From 3.8Wiki
[edit] Introduction
A split port swap is when you replace the single port intakes and heads from a 1994-1998 3.8 with the split port heads and intakes of the 1999-2004 models, the split port top end is good for at approximately 40 more horsepower and is a popular modification for 1994-1998 owners. Most of the parts are interchangeable, and doesn't require an excessive amount of modification, but the variety of parts from year to year and variety of options when approaching each issue makes the process a bit more difficult to pin down exactly.
[edit] What's Involved
The components involved in the split port swap are the:
- Heads
- Upper Intake
- Lower Intake
- Fuel Rails and Lines
- Air Intake Tubing
- Exhaust System (Including EGR)
- Throttle Cable
- Accessories
- Wiring Harness
- ECU (Re-tuning it)
[edit] Obstacles
The Obstacles you'll be facing when performing a split port swap are:
- The 1994-1998 engines used a return style fuel rail, with a feed line and a return line back to the tank with a vacuum controlled fuel pressure regulator. The split port motors used a returnless fuel system with only a feed line and a computer controlled fuel pressure regulator.
- The single port fuel rail won't fit into split port heads since the split port heads have evenly spaced injector holes while the single port uses uneven spacing. The split port fuel rail lacks a return line, and so it can't be used without modification.
- The split port throttle is in a different position, so the stock 1994-1998 intake tubing won't fit.
- The split port lower intake only has one temperature sensor, which goes to the ECU, whereas the single port lower has two, one for the ECU and another for the instrument cluster.
- The 1994-1998 throttle cable isn't compatible with the 1999-2004 throttle body.
- Split port motors need larger fuel injectors, which can't be used properly without retuning the ECU
- 2001-2004 motors used IMRC's (Intake Manifold Runner Controls), which are essentially butterfly valves that open and close the second set of intake runners in the lower intake. Anything pre-2001 doesn't have any engine controls for these valves, so they have to either be wired open or removed completely.
- A few of the miscellaneous connectors in the split ports don't fit the single port wiring harnesses, and need the connectors to be spliced over. Namely the IAC (Idle Air Control Valve)
[edit] Parts List
There are a lot of parts involved in a split port swap, here is a general listing of what's needed to make it all happen
- Heads
- 99-04 Mustang Heads
- 97-? 4.2L F150 Heads
- Upper Intake
- 99-04 Mustang Intake
- 97-?4.2L F150 Intake
- 9?-? Windstar Intake
- Lower Intake
- 99-04 Mustang Intake
- 97-?4.2L F150 Intake
- 9?-? Windstar Intake
- Coolant Lines
- 99-04 throttle cable
- At least 21lbs/hr fuel injectors
[edit] How-To: Top End Swap
Stuff will go here
[edit] How-To: Complete Engine
Stuff will go here
The rest soon to come.
RoughRidin232 21:49, February 21, 2008 (CST)
