Hamilton Diesel 5.9L 12 Valve Cummins HD Springs & Billet Retainers/Keepers

Hamilton Diesel's 12 valve springs were designed to fix many of the problems in the 12v valvetrain.

Factory and “60lb” springs do not have enough spring pressure to adequately control the valvetrain in all conditions. In fact at 1.4” they have exactly the same pressure as factory springs!. 

Trucks running over 3500rpm & 35lb's of boost WILL experience valve float with "HD" 60lb springs.

These springs are good for up to 5000RPM & 100PSI of boost. 

Features:

• Beehive design to reduce valvetrain mass, increase initial acceleration of the valve, and to cancel spring harmonics.
• Nitrided to prevent corrosion.
• Made with only the best ovate wire available to handle cams with high lift.
• Must be used with our 10° locks and ultra-light 4140 retainers.
• These springs will easily handle cams with .700” lift.

Our 10 degree chromoly retainers weigh in at 11.8 grams a piece, factory retainers weigh around 40 grams a piece and some Ti replacements on the market are almost 25 grams. 

Seat Pressure vs Lift of Hamilton Diesel 12 Valve Springs VS "60LB" Valve Springs:
lift           Stock    60lb        HD12
1.940”   88          150        155
1.900“   98           156         165
1.800“   125         170        200
1.700“   150         187        240
1.600“   182         210         285
1.500”   210         225         327
1.400“   245         245         365

This Gets you the HD12vs-1 competition springs.
Picture shows comparison of 60LB Valve Springs & Retainers VS Hamilton Diesel Springs & Billet Retainers.

Part Number: 07-s-001