Classic Austin Mini rocker assembly 1.5 hi lift forged rocker

Hi-Lift at half the cost! Race engine practice at street car prices. Using 1.5 ratio high lift rockers has almost become the standard among the racers but at almost $600 for a set of full roller high lift rockers, it's too expensive for most street guys. Mini Mania also has cast 1.5 ratio rockers that are a direct replacement for the stock version AND are half the price. Complete kit includes eight rockers, adjusting screws, four steel pedestals and rocker shaft.

The most often talked about "high lift rockers" are the latest design "roller" type (see C-AHT438), but the main reason "high lift" rockers were designed was to allow easy bolt-on performance without having to disassemble the engine to change camshafts. This performance improvement is achieved with or without the "roller" added option. The standard "high lift" rockers provide a ratio of 1.5 vs. the stock 1.25. (The "roller tip" type also have a 1.5 ratio). This Keith Dodd cast iron rocker set includes rockers and special offset pedestals with high performance rocker shaft!
Produced in the same way and material spec as the 12G1221 'cast' rocker, but to CAD-CAM developed dimensions. This reduces the weight (15% lighter than the stock rocker), whilst insuring optimum strength. This reduction in weight allows lighter valve springs to be used, and extends RPM potential of the fitted spring by some 5%. Valve clearances should be opened up by .003" over recommended settings, although up to .005" can prove beneficial with certain combinations. Using the 1.5 ratio not only increases the maximum lift, but it also means that the valve is open approximately 20% more at any given point- although opening and closing periods remain the same. This vastly improves volumetric efficiency and therefore power output. Also fits the Sprite , MG Midget , and Morris Minor.

SPECIFICATION: Material is drop forged EN16 with the valve pad face hardened to 52.5-55 on the Rockwell  C scale. RATIO: Rocker ratio is 1.5 as opposed to 1.25 of the standard rocker.

TAPPET CLEARANCE SHOULD BE 3 THOU MORE THAN STANDARD. ON REALLY HIGH LIFT CAMSHAFTS AN EXTRA 2 THOU AGAIN MIGHT BE BENEFICIAL.

Ensure that posts, spacers and rockers are evenly distributed along the length of the shaft to allow smooth pivoting.

On no account must the valve springs be allowed to become coil-bound as this will place undue stress on the rocker and could lead to failure.

At least 0.100" should be present between full valve lift and spring crush, or 0.030" between each coil of spring at full valve lift. The advantages of this assembly are similar to fitting a higher lift camshaft, but without the ordeal of stripping the engine. Only the knowledge of adjusting tappets is required. The valve actually opens and closes at exactly the same point, but the valve is open by about 20% more at any point on the camshaft lift curve which promotes airflow, accentuated when used on a high cylinder head.

WARNING This Hi-Lift rocker assembly does not appear to work well with the old meteor range of cams from Kent Cams or the Magnum range from Pipers, which are both special types of cams. They are however, designed to work with the Megadyne Kent cam range.

CHECK The adjustable nut is AF spanner size as opposed to the standard Mini size of 7/16 AF on pressed rockers. The 1300cc range and  S forged rockers are AF.

PART NUMBERS Adjusting screw - AEG167. Nut - NT605061.