Mustang Engine Swap

Engine swaps have always been a favorite trick of hot-rodders, but plugging in a 16-valve Cobra engine, Ford's 4.6-liter dual-overhead-cam modular engine, presents a whole new type of challenge. Complicating matters is that the Cobra 4.6 is taller and wider than most small-block V-8s. However, the issue really comes down to a small, computerized key.

Passive-Aggressive Plugging in a Cobra 4.6-liter engine presents a whole new type of challenge.



"A Cobra engine won't run outside of the original chassis that it was installed in," explains Mark Sanchez of Advanced Engineering West (AEW). "It has a Passive Anti-Theft System (PATS), a radio transmitter with a key code, and the car won't start without the chip in the steering column that has the same frequency as a box in the trunk. The code identifies the correct key." Overcoming that problem involved a few weeks of head-scratching by AEW to create a $400 module that plugs into the engine computer and bypasses the PATS. From there, the rest of the swap was easy by comparison.


Why go to all this trouble in the first place? "Better breathing," adds Sanchez. "Those Hemi-style 16-valve heads on the Cobra flow so well, they are ideal for massive amounts of boost from a supercharger." Although Sanchez does most of these swaps on '96-'98 Mustangs, he's also put the modern motors into '79-'02 Stangs as well as a variety of Thunderbirds and Lincolns.


For '79-and-later V-8 Mustangs, AEW charges about $3,000 for the conversion, which takes about a month. (Replacing the OE four-cylinder turbo requires a bit more time.) Since the mod motor is about 175 pounds lighter, AEW also recommends softer springs (such as the $225 Eibach coils). Also, the Cobra radiator ($250) should be used, but it first must be modified by cutting off its bottom ears and welding on custom upper brackets.