i figured i would post this here,cause its the newer 5.2 magnum in my 93 d150.
does anyone know which injector is better, the single hole discharge?? or the 4 hole discharge?? thank you

 

4 hole injector is far superior to the dino 1 hole. The more atomized the fuel is sprayed the better the burn.

 

Does anything else have to be taken into account when "upgrading" to the 4 hole? Is it just a straight swap in?

Thanks

 

Match the flow rate of the OEM injectors to the new injectors.

 

Study long and hard before you pull that particular trigger..

Some injectors are rated at 39psi.. some are rated at what seems to be the industry standard of 43.5psi.. we push 49psi on our fuel rails.. you can't just look at the delivery and figure you're okay..

I run FMS 22#r's.. they are rated to deliver 22# at 39psi.. I replaced the 'red' 22#r's with these, and ran pig rich.. I had hemifever cut me back 6% to curve the fuel.. the red injectors are 23.5#s at 49psi, though only 22# at 43.5psi..

To make matters worse, the characteristics of the spray change at pressures differing from the pressure they are designed to use.. you may have a perfect cone of spray at 43.5psi that turns into a stream at 49.. or, a pour..

There is even more to be concerned with... Two injectors rated for 22#'s at 43.5psi may not behave the same at higher pressure.. one may dribble 24#, the other may squirt 26#, though they deliver what they are 'sposed to at the rated pressure..

Yet another concern: a round lot of injectors may be made, of say 400.. enough to outfit 50 V8's.. the first one and the last one may be delivering pretty different flows.. they are rated side by side to get 8 of the injectors that match flow the closest packaged together.. this is important, because:

Your engine doesn't look at each cylinder.. it just knows if the entire bank (on a cali rig) or both banks (federal rig) are producing the proper a/f ratio.. which means, one cylinder may be starving lean, and another fat as a bear, and you won't know until you pull plugs after a while of running them, and inspect them..

I'm all for better designed injectors, but it is expensive, and the gains are minimal.. you CAN fool with your fuel sync and get better results than you can with stock injectors, because you don't need the back of a hot valve to atomize it as much with four holers as you do the streamers, but even then, its not a huge gain..

I rec you keep the stockers.. just my opinion..

 

thanks guys,i'll keep searching for info before i make a choice on this.

 

I am kinda torn on single hole 'pencil beam' injectors, vs. the cone-spray fellers. It's my under standing that injector pulse is timed, and aimed... so the 'beam' hits the back of the rather hot exhaust valve, which flash boils the gas, and incidentally helps cool the valve. I don't know that just upgrading the number of holes on the injector does anything at all for performance/economy or valve longevity either for that matter.

I would dearly love to see some dyno numbers with JUST changing injectors.

 

The gain I spoke of was more economy based.. I don't think there are any power gains with them at all.. its possible to retard the fuel sync a few degrees and make better use of the spray is the plan.. how well that works out, I don't know, but that's the plan..

 

I would think you would want to advance the injector timing a bit? So air is already flowing into the cylinder. That way, it doesn't get a chance to 'settle out'.

Edit: Retard. You are correct sir. You want the injectors to fire LATER.

 

Here is a video were he raises the fuel pressure on the Bosch injectors up to 120psi and they did not turn into a stream like you say they would.

http://www.youtube.com/user/rbanner1.../2/7oTirEZNRw8

What is the # of the EV6 22's you put in?