If you are over 30lbs of boost/drive pressure or over 3500rpm with your 12valve, you are experiencing a few negative things. First, valve float, which can cause serious damage to the valvetrain. Second, intake and exhaust valves can be blown open by boost and exhaust drive pressure which allows reversion. Reversion can hurt your power potential by allowing exhaust gasses to enter the cylinder on the intake stroke. Inert gasses in the exhaust, when re-introduced into the cylinder shield the fuel particles from oxygen in the cylinder.

A direct drop in replacement for engines with higher than stock boost levels and horsepower. Do not worry about valve float again! Fits 6.0/6.4 Ford Powerstrokes. If you have an aftermarket turbo and are running more rpm than factory, you will see a few problems if you are still using OEM springs. First, valve float, which can cause serious damage to the valvetrain. Second, intake and exhaust valves can be blown open by boost and exhaust drive pressure which allows reversion. Reversion can hurt your power potential by allowing exhaust gasses to enter the cylinder on the intake stroke. Inert gasses in the exhaust, when re-introduced into the cylinder shield the fuel particles from oxygen in the cylinder.

This spring allows you to run higher boost pressures and rpms without experiencing valve float. No extra cylinder head machining is required to run these springs. Depending on installed height, you will have approximately 130# installed pressure.

The Hamilton Cams 07-S-6.7F Performance Valve Springs eliminate valve float caused by elevated RPM and boost pressure in your Ford 6.7L Powerstroke. If you have an aftermarket turbo and are running more rpm than factory, you will see a few problems if you are still using OEM springs. First, valve float, which can cause serious damage to the valvetrain. Second, intake and exhaust valves can be blown open by boost and exhaust drive pressure which allows reversion. Reversion can hurt your power potential by allowing exhaust gasses to enter the cylinder on the intake stroke.