Engine Swap Guide - Heavy Rotation

As the cover announces, engine swaps are the theme of this month's issue. And, as veteran readers know, swaps are a popular topic we've covered with stories ranging from providing details on replacing four-cylinder and V-6 engines in Fox Mustangs with 302s, 351Ws and even big-block 460s. The same type of focus also has been given to modular-engine exchanges, as rotating those bullets among the various Pony platforms is just as popular. While there are tons of viable swaps that can be pulled off, we're looking at some of today's popular trade concepts in this report; of which many are centered on Ford's modular engines.

Leading off our rundown is the latest craze; transplanting a Coyote 5.0 engine. This swap by far is the hottest of its kind right now. As a matter of fact, installing the new '11-'13 5.0 in other 'Stangs and Fords is so hot, the NMRA has even added a Coyote-only eliminator to its heads-up drag-race lineup for 2012. This speaks volumes to the general optimism about the modular 5.0's future.

Of course, the tried-and-true pushrod swaps (four-cylinder-to-5.0, 5.0-to-351W or 460) will never be forgotten, as they were ground-breaking advancements in Mustang technology years ago; a swatch of the proverbial fabric from which modifying late-model 'Stangs was made. We've covered details on those engine transfers and others ("Pop Swaps ," Nov. '06; "Trade Secrets," Nov. '07), and suggest you consult our website for refresher info. Again, a majority of the engine exchanges being performed today involve modular powerplants, and the supporting equipment and thought that's required for completing the task.

As you'll see while reading through the following photos and captions, highlights in this report are focused primarily on the hot mod-motor swaps. Limited space in the magazine unfortunately prevents us from providing every granule of information on every swap. However the overviews presented here definitely will give you a good awareness of how cool and do-able a radical engine swap can be.

Horse Sense: There's no denying today's underhood action is the most exciting since Ford hit us in the head with supercharged Condor 5.4-liter engines, which power '07-'12 Shelby GT500s. By all rights, V-8s definitely are the cornerstones of late-model, fuel-injected Mustangs. And as such, we really dig it when we see 'Stangbangers put 4.6-, 5.0-, 5.4-, and 5.8-liter powerplants, in Mustangs that Ford never intended.

5.0 Coyote Fox/SN-95

Installing a Coyote 5.0-Liter, DOHC engine in any late-model Mustang is, without question, the hottest engine swap in our hobby right now. As we anticipated it would, the Fox-body/SN-95 transplant became an instant favorite, which was made possible by Ford Racing Performance Parts offering Coyote engines and all their necessary wiring as affordable, turnkey/plug-and-play packages. The coming together of Coyotes and lightweight '79-'95 Mustangs creates instant driving fun, based on a power-to-weight ratio that teeters on ridiculous (before hop-up mods on the new 5.0 even occur), and the overall coolness of seeing a modern-day 5.0 engine in a Pony that once had swagger with a pushrod versions of the 5.0.

Initial efforts at mating old with new, pioneered by Mustang shops such as Kurgan Motorsports in Georgia, Christian France of High Flow Fuel in Southern California, and LaMotta Performance (owner Jake LaMotta spearheaded the Coyote swap in Associate Editor Mike Johnson's '94 Cobra) in Florida, were fraught with nuances that are part of exploring new territory in late-model Mustang technology. Such pieces as K-members and power-steering brackets, as well as interfacing with the factory wiring system, all needed sciencing out. One thing we learned the crate engine does not include, is an engine plate (block protector), so remember to purchase one through your Ford dealer before going to install the engine.

Thankfully, those issues are cleared up and there are several aftermarket companies that now produce almost all of the hard parts necessary for installing Coyote 5.0 engines in '79-'95 Mustangs. And, with the engines being as power-adder compliant as they are, this latest segment of engine swaps creates a huge potential for enthusiasts to build wicked street Ponies, with 5.0-liter power that goes far beyond the 215-235 horses of the pushrod originals.

SN-95/New Edge Three-Valve

It's hard to believe the process of swapping a 4.6-liter Three-Valve engine into an SN-95 Mustang is actually 6 years old. That's right. Logan Motorsports performed this exchange back in 2006 (with a kit that required locking out the engine's variably timed camshafts), and since that time the company has been working on a package that makes the effort a lot simpler.

