V8Rumble

iTrader: (9)

Hey all,

I have a pair of the bare L92 heads, & as I've been looking at the parts needed to build 'em up, I've heard of both hollow & sodium-filled valves. Now the rationale behind the hollow units seems pretty straightforward, less weight/reciprocating mass, thus quicker revs & less stress on the valvetrain. But what's the advantage to the sodium-filled valves?

Second - does anyone have part numbers for these pieces? I've tried a couple of basic lookups, but hadn't found them yet.

Thanks guys.

CW 99 Z

The part number for the GM LS3 hollow stem intake valve is 12569427. Thats what Ill be using on my L92's going on my GTO. The only other options I could find for the big L92 intake valve size are Manleys and of course the standard L92 valve. For me that was the best option. As far as I know, nobody makes a sodium filled valve for the L92's. Its used mostly on the exhaust valve for better heat transfer and cooling of the valve/seat in high performance engines. Its used on the the 01-04 Z06 I know for sure, possibly on some of GM's other performance heads.

See5

iTrader: (53)

The GM LS3 intake valve is light (~90 grams) and priced right. It does not require a overblown dual spring to ~7k. Unfortunately the Manley ss and L92 valves are much heavier. The exhaust valves L92/LS3 are alloy and the same.

Mikey 97Z M6

iTrader: (37)

REV makes very affordable stainless valves for the L92's (about $100 cheaper than Manleys), and they're nearly the exact same weight as a stock L92 valve (intake =106g). Contact Richard at West Coast Cylinder Head (forum sponsor). I believe he now sells the hollow stem stainless valves also. He was very helpful when I was looking to buy valves for my L92's.

Mike