PAC-1371-16 0.716 in. ID – 1.374 in. OD – 1.950 in. installed Height – 0.700 in. Max Valve Lift

0.716 in. ID – 1.374 in. OD – 1.950 in. installed Height – 0.700 in. Max Valve Lift

PAC Racing’s 1300 Series Drag Race Dual Valve Spring is the manifestation of the latest technology in the drag racing valvetrain aftermarket. Traditional springs were made with higher loads and rates without concern of spring mass and frequency. PAC Racing has taken years of research and coupled that with exotic new heat treatment methods to produce the next generation of drag racing valve springs. The 1300 Series springs feature a 15-30% reduction in physical mass. This, coupled with a natural frequency increase of 20%, enables your engine to rev higher, faster, and last longer even with aggressive camshaft profiles. These springs are constructed of our signature PACaloy super clean wire and are heat-treated in-house for precise spring rates and enhanced strength. They undergo a multi-peen process to optimize service life as well. Unique to the 1300 Series, these springs then receive ID/OD chamfer finishing, a run through the polisher, and a Nano-Peen™ proprietary surface treatment to improve operating cycles.

Built using our signature PACaloy super clean wire to ensure strength and durability
In-house heat-treating for precise spring rates and increased strength
Multi-peen process to optimize service life
ID/OD chamfer finishing
Polishing to improve operating cycles
Nano-Peen™ Proprietary Surface Treatment

Outer Diameter – Outer Valve Spring    
1.374 IN

Inner Diameter – Outer Valve Spring    
1.000 IN

Inner Diameter – Inner Valve Spring    
0.716 IN

Installed Height    
1.950 IN

Installed Load    
150 PS

Open Height    
1.250 IN

Open Load    
455 PS

Open Load / Height (Valve Open)    
455 LB @ 1.250 IN

Valve Spring Rate    
436 PS

Max Coil Bind    
1.190 IN

Max Valve Lift    
0.700 IN

Recommended Valve Spring Retainer – 300 Series    
R317, R348

Recommended Valve Spring Retainer – 500 Series    
R517, R552

Recommended Valve Spring Seat    
S114, S115

Valve Spring Series    
1300 Series

Valve Spring Type    
Dual

Valve Spring Application    
Circle Track

Primary Market    
Circle Track|Street Performance