Valves for supercharged LS

[lewy-d]

I'm building a 6.0 LS with LSA heads (GM #12675872). I believe the valves in it from GM
are nothing special. The exhaust is non-magnetic. The intake is. Does a supercharged engine need an inconel exhaust valve? Could a titanium intake valve last? Are Hollow stem valves durable in this application? Are the GM titanium and inconel valves good valves?
thanks for helping.

[ProPower engines]

The LT4 in the corvette used Ti and inconel valves. They did seem to last for the boost they were under.

Depending on what your doing for boost everything has their limit.
The intakes I am told are made for GM by Del-West, They make a very good valve. Not sure on the exh. valves but again they seem to work fine in their stock application.
I think that a major increase in valve spring pressure will be the weak point for either of the GM stock valves.

As far as extra exhaust temp goes inconel valves are the way to go.
Stainless valves will handle some heat and moderate spring loads but if they get hot enough they will tulip on you.
If the chamber temp is high enough the intakes will as well. See this all the time on marine engines where guys did not use the correct exhaust valves and got the timing curve very wrong


How much boost are you planning to run?? A few lbs may not be that big of issue for stock valves as GM already does it

[lewy-d]

Thank you for the reply. Planning on 14-20 psi. It'll have a cam, which means more spring pressure. There is a hollow sodium filled GM valve. I think it comes in the LS9? And there's a titanium GM valve. They aren't super expensive, but I don't know if they are decent. I like Manely stuff. but some of their parts are back ordered like everyone). What's your recommendation?

[ProPower engines]

Thank you for the reply. Planning on 14-20 psi. It'll have a cam, which means more spring pressure. There is a hollow sodium filled GM valve. I think it comes in the LS9? And there's a titanium GM valve. They aren't super expensive, but I don't know if they are decent. I like Manely stuff. but some of their parts are back ordered like everyone). What's your recommendation?

That may be over the limit for boost on stock stuff.
Personally I would use Manley or Del-West depending on size and valve.

Gm does sell CNC ported fully assembled heads that come with Ti Intake and inconel Exh. with Ti retainers and when comparing a core set of heads and all the work they were a bargain. Had a customer buy some from a dealer up here in Canada I believe they were in Edmonton Alberta for just under $2500 cdn money.

I did check them over and had to touch up a couple seats but they were very well done and for the cost they were a better deal then getting cores and starting that way

[panic]

Exhaust seat .080" minimum