Mr. Gizmo

Does the LS3, . LS6(from the c5 Z06), LS9 and other LS based motors use the sodium filled 2 piece valves? I think the LS9 does, am not sure about the LS3.

tigertank

good question and y did they use these valves? weight? cost?

erick_e

The LS6 did, and the LS9 does.

The LS2, and LS3 do not.

erick_e

Gases flowing into and out of the combustion chamber pass by new hollow stem valves (shown at left). The stems of the exhaust valves are filled with a liquid sodium alloy. Since the exhaust valves operate at a much higher temperature than the intake valves, the liquid alloy enables better transference of heat from the exhaust valves to the valve guides and then to the engine coolant. The valves reduce valvetrain mass by approximately 368 grams. This lighter weight allows the valves to keep contact with the cam at higher speeds

http://www.corvettemuseum.org/specs/2002/power.shtml

Mr. Gizmo

From what I recall reading in the late 2005 issues of Car /Driver when they were testing the new to the market 2006 - c6 Z06, I recall talk in these articles of GM using this for the light weight for the high rev-ving LS7 motor. I would tend to think the sodium filled 2 piece valves would cost more to make because of the extra steps in the manufacture process -- I could be wrong about this.?

'06 Quicksilver Z06

I also believe that the LS9 exhaust valve, while hollow and sodium filled, has a smaller head than the LS7 exhaust valve.

tigertank

k that makes sense then lighter to keep contact with cam longer and ur right a 2 piece construction wud cost more guess GM tried to do the right thing