An interesting upgrade for some older vehicles.

[NightShade]

So saw a video on Youtube about swapping the injectors from the 4.7l dodge engines to a different one. Well I have been wanting to do it and it was time to change the O2 sensors as the mileage was starting to drop. Well while looking through rock auto I decided to look at some injectors as well since mine have about 200k on them and are probably flowing a little crappy.

Anyway saw what was considered the factory injector for my 03 which is a two hole compared to some of the injectors with 4 holes and what a difference.


Here is the conversion buy an Aussie in a 4.7l jeep.

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He puts some information about the injectors below the video and come to find out what they are selling on ebay as upgrade injectors are basically injectors for an 03 Ford Focus 2.3l... which I was able to pick up brand new for 17.09 each. Ebay is selling used ones with who knows how many miles on them for nearly the same amount.

The vid I will insert is the comparison of the old style injectors similar to what I had compared to the "upgrade" a place sells start it at .45 seconds to see the difference. The old 2 hole looks like a squirt gun compared to the mist from the 4 hole. I am pretty sure that the finer the spray the better the burn will be right?

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Well the 12 hole injectors should be super fine and on top of it all they are working perfectly now based on the trim and O2 sensor readings. The graphs are a little off for their actual value to the readings but the upstream is running .08V to .02V and the downstream is pretty steady around .05V to .06V with the fuel trim around the same as it was for the original injectors which was bouncing near 0 once warmed up. Ran this at about 1500 to 2000 rpm.

 

[adamsredlines]

In theory, but sometimes the injector spray is set up to match the shape of the piston. 4.7 Dodge pistons are pretty basic (no reliefs, bowls or cuts). Assuming your pistons are of the same general shape, should be safe. I know for this reason you have to make sure you get correct year injectors on Cummins motors, as the spray patterns do not jive with the piston shape.

Also be aware that the PSI that Dodge uses is higher than the standard pressure most injectors are rated at. IIRC they run at 55psi vs the "standard" 37.5# that most injector flow rates are spec'd at. If you get injectors that Dodge specs at 40#, they'll likely flow less on other vehicles...and vise versa if you put Ford injectors in a Dodge, they will flow more than Ford says.

 

[NightShade]

Agree but probably more of a problem for direct injected diesel's than gas when dealing with piston shape and such.

Dodge does run higher, I believe my year is 42psi and the newer ones are 49psi. However the manufacturer's tend to rate them all based off the standard so an injector rated at 24pounds will still be ideal if the oem injector was the same or close. The HO motors use a 24pound injector on the 4.7l and the standard is 19 pounds, the older 19 pound ones were under rated though. The injectors can also be adjusted by the computer up to about 20 percent based on the burn being reported by the O2 sensors.

The OEM injectors for the 4.7 are a siemens brand 2 hole with a red band near the tip but even rock auto is selling ones that are a 4 hole injector from SMP and are rating them for years from 2001 to 2007 in the Dakota even though the 2004 year to 2007 year went to a 4 hole standard that from what I read flowed more than the 2001 to 2003 injectors.

I did a lot of research before I pulled the trigger. I think that the O2 and Fuel trim tell the story best though since the trim is low and the O2 sensors are reading right where they should be.

 

[swampratt]

I read about installing the ford injectors into the dodge engines years ago ..
main reason to do so was increased MPG.
My father-in-law has an older 318 fuel injected dakota 2 wheel drive and the thing only gets 15 MPG.

he got it new from the factory .. it is still going strong today but that 15 to me suckes for a FI vehicle as small as that truck.
I tuned my 6000 lb E 150 with a 2 barrel carb and 302" engine to 17.6 MPG and that is pulling a little bayliner.

Not impressed with the MPG of many FI vehicles and I feel it comes down to the fuel not being atomized well.

Think about a warm bed of charcoals that you tried to light off for a second time.
No luck so you spray some charcoal starter onto it.

You see the fluid begin to evaporate and make this white fog.
That is the liquid fuel getting very atomized turning into a fog.

Now take a carburetor sitting on a cast iron intake and an engine temp of 195 degrees.
That iron intake will hold a lot of heat and the fuel must tumble through those rough runners.
Then into some Iron heads .

Yes i ported all my heads and i leave the surface texture very rough.. I also want to introduce swirl when I concentrate on porting .
Now there you have very atomized fuel droplets and really good MPG.

Remember the heavy 1/2 ton long beds. Buddy had one and it was getting like 8-12 MPG granny 4 speed in town driving 90% of the time.
He had the engine rebuilt thinking that was the issue..I told him it was not.

Quadrajet Carburetor and HEI ignition.
He gets it back and the MPG did not change.
He drove it a few weeks.

I went to his rescue and for free put the tune on it.
Now stock little GM cam and the engine did not have any porting or trick things going on.
I lowered the APT adjustment in the carb and pulled the vacuum advance off and dialed in 18 initial timing and 38 total all in by 2000 rpm.. lighter advance weight springs in the distributor.

