Evan J. Smith
Freelancer
May 7, 2015

Ford has always been a progressive company. Seeing the future, it abandoned the classic pushrod 302 in the Mustang for 1996 to make way for a new breed of Ford modular engines. Ford’s intent was to build a family of engines for passenger cars and trucks with improved emissions, less NVH (noise, vibration, and harshness), and better performance. These engines would also share common architecture, such as bore spacing, mounting, and overall block design. This gave Ford the ability to produce a variety of engine types in one plant by simply changing tooling. In fact, the “modular” moniker comes from the ability to quickly change tooling, not because many parts on the engines are interchangeable, as is often thought.

The modular Mustang engine craze began nearly 20 years ago with the introduction of the 1996 GT and the SVT Cobra. In that landmark year, Ford moved from pushrod power to overhead cams. Those 4.6L SOHC and DOHC powerplants laid the groundwork for the amazing technology and performance we enjoy today. Modular engines were built in Ford plants in Romeo, Michigan, and Windsor, Ontario, Canada.

Frankly, Ford recognized that a more efficient engine was needed to meet or exceed the federally mandated fuel economy requirements of the 1990s. Ford also saw the need to improve output, sealing (namely gaskets), and reliability. Improvements on the modular came from a deep-skirted six-bolt main block, lighter rotating assembly and by mounting the accessories directly to the engine instead of hanging them off a bunch of brackets. Modular engines include the 4.6L Two-Valve, Three-Valve, and Four-Valve, the larger 6.8L V-10, and even the 5.4 and 5.8 Cobra and Triton truck variants. According to Ford, the Coyote is not considered a “modular” engine.

A major advantage of the modular engine is the deep-skirted block. It features six bolts per main cap: two inside the block and two cross-bolts that are inserted from the side.

At 4.6L (281 ci), the first modular was smaller than the outgoing 302. With small displacement, it would have to rev to make power, but Ford also knew the engine would need suitable torque. With the Mustang growing in size, enthusiasts expected Ford to respond with a larger displacement powerplant.

Unfortunately, the first Two-Valve didn’t impress enthusiasts. While the engine had overhead cams, including aluminum heads with nicely shaped intake runners, the ultralong runner intake seriously limited power above 5,000 rpm. The big news was the DOHC SVT Cobra, which made nearly 100 more horsepower (305 hp). The Two-Valve version (215 hp) fell short of expectations, but Cobra owners loved the high-rpm four-cam wonder.

Two-Valve

There are three basic types of modular engines: Two-Valve, Three-Valve, and Four-Valve.

While the Two-Valve didn’t get the warmest reception, it did have excellent attributes. It featured a composite intake manifold (which stayed cooler than aluminum), aluminum heads, and distributorless ignition. While only making 215 hp, modifications came easy, and so did extra power. Rather than retreat, Ford marched on with the technology, and soon horsepower climbed.

It should be noted that the very first Two-Valve engines were used in the 1991 Lincoln Town Car. It produced 190 hp, but power was increased to 210 by 1994. The 1996 Mustang version made 215, which matched the outgoing 302. On-track performance was about the same as the 302, with the 1996 Mustang GT nudging into the 14s.

The most potent factory Two-Valve is the 2001 Bullitt, which produced 265 hp thanks to a unique cast-aluminum intake manifold.

If there was a downside for enthusiasts, it was the complexity that limited the aftermarket from generating major parts like intakes and heads quickly. Ford improved the Two-Valve dramatically in 1999 with its Performance Improved (PI) induction. This consisted of a redesigned intake and cylinder head with much better flow characteristics, resulting in 260 hp and 302 lb-ft of torque. Real-world performance was enhanced, as the Mustang now was a solid 13-second performer. Best of all, basic mods, such as performance-minded (3.73-4.10) rear gears, cold-air intake, underdrive pulleys, computer reflash, exhaust, and good driving, could produced 12-second times. And with nitrous and boost, performance was limitless.

While most parts are interchangeable, there are differences between engine build at the different plants. Romeo cam covers use 11 bolts; Windsor engines use 13 bolts. But wait, there’s more. Windsor blocks get marked with a “W” in the casting, and Windsor heads don't utilize cam journal girdles. On the blocks, Romeo versions use jackscrew cross-bolts on the caps, and Windsor blocks sport a dowel pin. It’s also commonly known that Romeo cranks use six-bolt flywheel/flexplate flanges and Windsor engines use eight. Due to the variety, it’s better to start your Two-Valve project with a complete engine, even if it doesn’t run.

