Re: timeing setting for 454 7.4L
as your modifying the original setup 12* may work. your adding extra fuel so you may need to light up the mix. the more timing advance you can run without detonation the more power the engine can make, if you can get the air and fuel to it. on a suck,squeeze,bang and blow motor we can control how much fuel, how much air what type of combustion pressures and when we light the mix. we cannot control when the fire goes out. but it must go out before the next cycle. so the earlier we can light it the better off it is. however if its lit to early bad things can happen. the difference between 12 and 8 is not likly to be noticed. thats why on most EFI motors that use a knock sensor the first thing the ECM does at knock detect is open the fuel pulse width, if knock is still detected it will open more and start retarding timing. that big holley will usually run slightly rich. most all do. but when you look at timing not only do you have base timing but total advance has to be verified. so its time for a WOT session with a timing light to verify WOT timing. idle timing is a function, total advance is the critical one that can bite ya. to late and it will cause abnormal heat and melt valves, to early and it will cause undue stress on te reciprocatin assy and detonate holes in the piston. thats wy I use a lite with an advance and tach functions.
