TBI injectors

[4X4HIGH]

Does anyone know the lb. hr. rating on injector number 5235231 from a 1990 454? I've found conflicting info on this, some say 75 lb. hr while others say 90 lb. hr. Oh well, even if no one here knows i guess i'll find out soon enough as i sent 2 pairs of them out for cleaning and flow testing today.

I'm really hoping they are 90 lb. hr because that's what i'm going to need for my new engine.

 

[dyeager535]

These guys say 85#:
http://www.fiveomotorsport.com/Injector_SetsGMTrucks.asp

??

 

[4X4HIGH]

Well my injectors are on their way back to me, i'm guessin i'll get them back after new years. Guess i'll find out then exactly what they flow and i'll post the info here for anyone else who may be curious.

 

[crash81]

These guys say 85#:
http://www.fiveomotorsport.com/Injector_SetsGMTrucks.asp

??

just looked at there site and they say the cop car injectors for the 5.7 are 85lb but everyone i researched say they are 68lb i wonder who is right?

 

[dyeager535]

No clue. Seems odd they've got that much convoluted info out there, there are enough variables out there, thats for sure. (running changes, different manufacturers, rebuilds flowing more, etc)

 

[4X4HIGH]

Ok, got my injectors back today. I now have the flow rates for them. As it turns out TBI injectors (at least through www.witchhunter.com) are tested at 20psi fuel pressure. This is where all the descripencies come from i think. At any rate i sent in (4) 454 injectors part number (GM5235231) to be cleaned and tested. Here are the results.

Injector # (1) 1068cc/min = 101.71 lbs/hr
Injector # (2) 1056cc/min = 100.57 lbs/hr
Injector # (3) 1065cc/min = 101.42 lbs/hr
Injector # (4) 1053cc/min = 100.28 lbs/hr

Now my truck has been running at 13 psi so that brings my injector lbs/hr down to the following specs.

Injector # (1) 82.00 lbs/hr
Injector # (2) 81.08 lbs/hr
Injector # (3) 81.77 lbs/hr
Injector # (4) 80.85 lbs/hr

For anyone else wanting to convert from a given pressure and rating to a new pressure and find the rating here is a spread sheet i ran across. http://personal.ecu.edu/hrb0312/fuelconversion.xls

 

[southernspeed]

Ok, got my injectors back today. I now have the flow rates for them. As it turns out TBI injectors (at least through www.witchhunter.com) are tested at 20psi fuel pressure. This is where all the descripencies come from i think. At any rate i sent in (4) 454 injectors to be cleaned and tested. Here are the results.

Injector # (1) 1068cc/min = 101.71 lbs/hr
Injector # (2) 1056cc/min = 100.57 lbs/hr
Injector # (3) 1065cc/min = 101.42 lbs/hr
Injector # (4) 1053cc/min = 100.28 lbs/hr

Now my truck has been running at 13 psi so that brings my injector lbs/hr down to the following specs.

Injector # (1) 82.00 lbs/hr
Injector # (2) 81.08 lbs/hr
Injector # (3) 81.77 lbs/hr
Injector # (4) 80.85 lbs/hr

For anyone else wanting to convert from a given pressure and rating to a new pressure and find the rating here is a spread sheet i ran across. http://personal.ecu.edu/hrb0312/fuelconversion.xls

Interesting. Good info.