Injector timing relative to cam angle
Injector timing relative to cam angle How is the injector operation controlled relative to camshaft (valve event) on the LSx? In other words, at what valve event does the injector shut off? When does the injector cycle begin or end?
TECH Regular
Joined: Oct 2005
Posts: 430
Likes: 0
I can't say for sure on LSx engines, especially at WOT, but surprisingly (considering all the hoo-hah re spray patterns, cone angles and injection pressure) typical modern North American engines with sequential EFI* inject fuel on a closed intake valve. The vaporization from the valve's heat and the 'shredding' effect of the high velocity flow as the valve cracks off the seat improves emissions and has little impact on power. *Obviously for older 'batch fire' ones like TPI, each cyinder gets its fuel 'whenever'.
Originally Posted by MadBill
The vaporization from the valve's heat and the 'shredding' effect of the high velocity flow as the valve cracks off the seat improves emissions and has little impact on power.
I just picked up a daily driver (Police Interceptor Ha Ha) and now the Camaro will be off the streets and on jack stands while I work the new fuel system.
Teching In
Joined: Feb 2005
Posts: 32
Likes: 0
From: Montana, USA
The Autronic SMC and SM2 aftermarket ECMs have mappable injector cycle timing, so you can determine the start of the fueling cycle relative to crank angle (think of it like ignition timing mapping for your fuel system) based on load and rpm.
In theory, this *could*, but not necessarily would, allow one to use much larger overlap cams with forced induction applications, without blowing fuel out the exhaust valve. Whether this is done or not for street vehicles is beyond me, though.
In theory, this *could*, but not necessarily would, allow one to use much larger overlap cams with forced induction applications, without blowing fuel out the exhaust valve. Whether this is done or not for street vehicles is beyond me, though.
