How many engines use sodium filled/hollow valves?

[C4B4the04]

Had a discussion with someone today and they were quick to tell me "we still grind our own valve seats and lap them". Best I can recall, you can't do that to a filled or hollow valve. I said I thought there were quite a few cars on the road with higher tech valves than the old standards and he looked at me like I was nuts. Said the "mom and pop movers" still run traditional. I figured with the "tuner" scene that would have changed.

Any idea what engines do run them (other than the LS7, LS3, etc)?

Cassidy

[Black396]

Any idea what engines do run them (other than the LS7, LS3, etc)?

Cassidy

IIRC the intake valves are hollow stemmed and the exhaust valves are hollow stemmed and sodium filled on the LS6.

Also Ford has done some experimenting with hollow stemmed and sodium filled valves on some of the modular motors. I don't know if any of them made it into production though.

[C4B4the04]

I thought Porsche has using them for years in the pancake motors. I could be wrong on this. When I was a tech for Ford this was exotic stuff, I suppose manufacturing costs today are much less than a decade+ ago.

I think your description on the LS6 ones are right too.

Cheers,
Cassidy

[PWasinger]

Sodium filled exhaust valves have been around since before WWII in piston aircraft engines. Its purpose is to improve heat transfer up the stem so the valve head can withstand higher exhaust gas temperatures. The Wright J-5 Whirlwind engine that powered Charles Linbergh's Spirit of St. Louis across the Atlantic even had them.

[00vette]

Most chevy small blocks in trucks had them.