FS: Delphi 26lb fuel injectors

[XfireZ51]

Originally Posted by randy ransome

I have a 368 cubic inch, Cory Henderson built, with a 63mm throttle body.
Stock cams, just wondering if these injectors will be too big?

I'm assuming Corey tuned the motor as well and he's one of the best. The real issue w larger injectors involves control of the PW at idle. Too big an injector and a smooth idle becomes problematic.
There are big displacement motors running on stock injectors although that doesn't mean they couldn't use more fuel. A determining factor is assessing the injector duty cycle at WOT. Is the injector going "static" in order to provide the proper amount of fuel at WOT?
Rule of thumb is you'd like to be at ~85% duty cycle.

[randy ransome]

I got ya. Yea, I'll just order the replacements from FIC.
Idling problems are what I'm having. Thanks.

[tpepmeie]

Originally Posted by XfireZ51

The real issue w larger injectors involves control of the PW at idle. Too big an injector and a smooth idle becomes problematic.

There is NO risk of idle control with 26 lbers. At idle, the entire pulsewidth is sent to the primary injectors. This is likely well over 4msec, so not even close to the non-linear portion of the injector curve.

If the calibration is modified for 26lb injectors, you will notice no adverse affects.

[tpepmeie]

Bump TTT. Need these gone. Make offer.

[Pete]

Todd,timing timing timing is everything we just went with bigger injectors on one of the big inch FBI Z's.

If tuned for these injectors idle will be fine,LT4's came with 28lb injectors or were they 26lb either way they idled fine.

GLWS
Pete

[tpepmeie]

bump. Nobody needs a nearly new set of stainless injectors for $200. Thought these would go a lot sooner.

[XfireZ51]

Todd,

Is this what you used for the 427? If so, any sense of what the duty cycle was at WOT?

[tpepmeie]

Originally Posted by XfireZ51

Todd,

Is this what you used for the 427? If so, any sense of what the duty cycle was at WOT?

Dom,
yes, these were used in Build 1 of the 427. I think they were around 63% DC per the math. 24ms pulse width x .51 (secondary scalar) = 12.2ms per injector. The datalog I have from the chassis dyno stopped at 6200 rpm.

I don't have the datalog from the engine dyno. But I can say that we were running 12:1 at 7000 rpm/700 chp, but with ridiculously high VE table values. Translated-- I think other components were limiting the fuel delivery, not the injectors.

These injectors *should* be good for:
750 chp @ 80% DC
650 chp @ 70% DC

high 670's was the uncorrected hp from the engine dyno on that day with those atmospheric condition. So, I'd say the DC was in the low 70% range at peak power on that day.

[Jagdpanzer]

Todd,
PM sent
Are both primary and secondary injector tips the same stlye as used in the later 93-95 engines?

[tpepmeie]

yes, later style tips.