Three-Valve

As you know, 2005 was a landmark year for Ford. The automaker introduced the S197 Mustang and, at the same time, gave us the 4.6L Three-Valve modular. Enthusiast not only got the retro-style Mustang they had been craving, but they also got 300 hp. This combination added excitement to the Mustang. Engineers extracted 40 hp from the same 4.6 liters of displacement with an additional intake valve, Charge Motion Control Valves, and variable camshaft timing. The Three-Valve engine not only looked way cooler than its predecessor but outperformed it in every way.

The foundation of the Three-Valve V-8 was a new aluminum block that saved about 90 pounds and was topped with unique SOHC aluminum heads and a high-flow composite intake manifold with a forward-facing throttle body. The CMCV plates enhanced airflow velocity and improved cylinder filling at low to mid rpm. Despite the heavier weight of the S197 chassis, the 2005 Mustang was capable of mid 13s at 105 mph.

Today the aftermarket is flooded with parts for these engines. S197 Mustangs offer a great value and clean GT examples can found for $9,000-$12,000. It’s worth noting that 2005-2010 Mustangs work great for drag racing, open track, or autocross. They respond well to basic mods, as well as superchargers and turbos.

4.6 DOHC Four-Valve

Ford’s SVT (Special Vehicle Team) designed and built a completely new engine for the 1996 Cobra. While it used the same bore and stroke as the iron-block Two-Valve (3.552 by 3.543 inches), the 1996 Cobra engine featured an aluminum block made by Teksid in Italy, dual-overhead cams, and a high-flow intake manifold. This DOHC V-8 was a screamer for the time, producing 305 hp and revving smoothly to 7,000 rpm.

Cobra engines were hand-assembled by trained technicians in Ford’s Romeo, Michigan, engine plant. Once completed, the technicians would then sign a small SVT plate that was affixed to the cam cover. SVT touted the new all-aluminum mod mill as the future of Ford V-8s—but it was only a taste of things to come. In addition to the Mustang, the 32-valve modular engine was also used in the 1993 Lincoln Mark VIII. It produced 280 hp and received a bump to 290 in 1995. The Lincoln Continental also used a variant of the 4.6 DOHC engine in FWD configuration.

From 1996 to 1998, the SVT Cobra received a 305hp DOHC engine that revved smoothly to 7,000 rpm. This one has the added benefit of a Vortech supercharger.

The aluminum block saved close to 100 pounds, which enhanced handling of the SVT Cobra. To take on the task of 7,000-rpm operation, Ford used a German-made forged steel crank, powdered-metal forged connecting rods, and forged pistons. Feeding air was the impressive four-valve heads, which featured split intake ports. The early heads are termed “B” heads. The split ports with CMCV plates allowed for greater velocity and improved airflow. Furthermore, the ports were straight, which is optimum for performance. All 1996-1998 Cobra heads feature 37mm intake and 30mm exhaust valves with the spark plug located in the middle of the combustion chamber.

Of course, enthusiasts are familiar with the nicely shaped aluminum intake that featured a large central plenum with long individual runners. The Cobra engine also utilizes the aforementioned butterfly in one intake port that opens at 3,250 rpm. Limiting airflow to one port improves velocity at low engine speed and enhances efficiency and power. The DOHC Cobra engine also used the twin 57mm throttle-body, 80mm mass air sensor log-style exhaust manifolds.

Looking for more power, SVT modified the engine for 1999. SVT used improved “C” cylinder heads with a “tumble-port” design in the combustion chamber, and while the engine still breathed through a twin-bore 57mm TB, the intake was completely new. Ford also eliminated the butterfly plates. The 1999 SVT Cobra engine also featured coil-on-plug ignition and a more durable bottom end. Unfortunately, many 1999 Cobras failed to meet the advertised power output. Ford made good by redesigning the intake manifold, providing a reflashed computer and upgraded exhaust. Because of the debacle, no 2000 Cobras were built (save for the 2000 Cobra R, of which 250 were built). The SVT Cobra returned in 2001 with little-to-no changes.

Ford enhanced the power for 1999 on the SVT Cobra by modifying the cylinder heads and intake manifold. Pre-1999 heads are referred to as “B” heads, and the post 1999 tumble-port heads are called “C” heads. Heads are interchangeable on V-8 modular blocks so long as you use the intake type that originally came with the heads. The later heads are better flowing and more desirable.

Other 2013 Shelby GT500 Engine Features
Bore x Stroke 3.68 x 4.165 in.
Bore Spacing 3.937 in.
Deck Height 10.067 in.
Oil Pan Cast, 8.5 qt. capacity
Windage Tray integrated with the oil pan gasket
Pistons Mahle forged with friction coating
Connecting Rods Forged steel, I-beam
Crankshaft Forged steel with tungsten mass balance
Heads Aluminum DOHC
Compression Ratio 9.0:1
Camshafts Ford GT spec
Throttle Body Twin 60 mm
Mass Air 105 mm
Firing Order 1-3-7-2-6-5-4-8
Ignition CVoil-on-plug
Injectors 54.8 lb/hr

R Is for Race

The first really hot naturally aspirated four-cammer mill was found in the 2000 SVT Cobra R. It made 385 hp and sounded amazing.

