I have a 1995 f-250 with 5.8,I'm looking to put a performance cam in my freshly rebuilt engine. Is there a cam any one could suggest for a liitle more get up and go? Oh I have headers , cold air intake , electric fan , pollution pump elimination kit, also purchased a set of 24cc injectors instead of the stock 21. I need a cam that will run good with the bigger injectors.

thank josh
does anyone know the
stock HP and how is the
best guess I will have when complete.

 

There is an engine specific section of the forum and you would probably get more info there, but off hand I would say this if your truck is not MAF, then converting to that would be a must...either that or programing your computor.
And yes there are cams out there that will make the truck "get up and go" (I assume you want low RPM torque). Look for a RV cam.

Once you start changing things like the cam and injectors and what not you really need to know EXACTLY what you are doing or else the end result will not be a truck that runs well and gets up and goes.

 

I here Comp Cams 35-255-5 is a good one. 351W with SD computer. I have not heard this cam in action but it should make difference.

 

Stock injectors are 19lbs.
24lb injectors won't work well with the factory computer, and unless you have done major upgrades(heads and intake) you don't need them.
That should also be a roller motor, so the Comp Cams 35-349-8 is a good upgrade.
That engine was factory rated at 210hp, but the exhaust severly restricts it so you should pick up 10-20hp with a decent aftermarket system. With the cam you could see another 10-20 peak HP, but the biggest difference will be in low to mid rpm torque.

 

what would I need to do to make the 24 cc injectors work good.

 

Alot.

And if you have to ask, then thats a good sign that probably should not be making mods like this.

 

I may not know every thing but i got these injectors out of a 1989 bronco with a 351 the engine was a reman stock except headers and it ran ok with the timming advanced it did smoke bit do to running a little rich. So I was hoping to cam it maybe port and polish the heads have a chip burned for the computer. The engine in the bronco is still running ,but I woulod rather use my engine seeing how I just rebilt the lower half. I have the knowledge I was just looking to see if any one has used them.


thanks josh

 

The 95 is mass air isnt it?

 

If the truck is mass air, and you get a proper chip burned buy a dyno tuner(not mail order), then you can make the 24lb injectors work. But the fact remains the stock heads and intake will not flow enough to max out the 19lb injectors.. even with a cam upgrade and port/polish job, so it's all for not really.

 

Im old school so I have to ask, Does going to bigger injectors the same as going to bigger jets in carb. If so what would be the equal to running size 60 jets and changing to 70 jets. I know the cfm does not change but your putting in more gas per air ratio. The cam change will let more air and gas in. I see why one would think to up the injector size. The old way is more user friendly.

 

Well.. putting more gas in than the motor needs is just as bad for a carb'd or EFI engine. If the motor runs good without lean spots on 60 jets, the 70 jets are doing nothing but lowering your fuel milage, and accelerating cylinder wear. When you modify a carb'd motor you have to change the jets, because it has no way to self correct. That's not the case with EFI...

An EFI motor by definition has the ability to vary the amount of fuel it delivers all the time.. real time, because of feedback mechanisms like the O2 sensor in the exhaust. The system's design goal is optimum air/fuel ratio at all times, so it automatically compensates when you do something to the motor to make it flow more air.. like put in a cam or add a nice high flow exhaust. The 19lb injectors will support about 300hp, give or take, and that's about all you can squeeze out of the factory heads anyway, so you don't need to change injectors to get there. Different injectors will just mess up the calibration and limit the range of adjustability for the motor, because the computer now has to throw in a big correction for most of the operating range. But it is only capable of so much correction, so typically the motor will run pig rich, idle poorly and perform badly.

 

Thanks for explanation Conanski. So my stock 93 351 will adjust itself with the right air/fuel mixture with a cold air intake and open exhaust? As far as jets were concerned, we went bigger after reading plugs after a 1/4 mile run. Too lean.

 

Yes.. there is plenty of adjustment range withing the stock system to handle these relatively minor changes.

This jets question is concerning another motor or the 351 EFI motor above?

 

thank you for all the help. i will just have to do some trial and error. i sure i will have it running tip top in no time.