Performance valve springs in this section suit the Ford Cleveland V8 engines.
These valve springs have been categorised in that in most cases special machining of the valve spring seat or valve guide for springs and damper clearance is required.
GENERAL INFORMATION
Typically your performance valve spring is matched to the lift of your camshaft. In each case for any given valve spring it has a maximum lift rating, however some camshaft manufacturers will recommend a suitable seat pressure to match the cam.
Most Street cams with a lift at the valve of 0.450 to 0.500 inch will require at least a single spring with an inner damper with a seat pressure of around 100-110lbs. This combo will typically rev safely to 6000rpm on cams with duration @ 0.050 of up to 235 deg.
To learn more about valve spring selection click here.
IMPORTANT NOTE: Some engines use push in rocker studs. The push in studs are an interferance fit in the head and will eventually work loose and pop out with performance valve springs, therefore valve spring seat pressures above 90lbs will require the heads machined and converted to screw in studs.
All hot street, racing track and street strip applications will require one piece strong valve spring retainers and matching collets.