NEW GM 6.6 Duramax HD Performance Valve Springs | 98025825 | 2001-2018 Chevy/GMC Duramax 6.6L

This HD Duramax 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. 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 does a few things that negatively affect power. It increases the time delay from start of injection to start of combustion, it decreases the maximum pressure and maximum temperature reached in the cylinder and it increases the total time needed to completely burn the available fuel. Correct valve spring pressure is a very important piece of power production. If you are running a tuner on an otherwise stock truck with a VGT charger, based on exhaust drive pressure, these springs will help you. Now comes with our new tool steel retainers to prevent breaking at high horsepower or high RPMs

Features:

• Number of Springs Per Valve: Single
• Valve Spring Style: Standard
• Retainers Included: Yes
• Retainer Material: Tool steel
• Locks Included: Yes
• Outside Diameter of Outer Spring (in): 1.213 in.
• Damper Spring Included: No
• Valve Springs Coated: Yes
• Valve Stem Seals Included: No