black88z51

Can someone please tell me if these are original looking OEM injectors 91 Zr-1. Thanks in advance.

Crabs

[QUOTE=black88z51;1588745092]Can someone please tell me if these are original looking OEM injectors 91 Zr-1. Thanks in advance.

Sure looks like the original Delphi Multec.
Hard to be absolutely positive unless you remove the plenum.

'Crabs

A26B

Looks like original to me.

Dynomite

Since we are talking about Injectors......what kind of Injectors are these?
Stock Injectors measure 12-13 Ohms and I am assuming 14 ohms on all the Unknown Injectors?



The stock Injector is on the left and the unknown Injector is on the right.


The little plastic cap ( pintle cap) on the Unknown Injector stays with the injector as installed and keeps the "O" ring from falling off the Injector and inside the Injector Housing.

z06scentair

Cliff,

The orange top injectors appears to be consistent with Ford 19# injectors commonly found in the 302 / 351 of the 80's and 90's

Dynomite

Hi: Thanks Brad for the information.....I was wondering what is the resistance check and flow rates of these injectors (Ford #19)?

I have found these injectors on three LT5s I have restored so far and the resistance of these (Ford #19) injectors in photos is 14 ohms within 1 ohm on all injectors. One set of those (Ford #19) has the pintle cap and another set did not. Some guys remove the plastic pintle cap which is suppose to be left in place during installation (I think on the secondaries).

I have not found one of these injectors (Ford #19) with resistance not within an ohm of 14 ohms. I left one set of (Ford #19) in the restoration of one LT5 and it runs perfectly. I may use a spare set of these injectors in a 1991 LT5 I am now restoring.

z06scentair

Cliff,

I'm not sure of the flow rates of these 19 lb injectors. You are correct about the pintle cap it should remain so the atomization is correctly distributed.

All I can say is that once we were reaching the 300 hp mark on the 5.0L motors back in the day these injectors were about maxed out on DC at 90%

A quick call to John @ FIC should be about the answer your questions about flow rates of the FMS 19 lb injectors.

770-888-1662 super nice knowledgeable guy!

Dynomite

Ya but....was that not for 8 injectors?

z06scentair

Guessing DC?

Yes that was for 8.....Ford never made enough HP to need the extra set!

hiperfman

The ones on the right look like the FIC rebuilt injectors I just replaced on my 91 ZR1.

lorne #1748

Dynomite

Just guessing here but this is what I am thinking......

I am assuming the Ford #19 are 19 lb injectors rated at a fuel pressure of 39.15 psi.....read that somewhere



Horsepower = (Fuel Injector Rating)(Duty %)(Quantity of Injectors)/(BSFC)

If we assume Brake Specific Fuel Consumption (BSFC) of .50 lbs of fuel per hour per horsepower......
The Injector Rating required for 500 hp (80% duty cycle and 16 injectors).....
We would get 19.53 lbs/hr for each injector is required for 500 horsepower.

We have for the Ford #19s Injectors a Fuel Flow Rate Increase since the Ford #19s are rated at 39.15 psi Fuel Pressure and we operate at 43.5 psi Fuel Pressure. We have square root of Actual Pressure/Rated Pressure or square root of 43.5/39.15 = 1.054 x 19 lbs/hr = 20.03 lbs/hr actual flow rate of Ford #19s (at the higher Fuel Pressure of 43.5 psi) which is greater than the 19.53 lbs/hr required for 500 hp.

Another way of looking at the Ford #19 Injector Capabilities......
For the Ford #19s in an LT5......Horsepower = (19)(1.054)(.80)(16)/.50 = 512.7 hp

As a comparison I have calculated the use of RC SL4 205s.....
I use RC SL4-205 injectors in a 1991 500 horsepower LT5 which RC Injectors are 20 lb rated at a Fuel Pressure of 43.5 psi.
You would use RC 225s for 650 hp or more.



Horsepower = (Fuel Injector Rating)(Duty %)(Quantity of Injectors)/(BSFC)

If we assume Brake Specific Fuel Consumption (BSFC) of .50 lbs of fuel per hour per horsepower......
The Injector Rating required for 500 hp (80% duty cycle and 16 injectors).....
We would get 19.53 lbs/hr for each injector is required for 500 horsepower.

There would be NO correction for Fuel Pressure Differences on the Injector Flow Rate since RCs are tested at the same pressure we are operating with in the LT5 (43.5 psi Fuel Pressure). 20 lbs/hr actual flow rate of RC 205s is greater than the 19.53 lbs/hr required for 500 hp.

Another way of looking at the RC 205s Injector Capabilities.......
For the RC 205s in an LT5......Horsepower = (20)(1.0)(.80)(16)/.50 = 512 hp

Bottom Line......the Ford #19s are equal to the RC 205s as used in an LT5 Application (16 Injectors) with 43.5 psi Fuel Pressure available.

See Restoration of the Injectors

z06scentair

Cliff,

Great Information looks like you've done your due diligence.