Dual valve springs can generate much higher pressure than standard single springs or the high performance version of these springs, making them extremely suitable for high speed 6500 RPM engines.
When assembling these valve springs, it is necessary to machine the cylinder head around the valve guide to create a gap for the two springs to slide into each other. Chrome moly or titanium valve spring retainers are also required to compress the two springs. Do not use aluminum retainers with these dual springs, as the higher spring pressure will compress the retainers.
It is also strongly recommended that reinforced rocker arm shafts be used, as the standard shaft retaining clips cannot withstand the force of these springs and will break.
Rocker shafts and valve spring clips are listed in the options tab.
Useful information from Paruzzi magazine and from our YouTube channel :
Look for more technical articles on the page Paruzzi Magazine