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chadjans
06-06-2005, 09:19 PM
A LONG time ago there were a few guys running some ford racing fuel injectors on their 4.0l. I do not know what size they were or if they got the impedance right to match the chrysler's impedance. Anyone have some bookmarks they want to share on the swap?

Chad

Swamp boy
06-06-2005, 09:34 PM
I am running those on my 5.2 but I dont have a book mark.. I will try to find them if you think they will work for the 4.0..

Carl

LouisianaZJ
06-06-2005, 10:12 PM
I have the ford 5.0 24lb injectors on my 4.0L

the previous owner put them in

I cant feel a difference over a stocker in response, and he said he noticed little change

POINTLESS (unless you are replacing them anyway, they are supposed to have a better spray pattern for better mixing or something)

dasVettemeister
06-06-2005, 10:55 PM
Let's see, how do I put this delicately..... Putting bigger injectors into an otherwise stock engine is STUPID, STUPID, STUPID!!!!!!!! The stock injectors in most fuel injected engines these days are running at approximately 80-85% duty cycle, IF THAT! This means that there is plenty oh "headroom" left, and if you have bolt-on mods (header, throttle body, CAI) I still doubt that you'd exceed a 90% duty cycle on the stock injectors. Bigger injectors are only going to degrade your idle and low rpm performance; ESPECIALLY at the fuel pressure that is run on Jeeps Even with intake revisions and an exhaust system, there is no need for bigger injectors. It will only cause you to lose low and mid-range torque. Torque is the only thing that 4.0 has going for it. The only time you should be even thinking about bigger injectors is if you have more displacement, ported head, and a bigger cam. Then, and ONLY then, would there possibly be a need for bigger injectors.

I read your other thread about putting nitrous on the motor. (read my reply) You seem pretty bent on getting more horsepower out of your 4.0. If this is the case, I have one, and only one suggestion: Get yourself a V8. THE 4.0 IS NOT A HORSEPOWER ENGINE!!!! IT NEVER WILL BE!!!!

chadjans
06-06-2005, 11:10 PM
I was thinking of doing it all at once:

Stroker kit
nitrous
and bigger injectors

Yeah I know it may be a pipe dream, just thinking out loud.

Chad

dasVettemeister
06-06-2005, 11:15 PM
I was thinking of doing it all at once:

Stroker kit
nitrous
and bigger injectors

Yeah I know it may be a pipe dream, just thinking out loud.

Chad

Stroker kit and injectors would work. plan on porting the head, adding bigger throttle body, and a better exhaust sytem including a header. I would also plan on a new intake due to the fact that your stock one would become your limiting factor. Forget about the nitrous.

After stroking the thing and adding all of the peripherals, you'd have so much money into the engine that you could have 3 V8's.

TrojanMan
06-06-2005, 11:23 PM
Phew, you just opened up a can of worms!

Long story short, you'll be happy with just a stroker. If you just stroke it you're looking at about 1200-1400 dollars. However if you want to add some nitrous to it, you're looking at 500 dollar pistons, special prep work done to the block, etc etc. Ford 24 lb injectors are a perfect match for the stroker.

For the best info look around on the SpeedFreaks section of JU. Also read up here : http://www.jeep4.0performance.4mg.com/stroker.html That's Dino Savva's site, he is the god of the 4.0 engine. He's helping me with my stroker.

By the way, the ford 24 lb injectors are plug and play in the 4.0.

Swamp boy
06-07-2005, 02:57 AM
Let's see, how do I put this delicately..... Putting bigger injectors into an otherwise stock engine is STUPID, STUPID, STUPID!!!!!!!! The stock injectors in most fuel injected engines these days are running at approximately 80-85% duty cycle, IF THAT!

I put in the injectors after getting my head Job.. (snicker snicker..)and bored throttle body,new fuel pump and fuel pressure regulator and flowmaster and ........ You get the point...
You are correct pretty senseless without doing anything else...But if you are doing it in conjunction with other things it can be an improvement and lets face it . The 4.0 needs all the help it can get... :smt003

TrojanMan
06-07-2005, 03:27 AM
Injector flow rate (lb/hr) = [Expected HP x 0.5 (BSFC)] / [no. of cylinders x 0.8 (injector duty cycle)]

The actual injector flow rate from each injector depends on the fuel pressure (FP) in the injector rail. Most injectors have rated flows at 43.5psi fuel pressure. The actual flow rate from each injector is:

Actual injector flow rate = Rated injector flow rate at 43.5psi x square root of (FP/43.5)