Originally Posted by lastrights

i voted 5 stars for this thread, lots of good info !

Originally Posted by Maxx_Magnum

QUICK QUESTION: Which one of these do you think is the correct length?? The new ones are clearly longer than the old ones, but these are what Canadian Tire's stupid parts lookup book called for for my year and motor... I don't know if maybe the old ones were shorter than they shoulda been, or if they are the proper length and the new ones are just the wrong ones...



Oh, and Aim, is that for real? I might try doing that... I would for sure unless I have to go back to exchange the plugs tonight, I'm about 45 mins away and I need the truck in the morning... ^&*^%*% crappy tire lol

Originally Posted by cmckenna

AIM,


Now, while on the subject of fuel injectors, a good friend of mine who rebuilds those things has the test equipment to test injectors. What was starting to us was the fact that the 4-orifice injector nozzles that we tested did NOT spray worth s-h-i-t. In our tests, we liked the single hole pattern that was produced by Ford Blue Tops. I believe those were single orifice design but, I may be mistaken. This was last year in fact so, it wasn't too long ago.

CM

Originally Posted by aim4squirrels

EDIT, too long winded to reply to you VW,


Yes, but moving the outer housing out of alignment with the inner ring causes a change in fuel sync, which is when the injector fires. Any greater than +/-20* and the PCM loses fuel sync and the engine won't run, or runs like crap. Because the disty runs off the cam, which is turned by the crankshaft via the timing chain, any slack in the timing chain will cause the fuel sync to bounce around and the engine won't run as smooth.

My understanding of fuel sync is this:

The fuel sync determines when the injectors fire in relationship to the opening of the intake valve. From the factory, injectors are set to fire at 0 fuel sync, and this is with the intake valve closed. Advancing fuel sync fires the injector even sooner and seems to run a bit better on a street car, even as much as +6 to +8. Retarding will wait on injector firing and may make it line up better with the opening of the intake valve. This seems like a good idea, right? It's not on our engines and here's why:

Our injectors suck for non-boosted applications. The one pintle design is a pencil beam of gas as shown in this video:

http://www.youtube.com/watch?v=Emnax...eature=related

Ours spray like the 3rd one.

This is bad because the gas doesn't atomize well in N/A engines. It may very well be favorable for a boosted application, as the fuel is already being beaten into a pulp by the boosted air, and when timing events get so small at high RPMs, you're getting the charge into the cylinder as quickly as possible, which is of benefit at 6000K+RPMs

But for us normal folks, it sucks as the gas stays liquid. Liquid gas does not burn correctly in the combustion chamber and causes all sorts of carbonizing on the pistons, valves and down into the catalytic converter.

I took the heads off the engine just this last winter and I **** you not, I scraped as much as an 1/8th an inch of carbon off the piston tops, and this was after I ran a tank of chevron fuel concentrate, and a can of Mopar Combustion Chamber Cleaner thru the engine. I was blown away.

The reason the injectors fire when the valve is closed is because the valve gets hotter than the rest of the cylinder because it's thin steel compared to the cast iron cylinder head and block, and it's isolated from any cooling channels that run thru the head and block. The hot valve actually helps to vaporize the liquid gas and atomizes it better before the charge enters the cylinder. Advancing the injector firing lets it sit on the valve a bit longer too, which is why folks seem to see a slight benefit by twisting the disty advanced just a hair. Still, this will lead to carbon deposits on the intake valves, which is still bad.

I'm convinced the only good solution is to dump the stock injectors. I just ordered a set of the Bosch 3's and am going to test it out. I anticipate the engine should idle smoother, (especially on cold start up), accelerate better and faster. If my a/f gauge is reading correctly, Hemifever can dial in the a/f ratio to match the stock injectors via my SCT and I'd imagine there will be a fuel savings to be found if I drive it the same as I currently do.

It's interesting to note that Chrysler switched to a 4 hole design for the 3.7L, 4.7L and 5.7L engines. I've heard rumor that the 2002 4.7L engines flowed the exact same lbs/hr as the 5.2s and 5.9s from 1996-2001, but were a 4 hole design and can be swapped (EV6 connectors), however, I have not found the lbs/hr data on the 2002 4.7L to verify this.

Originally Posted by Maxx_Magnum

I was thinkin about doin up a diy on this little task, and I was planning to include all this info as well... I have enough pics and info from here to do it

If I'm quick, maybe I'll get it done before purpl does his

Originally Posted by CPTAFW163

Here are the GEN3 injectors that you want:
http://www.fiveomotorsport.com/product-search/?v=8305

I did a quick search for the 4.7 injectors:
http://www.fiveomotorsport.com/product-search/?v=7607

You can probably call up Bruce at Five0 and ask him what the lb/hr rating is. Weird thing: They are almost the same price as the GEN3 4 hole injectors. So I am guessing that they are good injectors. They are flow matched for 44PSI rating, so with our trucks, they will flow 1-1.5 lb/hr more since our trucks run 49PSI.

Originally Posted by CPTAFW163

I have the ford blue tops. They are 4 hole injectors. They have F1TE D9A written on the side (Also F1TE D9A. I owned 2 different sets of Bosch 4 blue tops).

They both have the Blue Oval on them and say Ford Motorsports on them.

Originally Posted by PurplDodge

It took me less time to change my plenum than it did for you to change your friggin spark plugs!

VW&Dodge, I love your signature!