He called me a couple weeks later and told me i would not believe the MPG it was getting.

I said is it 18. as that was what my other friends suburban was getting when I tuned it the same way.. yes a suburban.

My friend told me it was getting 21.5 MPG...WOW even I was impressed.

I have driven these newer 2013-2014 5.3 LS trucks and MPG sucks.
It must be the fuel is not atomizing.
I stuck my bayliner behind them and expect way worse. like in the 11-12 MPG area.

What gives??? My answer: when you demand more power those injectors dwell open longer and this creates a cooling effect from the extra fuel.
Aluminum heads do not help the situation. even less atomization than before.

Throttle body injection worked ok but the timing curves i feel limited some MPG.
Back in the late 80's i pulled many throttle bodies off vehicles and pulled the feed back distributors and installed old school distributors and stuck a carter AFB or a Q jet onto those engines.. every one picked up a bunch of power and a bunch of MPG.

But as we know power and MPG does not always play nice with the exhaust sniffer.
I have always felt the sniffer was wrong in the way they go about it.
I feel if you get more miles on the fuel being burned you must be putting out less pollutants.

 

[tRidiot]

I read about installing the ford injectors into the dodge engines years ago ..
main reason to do so was increased MPG.
My father-in-law has an older 318 fuel injected dakota 2 wheel drive and the thing only gets 15 MPG.

he got it new from the factory .. it is still going strong today but that 15 to me suckes for a FI vehicle as small as that truck.
I tuned my 6000 lb E 150 with a 2 barrel carb and 302" engine to 17.6 MPG and that is pulling a little bayliner.

Not impressed with the MPG of many FI vehicles and I feel it comes down to the fuel not being atomized well.

Think about a warm bed of charcoals that you tried to light off for a second time.
No luck so you spray some charcoal starter onto it.

You see the fluid begin to evaporate and make this white fog.
That is the liquid fuel getting very atomized turning into a fog.

Now take a carburetor sitting on a cast iron intake and an engine temp of 195 degrees.
That iron intake will hold a lot of heat and the fuel must tumble through those rough runners.
Then into some Iron heads .

Yes i ported all my heads and i leave the surface texture very rough.. I also want to introduce swirl when I concentrate on porting .
Now there you have very atomized fuel droplets and really good MPG.

Remember the heavy 1/2 ton long beds. Buddy had one and it was getting like 8-12 MPG granny 4 speed in town driving 90% of the time.
He had the engine rebuilt thinking that was the issue..I told him it was not.

Quadrajet Carburetor and HEI ignition.
He gets it back and the MPG did not change.
He drove it a few weeks.

I went to his rescue and for free put the tune on it.
Now stock little GM cam and the engine did not have any porting or trick things going on.
I lowered the APT adjustment in the carb and pulled the vacuum advance off and dialed in 18 initial timing and 38 total all in by 2000 rpm.. lighter advance weight springs in the distributor.

He called me a couple weeks later and told me i would not believe the MPG it was getting.

I said is it 18. as that was what my other friends suburban was getting when I tuned it the same way.. yes a suburban.

My friend told me it was getting 21.5 MPG...WOW even I was impressed.

I have driven these newer 2013-2014 5.3 LS trucks and MPG sucks.
It must be the fuel is not atomizing.
I stuck my bayliner behind them and expect way worse. like in the 11-12 MPG area.

What gives??? My answer: when you demand more power those injectors dwell open longer and this creates a cooling effect from the extra fuel.
Aluminum heads do not help the situation. even less atomization than before.

Throttle body injection worked ok but the timing curves i feel limited some MPG.
Back in the late 80's i pulled many throttle bodies off vehicles and pulled the feed back distributors and installed old school distributors and stuck a carter AFB or a Q jet onto those engines.. every one picked up a bunch of power and a bunch of MPG.

But as we know power and MPG does not always play nice with the exhaust sniffer.
I have always felt the sniffer was wrong in the way they go about it.
I feel if you get more miles on the fuel being burned you must be putting out less pollutants.

Wow... that's a helluva dissertation. Care to do a tune on my Tahoe to get me up to 18+mpg? lol I'd be happy as a clam if I could do that! I'm running in the 14s routinely on the highway. Of course, the lift mods @SlugSlinger helped me do (errrr... pretty much did for me, actually ) really killed me. 3 alternators doesn't help much, either!

 

[swampratt]

Those alternators do not pull much power if the accessories are off and batteries are fully charged.

I ran a 2000 continuous watt inverter and a window unit in my van with a TV going and front ac on heading down the highway in arizona and still pulled MPG in the 17's and one stretch got 19+ MPG No overdrive and 350 gears.
that was my 84 ford van 6000 lbs empty.

Mobil synthetic wheel grease mobil synthetic trans and differential fluid and Mobil synthetic oil at that time.
Later changed to T6 rotella.

