ford 4 pintle style, needle etc? Don't really know any other types but was curious is a certain type or brand of injector works better at helping to atomize the a/f mixture.

Also which one would be better for mpg if that is even a factor of injectors.

If an injector is bigger than what an engine needs then does that mean the motor is wasting excess fuel (mpg goes down)?or will the engine only draw how much it needs despite flow and pressure?

 

also, I have read that you can up the fuel pressure to the stock 24.9 injectors to make them higher or something along those lines. Since my requirements may only be like 26# or thereabouts after my cam install which is around the size of a cc502 could I up the psi if I need more flow? How would I do this and are there any downsides if it is only a moderate increase?

 

All types of injectors adequately atomize the fuel (when they are clean). That's not an issue when changing types. But the actual spray pattern - the angle of the cone formed by the spraying fuel - is different on different types of injectors. The stock Rochester injectors on your LT1 have a very narrow spray pattern, definitely narrower than the pintle style injectors. There's no evidence to suggest that there is any problem with using the wider spray pattern of the pintle type injectors in an LT1.

You will not see any measurable difference in fuel mileage based on the type of injector.

If you put a much larger injector in you engine than it needs, and tell the PCM the correct flow constant for the injector, your performance and your fuel mileage will not be affected. The PCM determines how much fuel the engine needs, based on the air flow, and sets the pulse width of the injector to deliver exactly the required amount of fuel. As long as it knows the size of your injectors, it will calculate the correct fuel amount.

The only possible problem is a grossly oversized injector, with a slow repsonse time that can not achieve the very low pulse widths (sub-1 millisecond) required at idle. In that case, you might notice a slight rich condition or roughness in the idle. People have routinely used 42# injectors in the LT1 with no discernable idle problems.

Yes, you can increase the capacity of an injector by running it at a fuel pressure higher than it was rated at. Your stock injectors flow 24.9 #/HR at 43.5 psi. To get them to flow 26 #/HR, you would have to increase the pressure to 47.5 psi. The stock LT1 injectors can easilly tolerate pressures up to 60psi. Above that, the ball & seat design may not respond well to the higher pressures.

 

Yes, you can increase the capacity of an injector by running it at a fuel pressure higher than it was rated at. Your stock injectors flow 24.9 #/HR at 43.5 psi. To get them to flow 26 #/HR, you would have to increase the pressure to 47.5 psi. The stock LT1 injectors can easilly tolerate pressures up to 60psi. Above that, the ball & seat design may not respond well to the higher pressures.
__________________

Hey Fred thanks for the response! Couple more questions though

do I need a Adjustable Fuel Pressure Regulator or can I have a pcm tuner tune it to run higher than 43.5?

Does upping the pressure still not affect gas mileage etc by running too rich?
I.e. the engine still only uses the amount of fuel it needs and I won't be just forcing more fuel into the motor whether it needs it or not?

Also what would running the psi @ 60 give my for #/hr?

thanks for the help!

 

The PCM can not change the fuel pressure. Only the fuel pressure regulator can do that. An AFPR is required.

As long as you program the correct flow rate for the injector into the PCM, reflecting the increased flow for the higher pressure, the PCM will calculate the exact pulse width required to supply exactly the same amount of fuel that the injector would have supplied at the lower pressure. To deliver the same amount of fuel, as pressure goes up, pulse width goes down. Maintains the same A/F ratio, does not run rich, does not affect fuel mileage.

An injector rated to flow 24.9 #/HR at 43.5psi will flow 29.2 #/HR at 60psi.