The mighty 2000 SVT Cobra R completed the trifecta of R-model SVT Mustangs. SVT evolved the 2000 model and delivered a true racer for the street. The heart of the beast was a 5.4L DOHC monster producing 385 hp and 385 lb-ft of torque.

While many thought the larger 5.4L wouldn’t fit in the SN-95 chassis, Tom Bochenek, the Cobra R project manager, and his team were determined to make it work. They lowered the engine 6 mm, moved a few lines and hoses, and of course added the popular power-bulge hood to clear the massive intake manifold.

Ford also produced a variety of modular racing engines for road racing and NHRA. This is the 5.0 “Cammer” used in Grand Am Cup road racing.
This is an iron block 324-cube DOHC built by Livernois Engineering for our Project Superfly DOHC. It produced well over 500 hp on pump gas.

To extract maximum power, the team developed a new cylinder head with airflow 25 percent better than the standard Cobra DOHC heads. This was done with basic hot-rodding tricks, such as improving the port design, installing 2mm larger valves, and improving the combustion chamber. In addition, the team went with 0.520-inch lift cams (0.120-inch larger than the standard Cobra) and the exhaust flowed through Bassani short-tube headers. If driven properly, the 2000 Cobra R is capable of 12.40s at 112 mph.

Back to Blowers

With only 281 ci, forced induction was the way to go if you wanted big power (or easy power) from your modular. The aftermarket is flooded with blower and turbo kits, and of course nitrous is not a bad option either.
Of course, you can buy a complete crate or pullout engine to swap into your Fox or other Mustang or fast Ford. We spotted this GT500 engine at an NMRA event.

Ford fans had to wait until 2003 for the next SVT Cobra. The rumor mill was swirling about an intercooled and supercharged Mustang, and that’s exactly what Ford delivered. Dubbed Terminator, the 2003 SVT Cobra was indeed ready to terminate the competition.

Under the guidance of O. John Coletti, SVT designed what was the most lethal regular-production Mustang to date. Coletti tore a handful of pages straight from the “how to build a race engine” manual. He switched to a super-sturdy iron block and stuffed it with a forged steel crank, Manley H-beam connecting rods with ARP rod bolts, and forged pistons. The pistons were dished to lower compression and featured an offset wristpin, and a ring pack suited to handle the higher cylinder pressure of the boosted engine. Output was rated at 390 hp and 390 lb-ft of torque, but the engine produced closer to 425 hp at the crank. In stock trim, MM&FF tested a preproduction 2003 Cobra and ran an amazing 12.43 at 112 mph on the stock tires.

Ford got serious in 2003 by adding an Eaton M112 supercharger to the DOHC engine. Not only did this engine have extreme output but it was rock-solid with forged race internals.

Aside from free-breathing four-valve heads, the 2003-2004 Cobras benefited from an Eaton M112 supercharger with an integrated intercooler. Not only did Ford provide a race-inspired bottom-end but it included a blower with room to grow. Increasing the boost with a revised pulley setup drastically improved horsepower and torque on these engines. And today there are many bolt-on blower kits to bring output into the 600-plus range.

Shelby GT500

The pinnacle of horsepower came in 2013 with the 662hp Shelby GT500. The 5.8L beast not only had amazing horsepower but torque to spare!

Riding on the success of the Terminator, Ford fans expected the next “Cobra” to be boosted, but what they didn’t expect was the Shelby name and 500 hp. With the new S197 chassis, Ford impressed everyone with a fire-breathing 5.4L supercharged V-8—all stuffed in a “new” Shelby GT500. Taking what it learned from the 2000 R, and the 2003-2004 Cobra, SVT developed a supercharged 5.4L that had Earth-moving torque and reliable power past 6,000 rpm.

Enthusiasts loved the base package but also that Ford left room for upgrades. Enthusiasts wasted little time enhancing the engine with aftermarket cams, blowers, better-breathing inlet systems, and a free-flowing exhaust. The result was almost unbelievable. Bolt-on Shelby GT500s could eclipse 700-800 hp. Many enthusiasts pushed them to 1,000 hp!

This is the awesome Shelby GT500 Super Snake engine. When MM&FF tested the Super Snake it made 774 rwhp and ran 10.70s at 138 mph thanks to the massive Kenne Bell blower!

For 2010, the GT500 got a facelift and 40 hp thanks to mods that were on the 2008-2009 Shelby GT500KR. This included an Eaton 2300 supercharger and a revised calibration.

