Engine Swap Guide - Heavy Rotation
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.
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.
|4.6 Baseline||5.4 Baseline||Gains|
|5.4 Tuned||Total Gains|
Having the foresight to see...
Having the foresight to see that the Coyote swap (into OG 5.0 'Stangs) would be popular, BBK created a set of bolt-in, 1-3/4-inch tubes that fully cover the exhaust side of the exchange. The full-length headers (PN BBK16340; $757.98) feature 3-inch collectors that mate to an X-pipe that's available in two flavors; with catalytic converters (PN BBK-1786; $499.98) and as a straight-through deal (PN 1787; $237.98).
After years of dwindling participation...
After years of dwindling participation in its Real Street and Pure Street eliminators, the NMRA launched the all-new Strange Engineering Coyote Stock class in 2012. The class, presented by 5.0 Mustang & Super Fords, is designed for race-specific Coyote transplants in '54-and-newer Fords that weigh a minimum of 3,200 pounds, and are highlighted by Ford Racing Performance Parts' factory-sealed crate engines (PN M-6007-M50S; $7,099) and Copperhead processors.
Notice the steel cap that's...
Notice the steel cap that's stamped over a timing-cover bolt. Each Coyote Stock engine features four such seals (two on the timing-cover bolts and two on the intake-manifold bolts). With Ford's OE transmissions and Tremec's five- and six-speed gearboxes being the only manuals allowed (along with C4s for those who choose not to shift), this class is sure to bring affordable 10-second excitement to the NMRA.
Believe it or not, this 4.6-liter...
Believe it or not, this 4.6-liter Three-Valve engine is sitting in the engine bay of a '98 Mustang GT. That's right. Keith and Duane Logan of Logan Motorsports have completed development of a one-stop package that makes replacing a '96-'04 Two-Valve engine with an '05-'10 Three-Valve 4.6, a simple swap. We really like this new swap for '96-'98 GTs that haven't been treated to a PI upgrade, as unmodified Three-Valves typically can add more than 100 hp to the feet of those under-powered 'Stangs.
The complete system includes...
The complete system includes everything shown (throttle body, throttle cable and exhaust adapter plates are among key pieces), most important is its pigtail harness, which plugs directly into a modular-powered SN-95/New Edge PCM and wiring, for no-hassle engine management (no worries about having to lock out the Three-Valve's variable camshaft timing or figuring out adapting drive-by-wire). Logan's Two- to Three-Valve conversion package lists for only $1,499 (or $1,899 with an SCT XCal3 programmer that's pre-loaded with Logan's custom ECU programming).
As Ford Racing Performance...
As Ford Racing Performance Parts focused primarily on Four-Valve modular engines, Three-Valve powerplants for this swap must be sourced via Mustang shops, wrecking yards, and Mustang-parts classifieds online. This low-mile Three-Valve is slated for a swap project being performed by our friends at GTR High Performance. Stay tuned to future issue for all of the details on how it’s done and the difference it makes in an SN-95 GT.
Due to the oil pickup actually...
Due to the oil pickup actually falling a half-inch deeper in a Two-Valve 4.6 pan, the oil pan from the smaller engine is used on the 5.4 block. However, while the fitment is fine, the 5.4's longer stroke (4.16 vs 3.55 inches for the 4.6) creates a conflict between one of the rod bolts and the oil-control baffles in the 4.6 pan. Bending the baffles down a quarter-inch solves the problem.
When using a donor engine...
When using a donor engine from an Econoline van, note that since these vehicles require a relocated oil filter, the 5.4 filter mount will not work in a '99-'04 Mustang. A 'Stang's oil-filter mount and lower-radiator-hose connection are required, and can be used with the 4.6 engine's factory gaskets, as the newer-design, O-ring-style gaskets do not crush.
Dropping a 5.4-liter engine...
Dropping a 5.4-liter engine from a Ford truck/van has long-been equated with replacing a Fox's pushrod 5.0 with a 351W powerplant. Like the 351W, a Two-Valve 5.4-liter modular provides immediate, increased torque to Ponies of Two-Valve 4.6 heritage. One of the nuances in this swap is that a 5.4's taller deck height and the need for intake-adapter plates that are 1 to nearly 2 inches thick, which can actually raise the throttle body almost 2-1/2 inches higher. Removing a section of the stock hood's bracing or adding a taller, aftermarket hood, creates the necessary clearance.
The 5.4's dipstick tube must...
The 5.4's dipstick tube must be reshaped just a bit, and a new hole is drilled in the bracket so that it bolts in the same location as it on a 'Stang's 4.6.
Although it's much narrower...
Although it's much narrower than a Two-Valve 5.4 intake manifold, the stock Two-Valve 4.6 intake manifold can be used on the 5.4-liter bullet. Custom adapters (that align ports and water passages to the 5.4 heads) are necessary for this; 1-inch plates are available through Reichard Racing (www.reichardracing.com; $375). Stock 5.4 intakes are not preferred for this application, largely due to their height and positioning of the throttle body and sensors.
Since modular engines are...
Since modular engines are not balanced with a flexplate when the engines are assembled, the 4.6 and 5.4 plates can be swapped without requiring any funky fab work—as long as the 4.6 plate was hung on an engine that has an eight-bolt crankshaft (built in Ford's Windsor plant). For swaps being done with automatic transmissions, the 4.6 flexplate is required, as it has a slightly smaller-diameter bolt pattern for the torque converter.