As at-large-editor Tom Wilson noted in a prior essay on engine swaps, "The Three-Valve is an excellent performer and readily available." This broad availability--these days through wrecking yards/auto dismantlers, Mustang shops and the Internet--and the engine's inexpensive price definitely make it a cost-effective mod-motor for installing in non-S197 Mustangs.

Thanks to prevalent aftermarket support for Three-Valves, this swap has come of age. And with the reduced weight, improved gas mileage, and performance increase it brings (for less than the price of the average supercharger system), we see this swap as a no-brainer for anyone looking to upgrade the tired Two-Valve engine in a '96-'04 Mustang GT.

New Edge SOHC 5.4

If you're looking for comparisons in the pushrod/modular engine-swap universes, the best way to look at the '99-'04 4.6 to 5.4 Two-Valve upgrade is as a modern-day 5.0-to-351W swap. While engine-in/engine-out is the physical comparison, the instant (and significant) torque increase is the shared result of each transplant.

Because the two PI Two-Valve modulars are generally built from the same stock (they even share similar engine internals such as crank, pistons, heads and cams), their accessories such as oil pan, and water pump are interchangeable, right down to their mounting locations. The big exceptions are the intake manifold and a '99-'04 Mustang's exhaust, which requires significant H-pipe modification for proper fitment.

This archived dyno chart presents a look at the gains, especially torque increase, that typically come from swapping a stock, Two-Valve 4.6-liter with an equally OEM 5.4-liter engine. It's important to note that for this test, despite the similar configuration of both engines, peak power comes at a lower rpm with the modified (with adapters) intake on the 5.4, as compared to the peak-power range of the 4.6.

Clevor Fox

We recently took the 351-swap concept a step further; building a 351W-based, fuel-injected, Cleveland-headed, 408 stroker, and installing it in Greg Montoya's '89 Mustang GT.

All of the articles detailing Greg's "Project Leave It to Clevor" can be found on our website.

The Originals

Here's a breakdown of some of the pioneering engine swaps for late-model Mustangs, compiled by editor-at-large Tom Wilson. It's hard to process the fact that it really wasn't all that long ago, when these four engine swaps were at the top of the charts.

Pushrod 5.0

This is one of the easiest swaps because readily available, stock factory parts are all you need to replicate a 5.0 LX or GT from a humble 2.3. Furthermore, if you're interested in what the swap will turn out like, just drive a 5.0 Fox. In fact, because there are so many V-8 Foxes still available, our first advice is to consider selling your 2.3-liter project Fox and buy an H.O. as your starting point. It's often the quicker, less expensive, and easier option.

On the other hand, converting a four-banger can be a smart move. By now old Fox Mustangs need everything, so ditching a pile of wasted, puny four-cylinder driveline parts is a no-brainer if you're installing a 31-spline rear axle, T-56 trans, a new suspension, and big disc brakes anyway. That makes this swap especially appealing for race cars and Saturday night shakers--cars that care little about interior niceties and depend more on an unwrecked, rust-free unibody than anything else.

Conversely, if you're going for a clean street car, you're almost always better off starting with the cleanest street 5.0 H.O. you can afford and selling that four-banger your uncle gave you. This is especially true if considering an early Fox with a brittle SROD transmission or 7.5-inch rear axle.

Technically, the V-8 into a four-cylinder Fox swap can be accomplished with little more than a V-8 engine, engine wiring harness and computer, but as the horsepower goes up, so does the need for more robust supporting pieces, such as larger radiators, better clutches, bigger fuel pumps, and so on, so don't overlook those upgrades in your planning.

Pushrod 5.8

When Ford developed the 351 Windsor, it invented the best reason to swap engines-displacement in a compact, affordable package. We're not going to get too deep into the 351 swap from a nuts and bolt standpoint because it's a well-known job and reasonably straight forward. That, and there seems to be as many ways of making a 351 work as there are 351 swaps because the aftermarket is positively dripping with parts.

