ROLLER TIP ROCKER ASSEMBLY 1.5 RATIO – LARGER SHAFT [C-AHT446EVO]

1.5 Ratio Roller Tip Rocker Assembly – Competition Cradle Type

Suits 1275cc Big Bore Engines

Serious valve train upgrade for high performance 1275cc Mini engines. This 1.5 ratio roller-tip rocker assembly is designed to maximise valve lift, improve valve train stability, and unlock additional horsepower from performance camshaft combinations.

Manufactured using a rigid cradle-type design with an upgraded heavy-duty rocker shaft, this assembly dramatically improves strength and stability compared to standard pressed steel rocker setups. The larger shaft size helps minimise flex under high RPM and aggressive camshaft loads, making this setup ideal for fast road, rally, sprint, and race engines.

The lightweight alloy roller-tip rockers reduce side loading on the valve stems while significantly reducing friction and valve guide wear. This allows the valve train to operate more efficiently at higher engine speeds while improving long-term durability.

The 1.5 high-lift ratio increases valve lift by approximately 20% over standard rockers at any given point in the cam cycle. While the camshaft duration itself remains unchanged, the valves open further and flow more air and fuel into the engine, greatly improving volumetric efficiency and ultimately increasing power output.

This upgrade works exceptionally well with modern performance camshafts where improved cylinder head flow and valve control are critical.

Features

• 1.5 ratio high-lift rocker assembly
• Roller-tip lightweight alloy rockers
• Cradle-type competition design
• Heavy-duty upgraded rocker shaft for improved rigidity
• Reduced valve stem side loading
• Reduced friction and valve guide wear
• Improved valve train stability at high RPM
• Increased valve lift and airflow
• Excellent upgrade for modified 1275cc engines

Assembly Includes

• 8x Lightweight alloy roller-tip rockers
• Centreless ground roller tips
• Competition thick-wall rocker shaft
• Steel pedestals
• EN24 AEG167EVO heavy-duty Allen key adjuster screws
• C-AHT449 multi-point lock nuts

Important Installation Notes

• Suits 1275cc big bore engines only
• Ensure all rocker pedestal posts are tightened down evenly to avoid stress fractures in the rocker shaft
• High-lift rocker assemblies often require additional rocker cover clearance

Recommended rocker cover:

• FP24 MPI rocker cover

Many aftermarket alloy rocker covers will also provide sufficient clearance for these high-lift rocker assemblies.

For anyone building a serious A-Series performance engine, this is one of the most effective bolt-on valve train upgrades available. The engine revs cleaner, breathes harder, and responds faster, especially when combined with a quality camshaft and cylinder head package.