Can't remember who had done it up (Eddie?), but I wanted to pass it along to a friend and can't find it now in the Tech Articles. Anyone have a link to it?

 

http://www.bigblocksix.com/eddie/injectorswap/

The swap is really worth it!!!

 

Others dispute the advantages of this swap on a BONE STOCK 300.

Anyone done it on a BONE STOCK engine ??

 

The only thing done on mine was removed the cats, and smog system. I thought the power was night and day difference, But there was over 250,000 miles on the stock injectors.

 

How much did the swap cost you ??

 

i havent done it yet but i got a fuel pressure gauge from auto zone for $36 injectors of of ebay for $1 (plus $10 shipping) and an adjustable fuel pressure regulator is $54.95 from summit Summit.
so about a hundred bucks if you get a good deal on injectors.
im still searching for a throttle body ofof a 302 or 351 the people at my local junk yard are dick heads.

 

The complete cost with new injectors and fuel pressure regulator was about $150, I found a website that sold 19# Mustang take offs for $90

 

What's the website?

 

I didn't swap injectors on my truck until after the exhaust work and there is very little difference in power, just better throttle response. I gained about a tenth of a second in the 1/4 when I did the swap, which is about 3 or 4 hp at the wheels. That isn't even enough to call it a gain, it could have been caused by anything from the wind to shifting better.

 

can i use used 19# injectors off any 92-96 351 v-8 or is this a bad idea? my local Ford dealer wants $100 each for injectors.
steve

 

jjs448 said:

I have one extra 302/351 dual 50 mm throttle body lying around.

 

The swap is a waste of time and money......
Dropping the fuel pressure and increasing injector size will deliver the EXACT same amount of fuel...NO Horsepower gain there.
X amount of fuel equals X Horsepower
You must add fuel to get more horsepower.
SilverStreak posted that the exhaust on his truck will ""Burn your eyes at idle"" A properly tuned engine will not do that. the computer cannot control The larger injectors, dumping too much fuel in the engine

Simply replacing injectors with 100,000 miles on them will deliver a noticeable power increase as the older ones are usually gummed up. The 300 is notorius for this (Heat)
Do you want a REAL performance increase???
Install the 19LB Injectors and use the stock fuel pressure regultor. Port and polish the head, Get a custom chip burnt for the changes...
Now you will see an increase
the swap of the injectors and the regultor is meant to ""fool"" the computer. If your going throught the trouble do it right>>>>>

ftwfred

 

Not necessarily a waste, not necessarily a gain. it all depends on what you're doing.

At the time Eddie started this experiment there was some question as to whether the fuel system limited the performance of the 300. The feeling was that perhaps the knock sensor was pulling out timing at WOT in response to a too lean condition and that a larger fuel supply would eliminate this. There was also the question of whether the stock injectors provided enough excess fuel at tip-in to maximize throttle response. Again larger injectors seemed like an answer. What the experiment showed was that there was little or no gain in HP at WOT but there was a noticable gain in throttle response.

The stock fuel system with 14# injectors operating at high pressure and putting out about 17.1# each is good to somewhere in the range of 164-192 HP. If you modify the engine beyond those limits you must increase the fuel supply. The stock regulator for the 300 is already at or near the upper limit of most adjustable regulators so you cannot gain anything there.

Unfortunately, the 19# injectors running at the pressure of the stock 300 regulator put out about 23.5# or enough fuel for 225-264 HP which could overwhelm most moderately built engines. The 19# injectors running at their rated 39 PSI provide enough fuel for 182-214 HP which will support most mildly modded engines nicely. The adjustable regulator provides two functions. First, it allows you to tune the fuel pressure and thus the thruput to the modified engine's requirements. Second, because of the proximity of the fuel rail to the exhaust manifold, the 300 has some issues with hot re-start at lower fuel pressures. The adjustable regulator allows you to bump the pressure if this becomes a problem.

If you have a speed density controlled 300, you're going to need to re-program the PCM or add on a piggyback chip somewhere aroung a 12% increase over stock because of the limits of the air/fuel/spark maps built into the PCM and the limits of the PCM's adaptive strategies. That would be approx. 168 HP. So if you have to do PCM surgery anyway, you can have it modded to support the bigger injectors.

 

Inreality I should replace/hop up the head, exhaust, PCM along with injectors to create more power and this could posibly damage the motor. This makes me think of my original idea to swamp out the motor for a 351.

My300 has 153000 miles and is in perfect condition (Mobil 1 10-30, and very regular maintance) execpt it just isnt fun and it has been that way sence mile 1.

on another note the E4OD in this vechile has never pleased me. it has always clunked into gear sense it was new. I rebuilt it and the problem still exist. Plus the MLP sensor goes bad every couple of years - is this normal?

Thanks for our replies