VT VX VY VZ Holden Commodore Pac 650" 1905 Dual Valve Spring Kit V8 LS1 LS2 L98

PAC racing valve springs employ cutting edge technology in material advancements and processing resulting in superior race track results and reliability. PAC provide unparalleled attention to detail; from design to manufacture and customer satisfaction, in fact no detail is left unnoticed.

This particular set of dual 1905 valve springs is truly the tip of the spear. Shotpeened for superior resistance to wear and fatigue, and capable of happily handling aftermarket camshaft grinds up to a massive .650” valve lift (with 1.7 rocker ratio), you need look no further for the toughest valve springs on the market.

This custom kit includes all of the ancillaries required to handle whatever you can throw at it, including 16 valve springs (8 outer and 8 inner), 16 steel valve spring seats, 16 valve stem seals and 32 steel collets. As such this valve spring set is built to withstand the rigors of drag and circuit racing applications, not to mention serious street performance.

At Tuff Car Parts we recommend dual valve springs rather than single valve springs for the majority of camshaft upgrades. What is the difference, and why do we recommend duals? A single spring kit is one spring that supports the valve on its own whereas a dual kit has the outer spring as well as a smaller spring inside. The reason we recommend dual spring kits is because in the highly unlikely event of one of the dual valve springs failing, the other spring (typically the inner spring) will still be in tact to hold the valve up and prevent it from dropping into the engine, potentially saving a costly engine rebuild. A single valve spring does not have this second spring to fall back on.

So will the PAC 1905 suit my needs? The answer would be a resounding “yes” if you;
1.    have a camshaft grind greater than .625” lift at the valve, noting that the 1905 spring copes with up to .650” lift camshafts
2.    The vehicle will be used in burn outs, drift or other situations whereby the engine will hit or sit on the rev limiter on a regular basis
3.    Knowing that valve springs can and do break, you want the additional insurance and have it in your budget to do so.

The stiffer PAC 1905 dual valve springs help prevent both valve float and valve bounce. Valve float is an adverse condition which can occur at high engine speeds when the valve does not properly follow the closure phase of the cam lobe. This reduces engine efficiency and performance, and represents a significant risk of severe engine damage due to valve spring damage or pistons contacting the valves. They also negate valve bounce which is a related condition where the valve does not stay seated due to the combined effects of the valve's inertia and resonance of metallic valve springs that reduce the closing force, and allow the valve to re-open partially.

Specifications:

• Part Number:        PAC-1905
• Description:        LS Dual Spring  
• Spring Type:        Dual
• Lift Max (in)”        0.650”
• O.D. (in):        1.304
• I.D. (in)    :        0.950
• Inside Spring I.D. (in):    0.694
• Install Load (LB):    160
• Install Height (in):    1.800
• Open Load (LB):    425
• Open Height (in):    1.125
• Coil Bind Max (in):    1.020
• Damper:        No
• Rate:            392

Warranty: Tuff Car Parts is committed to giving our customers the best buying experience available online when purchasing automotive parts. This includes us proudly supporting all products we sell with our own 12 month warranty. If a part fails and is covered by a manufacturer’s warranty Tuff Car Parts will gladly follow up all warranty claims on your behalf, meaning you can get a replacement as soon as possible without the headache of dealing with warranty departments yourself. Collateral damage is not covered by PAC Racing Springs, and as such cannot be covered by Tuff Car Parts.