ID
The type of valvecover on a modular engine provides a quick identification. In this brief sidebar, the various styles of valvecovers are shown and described to provide a quick and easy indication of the particular engine. To verify the year, factory of origin, and type of modular engine, refer to the engine ID tag.
The 4.6 Romeo two-valve valvecover is a composite cover and has 11 bolts holding it to the head. Like all modular valvecovers it cannot be swapped left to right due to the timing chain and gear bulge in the front of the cover.
This typical early four-cam valvecover is painted black on this Shelby 5.4 engine. The silver center plate covers the four coil packs mounted over each cylinder. Earlier coil pack engines had a similar cover over the spark plugs and wires. The coil pack wiring exits the back of the cover.
The 4.6 Windsor-built 2V engines have a 14-bolt valvecover that cannot be interchanged with Romeo 2V valvecovers. (Photo Courtesy Jim Smart)
The 4.6 and 5.4 3V engines featured scalloped valvecovers to help with the relocation of the coils. The VCT (variable cam timing) system mounts in the front of the cover. These covers came in 10-bolt and 14-bolt designs.
The Coyote 4V engines have a much shallower valvecover and the wiring exits up and over the top of the cover to be hidden by the intake cover. The dual TC-VCT plugs can be seen in the front of the cover. The coil cover is aluminum and interchangeable.
Most crankshafts are cast nodular iron and have six or eight bolts to hold the flywheel/flexplate, depending on application and plant. Most performance aftermarket companies design parts for the stronger eight-bolt crankshaft design. When Ford came out with the 2003 Cobra, it opted for a forged steel crank to handle the supercharged engine. Forged steel cranks then started making their way into other production engines.
The intakes vary depending on application. Triton or Ford truck intakes tend to be taller with smaller, longer runners, whereas cars such as the Ford Mustang have the shortest intakes for clearance.
One of the early problems with the intake was a cracking condition with the new nylon designed intake manifold. The intake would crack along the front coolant crossover and the fitting ports would pull out.
Ford solved the problem with these 4.6 intakes by changing the design to include an aluminum crossover tube in 2002. This remained on the 4.6 production engines through the end. The design for later engines was improved and the intakes became all composite again.
Ford used multiple intake port designs on the modular engine, so swapping among different engines is very difficult. Ford had a factory recall late in the 1990s when a problem occurred with the all-nylon intake manifolds; the fix was an aluminum coolant crossover, which carried on through production in the early 2000s.
On the back of this GT engine, this servo arm device is called the Intake Manifold Runner Control Module and sometimes it is referred to as the Charge Motion Control Valve. It shuts off part of the intake runners at low RPM on some engines to help with low-end torque. Performance builders have developed eliminator kits to remove this part for performance builds, as it can rob power in high-performance engines.
With the early engines, Ford found that by adding a dual intake runner design and by shutting off runners at low RPM and idle, it could eliminate some of the low-end torque issues with the intake. Starting with some of the mid- to late-1990s Lincolns, Ford began using a dual port intake system, and this evolved into the Charge Motion Control Valve (CMCV) and/or the Intake Manifold Runner Control (IMRC) systems, depending on which year and engine you have. They both do basically the same thing: At low RPM it closes one of the runners to allow for better low-end torque.
So, which engine is right for your project? It depends on the goals for the project vehicle. The 4.6 SOHC 2V is plentiful and has the smallest dimensions for fitting in the engine bay, but because it is not at the high-end horsepower range, not a lot of new engineering takes place to develop parts for the older platform. As engines such as the Coyote continue to grow in popularity, aftermarket parts will become more difficult to obtain for the 2V as the sources dry up. In fact, while I was writing this book parts that were available became unavailable as they were replaced with parts for the newer platforms.
The older engine combinations may be easier to work with on items such as computers and wiring. The Ford computer controls sold through Ford Performance Parts made a big change on the ease of installing the newer engines, but they are only for use in the later throttle-by-wire setups.
The most popular conversion so far seems to be the Coyote platform. Available since 2011, plenty of used engines are now available, and Ford Performance Parts sells some amazing crate engines. Ford-sponsored PCM computer controls also helps with this platform’s popularity. Surprisingly, the 2003–2004 Cobra Terminator conversion remains a popular conversion engine. Plenty of horsepower, a rugged cast-iron block, and no throttle-by-wire, it was the epitome of cable-throttle engines, and Terminator engines have retained their value because of this.
If the project budget is on the lower side, an SOHC or older DOHC can be used and performance added as needed. Engine platforms such as the Cobra DOHC, Raptor 6.2, Lightning trucks, and Shelbys provide a good foundation with proven horsepower and the ability to go even higher. But the initial cost of these engines will be higher.
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