our assemblies do not require restrictor jets.

Strength, Stability, and Rigidity: Enhancing durability, each rocker arm is fortified with load screws, doubling assembly strength. Heavy-duty rocker arm shafts securely attached to stands with load screws contribute further to robustness. Every material is carefully chosen for its specific performance, undergoes meticulous heat treatment, ensuring consistent valve train control even at extreme RPMs.

Years of rigorous testing, including extensive race day trials and lab testing, validate our assemblies for stability beyond 11,200+ RPM. They significantly extend the service life of valve springs, roller lifters, and all valvetrain components, performing exceptionally in demanding environments.

We refer to our stands as Low and High ratio. This reference is to the exhaust rocker arm ratio. Low being 1.6 to 1 and high being 1.7 to 1. The intake 1.8 ratio remains the same in either choice.

Discover precision engineering with our Fathead Rocker Arm Assembly, designed to deliver unparalleled performance and durability in competitive racing and high-performance applications.