Necessity for inconel ex. vales in mild turbo ap?

[rewguy]

Seeing all these stock LS longblocks survive quite a bit of boost...… If I had a simple pump gas turbo sbc with decent stainless valves, and a max of 10-12 lbs of boost, small twin turbos, and 600 max hp...…..That should give me no issues, correct?

[KnightEngines]

Correct.
My old twin turbo 308 holden ran cheap ass black steel valves, turbos were small (old T3) & the exhaust manifolds would glow red through the heat wrap after a hard run.
Made somewhere around 600-630hp.
Never missed a beat.
Use .060" wide seats on the exhaust.

[Caprimaniac]

Correct.
As long as combustion temps kept on spot (AFR, timing etc) and decent length of guides and seat contact area to cool the valves; no problem.

And noe Hollow-stem valves (or maybe they'll handle the Power Level you mentioned? I did not try, but general rule is NO Power adder w/ Hollow stem vlaves.)

[Orr89rocz]

Yup i’ve run 30 psi 1400 hp sbc with regular stainless valves by Ferrea. Never an issue

Ran box stock AFR 195 heads on another combo 800 hp 14 psi for a few years as well no issue

[peejay]

Duty cycle is key. For drag racing or quick squirts on the street, okay.

On a road course or in a boat or something, I'd want the good valves.

The OEs generally engineer for high duty cycle because they have no idea what someone is going to do with their products.