Just about everything. For starters, mod engines are overhead cam, so there is no need for pushrods. Modular engines share the same basic design in blocks, aluminum heads and other key components. Advantages associated with Ford's modular engine series are: increased power, durability, fuel efficiency, and reduced noise, vibration and harshness. In most cases, push-rods have a lot of power on the bottom to mid sections of the powerband, and begin to drop of quickly after it's peak, and have lower power levels at high RPM's. Modular engines often have anemic power levels on the bottom, but have good strong power levels usually starting in the mid-RPM powerband and usually continue to grow or stay close to peak all the way through the high RPM powerband, some stay strong nearly to the redline. This is not always true, but is generally correct for this situation.
4.6L SOHC/4.6L DOHC/5.4L SOHC
In 1991, Ford unleashed a new era of muscle, one that is propelling us into the future. The modular engine focuses on low friction, excellent sealing and increased block stiffness. The design results in an extremely smooth running engine using aluminum heads and having all accessories rigidly mounted to the engine. Both the engine block and head are machined to close tolerances to produce a very precise assembly. The head bolts of modular engines actually extend past the cylinder bores into the bearing webs, eliminating bore distortion and providing a better head gasket seal. The sophisticated overhead cam design uses roller finger followers to lower friction and increase the RPM potential of the engine. On the bottom end, the deep skirt engine block and cross-bolted main caps contribute to a higher rigid assembly. Two engine plants manufacture Modular engines; Romeo produces all passenger car versions and Windsor produces the Modular Truck engines. HereÕs a brief description of Modular V-8 engines.
4.6L SOHC
The 4.6L SOHC (2V) was first introduced in 1991. This engine is the basis for all modular engines as is used in passenger cars as well as trucks. The block is cast iron with a nodular crankshaft, while the heads are aluminum using an in-line valve design with 1 intake and 1 exhaust valve per cylinder. All passenger cars have press fit piston pins, while all truck engines have full floating piston pins to improve durability.
4.6L DOHC
The 4.6L DOHC (4V) was first introduced in the Mark VIII; however, in 1996 a similar version of this engine found its calling in the Mustang Cobra. The aluminum block and four-valve head make for a powerful combination producing 305 HP @ 7000 RPM. Internally the 4 bolt, cross-bolted main bearing caps provide the support necessary to easily handle the high RPM potential of the forged steel crankshaft. This engine uses hypereutectic pistons with full floating piston pins and upgraded connecting rod assemblies to improve durability.
5.4L SOHC
The 5.4L SOHC (2V) "Triton" engine released in trucks for 1997 is producing favorable reactions. This engine has a cast iron block, forged steel crankshaft, full floating piston pins and special 6000 RPM connecting rods. It is the 5.8L "pushrod engine" replacement.
Take care,
-Chris
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