Is running 19# injectors on a 350 going to cause any problems? I have the fuel pressure set to 32 PSI and I'd like purchase new 21# or 24# accel injectors, but I've got to wait awhile!

 

Check out my thread........right under yours. I asked the same thing. Basically, get the correct injectors.

https://www.thirdgen.org/techbb2/sho...hreadid=331350

 

No problem. just bump up the FP.

 

I've bumped the FP to 32 PSI is that enough or should I go higher? It seems to run real nice, but I haven't gotten it out for a test run yet! Dam Rain! Anyway It's a completey stock engine, but I've got some add-ons! Exhaust, K&N's, Headers, Hi flow Cat, Hypertech chip, etc.....

 

3 bar is 43.5 PSI, and that is where the factory injectors are rated at. I would start there, and move up in pressure if need be. At 43.5 the #19s will flow 19lb hr.

 

I'd be concerned something was wrong with my gauge... Technically, the engine shouldn't run very well with 3-bar 19 lb/hr injectors running at 32 psi!

However, if you bump up the fuel pressure they should be fine. Doing some quick ratio comparison math, you should run your fuel pressure at 50 PSI to get 22 lbs/hr out of a set of 3-bar 19 lb/hr injectors

 

FWIW I had a stock 145K L98 running Ford 19s. With 48psi (vac off) and no tuning, she pulled great (enough to finally finish off the 700R4) and hit just under 28mpg on a trip to Tahoe. The rest of the mods consist of the Holley AFPR and a catback. 3.23s in the 10bolt. HTH

K

 

I reused my 19s from my old 305, and used them on my old 355, and ran 13.00s. If I went up past 48 on the FP, the car ran real rich, where it smoked out the tailpipe.

 

So you guys didn't need to repro the computer? But you do need an AFPR correct?

If so than I am worry free.

 

Back when I had my old 355, I did not even think I could reprogram my own proms. I had an ASM mail order prom, but even so, with an increase in FP, the 19s supplied plenty of fuel for my 355.

Yes, you will need an AFPR, and a FP gauge.

 

22# injectors will barely support 300 HP at 50 psi and an 80% duty cycle. Check out this chart. You will have to scroll down and insert the data in the blocks to get the size of injectors needed. http://www.rceng.com/technical.htm

A BSFC of around .50 would be good for a standard motor. A built street motor with good heads can use a BSFC of .45. A race motor can use a BSFC of .40.

 

It's just like I was saying in the other thread. If you are bump up the psi on a 19# injector, you will make it go static and will run lean. A static injector is just open, and will not be able to flow any more fuel than at wide open.

As I stated, the 19# injector will work in the lower RPM band, but when you start revving it up into the high, you will send the injector into static. Sometimes they don't come out either, meaning wall wash, new injectors, and hopefully nothing else worse.

I'm not saying that you're car is going to fault no matter what, but it will not be making complete power and could be wearing itself down faster if not properly setup.

 

Also it is not good to go above the 80% duty cycle as the injectors "may" become erratic in operation above that range. The above post is dead on.

 

it is a problem. I had a 350 put in and i hadd the 19lb injectors from my 35. it runs real lean no matter what u set the fuel pressure at and that means the engine runs hot and thats no good. get slp 24lb injectors $100 a set

 

It can be done, and can be made to run, but the proper method is to install the larger injectors - THEN program.