Why LSA doesn't matter
I will be posting some more topics about pressure waves in the exhaust regarding stepped header designs versus conventional single step designs. Another topic that will be discussed as well is how a stamped collector changes pressure waves and dynamics versus a fabricated merged collector.
Stay tuned over the holidays for more info!
The Best V8 Stories One Small Block at Time
Tri-Y headers pair specific cylinders to scavenge together based on an engine's firing order and exhaust pulses. Tri-Y headers designed for a traditional small block chevy/big block chevy/W-motor, etc. with the standard 18436572 Firing order will not work correctly on an engine with a different firing order such as the popular 4/7 swap camshafts often used today. Probably of zero concern for an LS1 family engine since I'm not aware of any firing order swap camshafts used for those, but since this thread may be read by people on this site building an LT1 (92-97 not Gen V) then it may be good info for them to know.
I myself was reading this article after recently purchasing a new (but second hand) camshaft for my current build simply because it was about $175 cheaper than a new one. This camshaft has slightly higher duration than I was planning on, but a wider LSA so I was intrigued by this thread.
For what it's worth, the planned camshaft was 242*I / 248* E @ .050" on a 110* LSA. The bought camshaft is 248*/258* @ .050" on a 113* LSA.
Displacement = 478"
I do not expect the bought camshaft to have identical rpm range, peaks, and characteristics of the one I'd planned.....but after reading this I believe that for my build and budget it will work just fine.
IE: on the LS1 motor, at what degree do you want the valves to open? What determines this? I talked with roger vinci some years ago about this but memory fades me.
I know there's a too early and late degree range.