Here is an eye opener.. I had a spare tire mounted to the front bumber on a cattle pusher rack.
When i removed the spare tire the MPG dropped 2 MPG..I **** you not the tire helped aero drag on the front of that brick.

No vacuum advance 18 initial timing and 35 total on that Ford 302.
3" single exhaust through a 3" turbo muffler.
Air pressure in the tires needs to be checked and maxed out.
My corolla will drop 5 MPG from 44 psi to 35 psi.

All those little things add up.
Not all synthetic oil is the same when it comes to MPG. I tested many.. but today i have not found a decent one they keep changing them on me.
I was running T6 up until a few months ago.

What engine and fuel system in the Tahoe..Is it carbed??

MoBoost runs a dyno tune shop and has asked me a couple times if i tuned my stuff with a wide band..Nope.
Tune the old fashioned way.
Jet down primaries until you get a lean surge at part throttle cruise. then jet up .001" at a time until it is gone then come up .001" to .002" more to be really safe and this puts part throttle cruise in the 14.5 area.
Idle air fuel ratio on these older factory carbs usually falls in the 15-18 area.
Idle AFR can be pretty lean and not hurt a thing.. my van was high 18's and part throttle cruise in the 15 area.

Very lean but long small runners in the 2 barrel intake and all the added timing made it work.
If you run lean you add timing to help it out.

So what do you have and have you put a timing light on it?
Thought about a spare on the front???

 

[SlugSlinger]

Wow... that's a helluva dissertation. Care to do a tune on my Tahoe to get me up to 18+mpg? lol I'd be happy as a clam if I could do that! I'm running in the 14s routinely on the highway. Of course, the lift mods @SlugSlinger helped me do (errrr... pretty much did for me, actually ) really killed me. 3 alternators doesn't help much, either!

The tires are a killer too. They are more un-sprung weight, bigger diameter and a lot more rolling resistance because of the size and design. But they are cool!!

They may be throwing off your speedometer as well by maybe 5-10% depending on how much bigger they are. 14 MPG + 10% correction is 15.4 mpg.

What size are you running now and I can calculate the difference.

 

[tRidiot]

I'm running 275/60r20 right now. Stock size is actually 265/70r16.

However... I am pretty sure I had my tire size reprogrammed a few years back... when I first put on 20" wheels.

An online calculator tells me at 65mph on my speedometer, I should be doing a hair over 70mph actual. This is based on stock, but using GPS on my phone as well as my stereo headunit, this isn't quite right. I actually set the cruise at about 67 to ride at 70. This correlates well with plugging in a 285/50r20 as the original tire, which is what I was running before the lift. So I am assuming that I had the programmer change the tire size at the time. I was having him activate the pin switch for electric fans on my 2004, which weren't factory until 2005.

With those numbers, I should be off by about 4.7%, I believe, which would correct for a mileage of ~15.2mpg, from a reading of 14.5mpg at the dash. However, I know from previous experience that the reading at the dash isn't all that accurate, either. I think the last time I calculated it, it was showing something like 18+mpg, and I calculated based on mileage driven at somewhere in the low 17s. This was unscientific, of course, as it was calculated from full tank to full tank, simply using the pump at fillup to fill as high as possible. But it was a rough guesstimate. I should do that this week, try to calculate actual mileage, since 99% of my driving is pure highway.

 

[NightShade]

Seems like swampratt's method can also be applied to a fuel injected vehicle. Just have to make a heat exchange system to heat the fuel up in the rails. May have to try it.

http://www.science20.com/simple_sol..._gasoline_mileage_now_and_improve_our_economy

Gasoline vaporizes at 140 degrees if you raise the temperature of the gasoline to say 200 degrees the gasoline will vaporize faster in the combustion chamber resulting in a better burn and improved gas mileage. With both of these techniques implemented you will see vast improvement in your overall gas mileage. With fuel injection I heat my gas right off the manifold into the injectors in a liquid state. It's an invention I created out of scrap copper, but anyone can do it. There is no reason you can't double your mileage with a little effort and knowledge.

Some of the rest of the article doesn't do me a lot of good since I have to lug around a set of 50 pound ramps along with a 300 pound power chair in the bed of my truck but heating the fuel is much easier. I figure find a way to extend the fuel line to a point where I can coil a copper or aluminium line around it and run coolant through I can easily heat the fuel up to the engine temp of around 160 to 200 degrees depending on the time of year.

Anyway I think the injectors are helping, ran about 190 miles on 11 gallons (17.27 mpg) fighting a headwind half the way at 75MPH with said junk in the back of the truck. Was getting closer to 15 before with the chair in there and part of it was in town driving which has always sucked with my truck.

 

[elwoodtrix]

Ok gearheads... I need or want a 350 for an 82 4x4 short wide bed with at least 300 HP.... what do I need? I've gotta smoked out 305 currently in it