All being equal, are ls series engines quieter than an equivalent sbc? If so that's good

 

Not that I know of, they have a different sound. But stock for stock I don't think there is a large enough difference to be noticed if there is any difference.

 

That's part of the reason for the skirted block vs the traditional sbc. NVH issues are said to be reduced but I can't honestly say that between properly built sbc and LS engines there is a noticeable difference. Maybe I'm just getting old.

 

In my opinion the old sbc is quieter, I had one in a camaro with a electric fan and when the fan was off you would have to do a double take or stick your head in the engine compartment to verify if it was running or was shut off.

 

some stock ls1 engines are kinda loud on cold starts from the pistons slapping till the engine warms up,