I'd like to call it a "Piston Damage Light"
Cheers!
The old BB Mopar Combustion-Chambers (
and particularly the 426 Hemi) needed a LOT of initial advance to produce good torque. Typically when they would produce light-ping under abnormal grunt conditions, they would make really good power at that particular altitude.
2 degrees of timing (either up or down) made an enormous difference in power production on those older engines. BB Fords didn't seem to care.
The original Hemis' had great volumetric-efficiency but poor combustion-efficiency. As there was no mechanical squish/quench going on, the plugs took a real shit-kickin'. I used to change plugs in my old 426 Hemi every 1500 miles.
Rising above the 10.25:1 compression ratio on the street-hemi was dangerous at best, even with decent fuel.
The 12.5:1 Race Hemis weren't long for this world. You can only do so much with piston top design to try to encourage Combustion Chamber cooling without mechanical Squish/Quench.
Sport bikes with true hemi chambers make it easy to light-off the mix and because they rev into oblivion, they don't really have time to have flame-front abnormalities (detonation).
Although the modern Viper engines Gen III Viper (OEM or Striker-headed) don't require high initial advance, there is (like with any other engine) a sweet-spot. With adjustable rockers I can play around with cam "timing" and favor either low OR high rpm power production through valve lash. Changing the valve lash with my current 11:1 pump-gas build keeps the knock-sensors VERY busy indeed as it makes the cam considerably smaller and builds cylinder pressure early (as the intake closes earlier).
IF I had a modern 8-speed in our trucks, it wouldn't be a concern to operate with timing on the fringe.
But I don't, and the 2-3 and particularly the 3-4 shifts put considerable load on the engine. That's why I had Chris Jensen wind out the shifts as far as possible through tuning. The 3-4 shift at 200 km/hr is an absolute treat!
I'm actually surprised there is time during a 1000 rpm WOT kickdown (while in 3rd or even Overdrive) to actually kickdown into 1st gear then complete a solid 1-2 shift without bouncing off the hard-limiter. I think I'm maxed out here. If I added another 2 or 3 hundred horsepower, I doubt the 48 RE could keep up. And no, I DO NOT WANT A 6-SPEED.
As I can't hear an engine ping anymore, I should be able to see it ping!
More Sunday-Afternoon ramblings...