Location: Palmdale, Ca----- 734 RWHP & 585 RWTQ-----1/4 10.34 @ 135 MPH (New ET Eventually!)
If I remember correctly the LS6 (243) stronger spings than the LS1 (241) -
Hands down the LS6 head flows better than the LS1 due to the runner volumes and the smaller combustion chambers!
LS6 heads are refined and improved LS1 heads, basically:
- Intake runner volume increased to 210cc vs. 200
- Exhaust runner volume increased to 75cc. vs 70
- Combustion chamber is smaller at 64.45 cc vs 66.67
- Compression ratio is higher at 10.5:1 vs. 10.1:1
- "D" shaped exhaust ports vs round
If you mill the deck on the LS6 head 0.030" you will get 11.1:1 compression.
Flow #'s (Stock heads @ 28") Head vs Lift
LS1 / 137/ 187/ 207/ 223/ 228/ 237/ 242/ 243
LS6 / 156/ 204/ 225/ 243/ 257/ 268/ 275/ 278
In short smaller and more efficient combustion chamber allows quicker burn times, requires less ignition timing resulting in higher torque.
Honestly though are the sodium valves even worth bragging about? I feel so dumb now, I had a so-called buddy sell me hand ported Ls1 heads, milled,and lS6 springs( I use to think daaammn)...now all I think about is...what a waste of money, same as this damn GM ASA cam with it
well, IIRC, the sodium valves weigh 74 grams and the standard valves weigh 97 grams. You might not think this is much, but, it's about 31% more weight. Might not seem like much, but at 7000 rpm, it's a lot...
lighter weight valves require less spring pressure and require less force to open and close them. So, the engine makes more power.
The reality of this is that most of us will never build an engine to the point that this will make any difference at all in what we are trying to accomplish. Really, how many people actually build engines and car combos to extract the absolute most they can no matter the cost?
Nascar, NHRA, F1, IRL, ALMS, they do it.
The only person I know of that even thinks in this relm is RobZ.