The big news for 2011 was not so much the extra 10 hp but rather the new aluminum 5.4L engine block, which saved over 100 pounds from the Shelby’s heavy snout. Ford also switched from iron cylinder liners to a Plasma Transferred Wire Arc liner. In this process, each cylinder gets a 150-micron composite coating for friction reduction. And with the addition of electric power steering, the Shelby GT500 saw an increase in power and fuel economy. The 2012 Shelby GT500 powerplant remained unchanged.

This is the 5.4L aluminum block that was used in the Ford GT. It was designed for dry sump, but some were converted to a wet sump and used in Mustangs. It offered light weight and great strength.

With each bump in power, enthusiasts kept wondering, Is this the end of the line? Seriously, 550 hp and 520 lb-ft of torque from a factory engine is downright awesome. But Ford saved the best for last. In 2013 it released a 662hp 5.8L GT500 that rotated the Earth with 631 lb-ft of torque. The fact that output jumped over 100 hp in a year speaks volumes about Ford’s ability to press the technology and deliver affordable performance. Amazingly, the 2013 Shelby GT500 eclipsed 200 mph in testing and ran deep into the 11s—and all without encountering a gas-guzzler tax.

Dubbed Trinity, the 5.8L is one special modular engine. To achieve over 650 hp, displacement was increased with a larger bore that uses a unique spray-bore on the cylinder walls.

SVT put forth a plan to reach 650 hp and 600 lb-ft of torque without tripping the gas-guzzler tax. Using the 5.4L as a foundation, SVT maintained the modular (100mm) bore spacing, deck height, cylinder heads, and remaining modular architecture. Stroking the engine was not possible due to the constraints of the block so bore size was increased from 330 cubes to 351. The block is cast by Honsel in Germany with a spiral groove cast into the cylinders. A rotating wire-feed using an electric arc and compressed air shoots the iron plasma onto the walls of each cylinder. The last procedure is to diamond-hone the walls into the proper crosshatch pattern. This results in a 93.5mm bore (the 5.4L is 90.2) and the extra cubic inches.

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Here’s an exotic Four-Cammer we found at a Performance Racing Industry show.

RPM equals horsepower, so SVT made necessary changes to allow the engine to rev to 7,000 for short bursts. Piston oil squirters and improvements to the cooling system help to drop operating temperature and ensure durability. Mahle was the piston supplier, and those slugs feature added strength over the past Shelby pistons. The connecting rods were also changed to fit (as the new pistons presented a clearance problem), but the rest of the rotating assembly was left alone (save for crankshaft balancing).

The short-block was topped with cylinder heads featuring enhanced cams with larger lift (1.1 mm and 1.4 for intake and exhaust, respectively). Ford also increased the strength of the exhaust valves with a tougher steel alloy material—the valve seats were also upgraded.

Perhaps the biggest kick in the pants came from a new 2300 (2.3L) TVS intercooled supercharger. The Twin Vortices unit is more efficient and also produced more boost. The outgoing Shelby made roughly 9 psi; the 2013 GT500 made 15 psi or more in some cases. The case design was enhanced and a large SVT 5.8L was embossed. This blower uses a four-lobe design, with 160 degrees of twist (the M122 uses three rotors and is twisted 60 degrees). Pulley size is a small 2.71 inches (69 mm).

That wraps up the timeline for the Ford modular engine. Look for Part 3 soon, where we’ll cover the Coyote 5.0, Road Runner and VooDoo engines.

Mustang Modular Power
Engine HP @ rpm Torque (lb-ft @ rpm)
1996-1997 4.6L Two-Valve 215 @ 4,400 285 @ 3,400
1997 4.6L Two-Valve 225 @ 4,400 290 @ 3,400
1996-1998 4.6L DOHC 305 @ 5,800 300 @ 4,800
1999-2004 4.6L Two-Valve 260 @ 5,250 302 @ 4,000
1999-2002 4.6L DOHC Cobra 320 @ 6,000 317 @ 4,750
2000 5.4L Cobra R 385 @ 5,700 385 @ 4,500
2001-02 4.6L Bullitt 265 @ 5,000 305 @ 4,000
2003-04 4.6L DOHC Cobra 390 @ 6,000 390 @ 3,500
2003-04 4.6L DOHC Mach 305 @ 5,800 320 @ 4,200
2005-09 4.6L Three-Valve 300 @ 5,750 320 @ 4,500
2007-09 4.6L Shelby GT 325 @ 5,750 330 @ 4,500
2008-09 4.6L Bullitt 315 @ 6,000 325 @ 4,250
2010 5.4L GT500 540 @ 6,200 510 @ 4,500
2011-12 5.4L GT500 550 @ 6,200 510 @ 4,250
2013-14 5.8L GT500 662 @ 6,250 631 @ 4,000

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