fuel injectors for a stroker

[scase86]

hey everyone...I have been seriously considering building a stroker out of my 4.0 and need to know what kind of injectors to use. I am anticipating the stroked engine to be around 4.5 liters and I already know I need to use 24# an hour ford injectors. since this is budget minded I was wondering If I would be able to score these injectors in any bone yard fords, IE 5.0/5.8 fords or possibly a v6? having them serviced afterwards will still be 100+ dollars cheaper than a new set so im not too worried about the who used issue. so all in all, does anyone know what years/engines I can find the right fuel injectors? thanks

 

[langer1]

I don't know which ones you need but check eBay for some good deals used and new.

 

[Gil BullyKatz]

http://www.fiveomotorsport.com/Injector_Sets.asp

 

[scase86]

ok sweet I actually found a set of fuel injectors to use. They are the ford racing 24#/hr units. mu new question is, at what fuel pressure are these to be used? I believe stock is 39psi, do I need to boost the fuel pressure at all? thanks

 

[cardboard]

Fiveomotor sports is the place to go!!!

 

[old_man]

I am running the 24# injectors on my 4.7L. Here at 5,000 ft elevation, I actually was running a touch rich and put on a MAP adjuster. I scored my injectors as pull offs on ebay. I got a set of 8 for around $50.

 

[Dr. Dyno]

ok sweet I actually found a set of fuel injectors to use. They are the ford racing 24#/hr units. mu new question is, at what fuel pressure are these to be used? I believe stock is 39psi, do I need to boost the fuel pressure at all? thanks

No. I still have the stock 39psi regulator on my '92 XJ. The thing I did to increase fuelling, apart from the Ford 24lb injectors, was to build a MAP adjuster and I have it set at 5.15v. A/F ratios and emissions are excellent.

http://www.angelfire.com/my/fan/stroker.html

 

[scase86]

This question is geared toward DR. dyno...I am thinking about building a MAP adjuster, I would like to know how important having the small trim pot rated at 1000ohms is. I actually found one rated at 25 ohms that would work better for what I have planed, but I figure there was a reason for running so much resistance on that pot. I figure since yours needs 15 turns to adjust completely it would probably be more accurate than one running lower resistance? thanks

 

[old_man]

Sorry for butting in here but I'm an elecrical engineer and have designed and built several MAP adjusters. The values are fairly critical if it is the standard 3 terminal regulator circuit. The values are what set the initial adjustment range. 25 ohms is so far off that the circuit probably will definately not function as designed. Plus or minus 10% would most likely work, but beyond that all bets are off.

 

[langer1]

You don't change the fuel pressure, you can build the MAP adjuster, what that does is change how long the injectors are delivering fuel.

 

[Roll-over]

This question is geared toward DR. dyno...I am thinking about building a MAP adjuster, I would like to know how important having the small trim pot rated at 1000ohms is. I actually found one rated at 25 ohms that would work better for what I have planed, but I figure there was a reason for running so much resistance on that pot. I figure since yours needs 15 turns to adjust completely it would probably be more accurate than one running lower resistance? thanks

um... ok....



um.... sorry, you threw me for a second... A 1kohm Pot adjusts from 0 - 1000 ohms, 0 - 25 for the 25ohm pot. I havent seen the circuit you're building, but the pot is probably part of an RC feed for a voltage regulator... subbing in a 25ohm (depending on the regulator you are controlling) will only give you either the very high or very low end of the output scale. I agree with the engineer, follow the parts list on the schematic!

 

[Dr. Dyno]

This question is geared toward DR. dyno...I am thinking about building a MAP adjuster, I would like to know how important having the small trim pot rated at 1000ohms is. I actually found one rated at 25 ohms that would work better for what I have planed, but I figure there was a reason for running so much resistance on that pot. I figure since yours needs 15 turns to adjust completely it would probably be more accurate than one running lower resistance? thanks

Tom's already answered the question very eloquently.
Copy my MAP adjuster so that you'll know it's guaranteed to work.

http://www.angelfire.com/my/fan/MAP_adjuster.html