Engine swaps are the quintessential...
Engine swaps are the quintessential hot-rod modification because there’s little in life more fun than a big engine in a small car. A happy swap, such as this classic 351W in a Fox, combine a combination of reasonable weight, available supporting parts, and workable packaging, along with the main attraction of increased power. Those able to handle the more complex modular engine transplants enjoy increased smoothness and fuel economy compared to the typical pushrod starting point.
When the cherry picker meets the metal, the point of most engine swaps is to get the most powerful engine into the smallest car. It’s the way cars should be built in the first place, we figure, but sometimes the factory needs a helping hand and you end up doing the job yourself. Let’s face it--it ultimately would be easier to buy a car with the engine you want already there, but a car with a swapped engine is always going to garner more attention and carry more street cred that an off-the-lot install.
Now, if there ever was a poster boy for the phrase the devil is in the details, the engine swap is it. In the zeal for more power, it’s easy to over look some of the physical realities of a monster engine or the numerous logistical headaches they pose. To put it bluntly, compared to the modern steady diet of bolt-ons, an engine swap can generate headaches because there are plenty of decisions to make and often parts to build. To help, we’re presenting this overview of common Ford engine swaps. We want you to gain a feel for what the finished swap is like and it’s relative difficulty.
Let’s observe that besides being great fun, engine swaps are generally a hassle. The car is typically an immoveable lump in the garage for weeks, and you spend the majority of the time chasing little stuff such as brackets and wiring diagrams. Get adventurous with a truly exotic swap, and you could find yourself getting schooled in why exhaust headers cost so much when you have to design and build your own, or learning far more about electronics than you dreamed possible thanks to a modern computer that wants to know what the brake lights and electric power steering are doing before it will turn on the engine.
Dave Smith’s Terminator-powered...
Dave Smith’s Terminator-powered ’94 Cobra exemplifies the difficult but rewarding blown Four-Valve swap. Dave transplanted a wrecked ’04 Cobra’s entire driveline, wiring harness (complete car harness), AC system, braking system (including hard lines), fuel system including the tank and filler neck, dashboard, airbags, radiator, steering rack, an so on, into his ’94. The job required eight months.
Because of this hassle factor, we strongly suggest--
demand would be a better word--that firsttime swappers or those without a reasonably complete home shop and fabrication skills stick with common engine swaps that are well supported by aftermarket parts. And for the same reasons, engine swaps are best reserved for hobby cars, not daily transportation.
A major consideration is electronics because the cars in question span the carburetion-to-electronic fuel injection divide, and EFI has been evolving ever since. There are endless variations in wiring harnesses and their connectors in the last 25 years of Mustang production to accommodate model years, variations in automatic versus manual transmissions, and 49-state versus California or 50-state cars, among other things. There are also return and returnless fuel systems, distributor, distributorless and coil-on-plug ignitions, plus mechanical and electronic throttle bodies, anti-theft keys, electric power steering, variable cam timing, and more. In general, the pros tell us the ’05 Mustang ushered in a new level of electronic complexity and the ’11 Mustang seems to have made an equally large jump.
Luckily the aftermarket has been working hard on adapting these various systems. We don’t have space to list them all here, but the most important are the recently introduced Control Packs from Ford Racing. These are a godsend to Three-Valve 4.6 and Four-Valve 5.4 swaps, as well as their intended purpose of supporting FRPP crate engines in kit car and street-rod swaps. And don’t overlook carburetion for simple track or strip cars. It can save you many headaches, and you can always return to EFI later if desired.
Much of what we call engine swaps today are actually crate-engine installs. Traditionally an engine swap is best supported by buying as much of the donor car as possible to gain cost-effective access to supporting pieces such are wiring looms, brackets and such. That’s not possible with a crate engine install, so think through where all the parts are coming from before writing any big checks. Remember, the big parts are easy, it’s the little stuff that’ll devil you.
All that said, an engine swap can be the easy, inexpensive, and durable path to big-displacement fun, or it could also be the right choice for modernizing an older chassis with newfound smoothness and speed. And don’t forget, you can always supercharge a big engine too!
Horse Sense: The June ’02 issue of 5.0 Mustang & Super Fords has several engine swap articles detailing some of the swaps we discuss in this story. For converting a 3.8 SN-95 to 5.0 power, see the Feb. ’09 issue. If you can’t find the printed magazines, the stories are available online at www.50mustangandsuperfords.com.
Looking like it grew there,...
Looking like it grew there, Dave’s Terminator swap gives his ’94 Cobra some ’03 Cobra power. It’s a unique conversation piece and was a fun project.
Looking for an engine swap...
Looking for an engine swap that features modern power but is also realistically possible? The Three-Valve from the ’05-’10 Mustang GT is the answer. Seen here in it’s native S197 engine compartment, the Three-Valve is affordable, available, reasonably compact, supported by an FRPP Control Pack, and when boosted with a blower as shown here, can give mid-500hp performance with pump gas. If you want smooth, fun-driving modular power, this is the easy, worthwhile swap.
Jay Willey’s Fox coupe does...
Jay Willey’s Fox coupe does a good job representing a realistic 351W swap. Built from a Lightning block, the Windsor measures 408 cubes and aspirates via a Barry Grant carburetor to the tune of 536 hp and 520 lb-ft of torque. That put the street/trip hobby car through the lights at 10.45/131 mph, so it runs as well as it looks.