bbowerman

Hey guys recently got my build done.
Stock heads ported with 2in s6 valves
4.8 flat tops
Clevite h main and rod bearings
Mls head gaskets
Custom grind cam 572/566 218/221 115lsa


Anyways sounds great haven't got it ironed out yet
Question is do you think I will need an injector upgrade?

bbowerman

Video

bobfig

sounds good, almost what i was going to do but i dont have a cam, yet.

Suburbazine

What year engine, was it Flex Fuel compatible? Some of the earlier (99-02) engines had mosquito feeders on the fuel rail that barely moved enough fuel to keep the engine alive. If you have the 36# injectors (Flex Fuel) then you're golden. If you have the 22 or 24# injectors, you're golden brown with a touch of crispy piston.

bbowerman

It's an 01 engine non flex fuel. The reason I am wondering is because before I had a tune can and longtube headers and it was faster and pulled harder than it does now. Just looking for some insight on what it could be.

Bluecollar Hotrods

iTrader: (18)

I'm guessing you haven't had it on a dyno or hooked up to a wide band to check the a/f ratio? I would make a few pulls on the street and read the plugs at the very least. And hooking up a FP gauge and tape it to the windshield to see if the pump is up to snuff much not be a bad idea either.

bbowerman

did some tuning on it with the hp tuners laptop. fuel trim is showing lean. plugs look lean to me. yellowish tip. guy said i need better injectors. just curious i see all these 370-420hp 5.3 builds but never hear anyone say they put injectors in them? just wondering how they are doing it.

bobfig

they probably run them over 90% duty cycle

the calculators online say that for 400hp flywheel at 80% duty cycle you should need about 32lb/hr

bbowerman

duty cycle was at 115%

bbowerman

at like 4000 rpm