That said, the only Mustang since the '70s to get the 351 was the rare '95 Cobra R (only 250 were built). That gave us all the parts when dropping one into an SN-95, but you'll need more help in a Fox or New Edge. Start by reading "351 Engine Swap" from our May '01 issue. It's also on our website and gives the necessary details. We also highly recommend Maximum Motorsports (www.maximummotorsports.com) K-member for this swap to offset the heavier engine's weight and open up header room. The gain in handling is important, too.

What we'd like to concentrate on is why the big Windsor is such a good swap. Most importantly, exceeded only by the behemoth 460, the 351 offers far more cubic inches of displacement than the pencil-neck modulars or the tightly packaged 302. Even better, the 351 can be built to well-over 400 cubes with passable durability, and those engines pack an immediate low- and midrange torque hit that's a blast to drive.

Windsors are durable, too. Even the stock blocks are notably stouter than 302 blocks, and the heavy-duty FRPP Sportsman and aftermarket blocks are anvil tough. But they aren't big! A 351 poked and stroked to 427 inches is much more compact than a 281ci modular; this makes them far easier to install and work on. These engines aren't overly expensive in near-stock trim, either, although a full-house stroker will add up for sure.

The downside to the 351 is that it's a full notch heavier than the 302, and the legacy Two-Valve pushrod design does not match the newer modular in smoothness, fuel economy, or breathing without good aftermarket cylinder heads. But for quickie street-oriented performance, the easy low-end torque is sure to please; if major power is wanted, there are race heads and big displacement on your side.

Two-Valve 4.6

Like putting a pushrod 5.0 in a four-cylinder Fox, slipping a Two-Valve 4.6 into an SN-95 is simply duplicating what the factory has already built in the Mustang GT. Once again we say you should take a hard look at simply buying a V-8 Mustang as the starting point and selling whatever V-6 car you may already have. That's not always the best move depending on what you're aiming for in the finished project, but it's definitely something to consider.

An advantage to the SN-95 is there are fewer differences between the V-6 and V-8 versions. This is especially true with the '99 and later New Edge cars, which all came with a 3.27-geared 8.8-inch rear axle. The '99 and later GTs all sport coil-on-plug ignition, too. That's one less wiring hassle when wiring in a later modular V-8.

One significant difference is the '94 and '95 GTs, which used 5.0 pushrod engines and classic EEC-IV engine management, while the same year V-6 cars had already moved on to OBD-II electronics with a data port. When the 4.6 Two-Valve went into the GTs in '96, they too were OBD-II cars. Another detail is all manual-transmission, modular-powered SN-95 GTs use a T-45 gearbox as opposed to the T-5 in the previous Fox cars. The meaningful difference is the T-45 has an input shaft that's 5?8-inch longer than T-5. It was needed because Ford actually moved the engine slightly forward in the SN-95s.

Terminator 4.6

At some point an engine swap goes from an interesting challenge to impossible for the home mechanic, and that line lies between the naturally aspirated Three-Valve 4.6 and Terminator Four-Valve swaps.

There are two reasons the exciting supercharged '03-'04 Cobra engines are beyond the capabilities of a home garage enthusiast--the engine's physical size and the complexity of its electronic controls. Together these make swapping the Terminator into an earlier Mustang daunting. While it can be done, it is often too expensive and too encompassing for the average guy.

But as noted, it can be done. On the physical size standpoint, you'll need Hydraboost (or manual brakes) to clear the cam covers, you'll want the Terminator's gas tank and fuels pumps, and you'll find plenty of fabrication work hanging the charge cooler radiator, relocating the radiator, making a rear transmission mount, an so on. Electronically the Terminator wiring runs to the instruments, the transmission, and as far away as the taillights, with GEM and fuel pump modules previous cars don't have.

In short, installing a Terminator in an earlier Mustang is pretty much installing an '03 Cobra's brains and mechanicals into the bodyshell of another car that wasn't particularly designed to accept it. It is definitely a pro job.

All of this adds up. A Terminator engine is about $8,000; the transmission, $4,000. It takes 60-100 hours of pro labor to put it all together, so that's another $8,000 or so, and that doesn't begin to include the upgraded suspension, brakes, blowers, fuel systems, sound systems, and other stuff such massive projects tend to attract.