Safely increasing cam lift or maximum engine RPM can require new valve springs. On the 3800 we use LS1 beehive valve springs which means that when running new springs you will also need the beehive style LS1 retainers.
105# springs 105# @ 1.800"
Open 293# @ 1.200"
Spring rate 313#
Coil bind 1.140"
125# springs 125# @ 1.800"
Open 367# @ 1.150"
Spring rate 373#
Coil bind 1.100"
136# springs 136# @ 1.800"
Open 412# @ 1.170"
Spring rate 438#
Coil bind 1.125"
105# springs are rated for up to .600 lift and work well with a 1.9 rocker or VS cam. Boosted shifts at or less than 6000rpm.
If you run any valve spring with over 105# of seat pressure, it will require a Rollmaster double roller timing chain.
125# springs have the same spring rate as the 105's but the seat pressure is higher. Rated for up to .600 lift they work well for XP, XPZ, or NIC or custom setups with aggressive ramp rates or high RPM.
136# valve springs are intended for the larger high lift camshafts, for example our XPZ and shift points over 6400rpm. (currently as of 11/26/2014 this is the best performing spring we offer)
Why install valve springs?
When boost is increased, that boost is pushing on the back side of the intake valves, therefore your valve spring pressure is reduced. So when you add valve springs it allows you to rev higher and increase your boost without losing any performance to valve float. What valve spring should I order? 105# - good for any NA setup or a boosted 1.9 rocker or a VS cam setup shifting at 6000rpm with less than 10psi of boost. To shift over 6000rpm with boost, we would run the 125# springs. The 125# valve springs are good for XP, XPZ, NIC cams shifting up to 6400rpms at 14psi or less of boost. For the people that want to shift over 6400rpm, you will want to run the 136# valve springs.
Some users have reported that in naturally aspirated applications the LS6 springs have excessive noise and cause false KR readings at certain rpm points. We have not confirmed this.
1.80" recommended install height.
These are all packaged in sets of 12.