Quote:
Originally Posted by spdbrake
Olddog makes some good points to inspect.
A tighter LSA does increase dynamic compression and chance of knock.
But your posted LSA (new and old are the same).
The new CAM is not what I'd call milder, although its less lift, it is a bit more Lopier with more duration.
35-425-8 - Xtreme Energy
From your post it appears this started right after the Cam change?
If so your new cam may be degreed wrong for your application.
This guide may be of help.
degree it in correctly and get it to last,cam install info, | Grumpys Performance Garage
ALWAYs check what you did last... |
Although I agree the new cam change is what probably caused the issue, there's a couple of notes that need to be made here:
LSA doesn't have anything directly to do with dynamic compression ratio. It's intake closing point only. I can grind two cams, with only the LSA being different and as long as the IVC event stays the same, the DCR will stay the same.
His new cam is much milder. Smaller duration. A smaller duration changes the IVC event.