Engine change question

[Seagull81]

I have been thinking about changing my 302 (19 lb injectors) for a 347 (24 Lb. injectors). I was wondering if I have to change to another computer or buy an aftermarket chip.
Thanks,
Steve

[Gaz64]

Steve,

I'd say the engine increase being not as large as the injector increase will need a reflash or eeprom change.

[olddog]

Depending on the Hp of the 347, 24 lb/hr injectors may not be big enough.

If you change the engine displacement or the injectors the computer need to be updated with the correct information.

You need to know what ECU you have for starters and if it uses a mass flow sensor or Manifold Absolute Pressure (MAP).

[Seagull81]

Everything is out of an '89 Mustang. It is mass air with a 70MM TB. My 302 has a '93 Cobra intake with 24 lb. injectors (MAF calibrated for 24s). I thought about using that intake on the 347. I assume I will also need a 155 fuel pump. I'm not in a big hurry as I am gathering parts. Do I need to upsize the fuel line or change the fuel regulator?

[Dwight]

I have a 354 (same as 347, just .070" more stroke) and it make 480 - 500 flywheel hp. 402 rear wheel and 422 tq.
First question is how much hp do you want to make?


I have a 90 mm MA cal for 24 lb injectors, 36 lb injectors, Keith Craft Brodix heads and a Keith Craft / Comp cam.
I have an SCT chip which make the 36 lb injectors work with the 24 lb mass air meter. Well, the chip makes it all work together.

First you decide how much hp (money) you want then you pick the parts that will work together to give you that hp.

For 450- 500 hp you need 80 mm MA, 80 mm intake, 185 -205 heads and a cam to match.
1 5/8 or 1 3/4 exhaust headers. Don't forget the side pipes, their are the largest killer of hp in a Cobra.

Best money I spend was with Keith Craft on the heads and cam. I gained 80 hp.

You need a fuel pump to match the hp. Fuel line size, fuel rail, air cleaner, well you get the idea. Everything has to support you hp goal. A undersized fitting in the fuel line can choke you power. Runs great till 5300 rpm and then dies.
The wrong air cleaner can cost you 97 hp at top rpms.

I use a stock Ford distributor and ECU. NO MSD.

I would suggest you research the parts you need for the hp you want. The more hp, the more importance the parts become.
Have fun and enjoy the hp.

Dwight

[olddog]

Originally Posted by Seagull81

Everything is out of an '89 Mustang. It is mass air with a 70MM TB. My 302 has a '93 Cobra intake with 24 lb. injectors (MAF calibrated for 24s). I thought about using that intake on the 347. I assume I will also need a 155 fuel pump. I'm not in a big hurry as I am gathering parts. Do I need to upsize the fuel line or change the fuel regulator?

I'm just learning some of this, but I will share what little I think I know.

You have an EEC4 controller (ECU). It can be chipped to tell it what size injector and MAF meter. You can pretty much tune it any way you want. From what I read the 94/95 EEC4 was a different program and a bit harder to tune. Many Dyno tuners still work with this older technology. Some say it is better for performance apps. Younger guys never saw it, and do not work on it.

If you can afford it, hook up with a good dyno tuner. Otherwise you are going to invest a lot of time learning this, and you will spend as much money buying the tools as you would pay a tuner.

As Dwight explained, everything in the system has to be able to flow enough fuel to feed the maximum Hp.

Hope that helps.