As vintage Ford enthusiasts, many of us have been slow to embrace Ford's newest engine technology--the 4.6 and 5.4 SOHC and DOHC Modular V-8 engines. We like the familiarity of the small-block Ford, the FE big-blocks, the Cleveland, the 385-series fat-blocks, and even the old Y-block V-8s. We grew up on rocker arms, pushrods, and real iron, and as a result, we've never published much on the Modular V-8 engine family.
But we're into more progressive thinking these days at Mustang & Fords, which is now under the guidance and direction of Editor Mark Houlahan (whose most recent gig was senior technical editor at 5.0 Mustang & Super Fords), so it's time to learn as much as we can about Ford's newest generation of overhead cam V-8 engines. We visited Power Heads/Modular Racing in California for a look at Ford's venerable Modular V-8. We also gave a shout to the Modular fanatics at Ford Racing, Sullivan Performance, and True Blue Performance to answer some of our questions.
The Modular V-8 engine isn't new. It was introduced in the '91 Lincoln Town Car 15 years ago. Then it appeared a year later in the redesigned '92 Ford Crown Victoria and Mercury Grand Marquis. In 1994, it was introduced in the Thunderbird and Cougar; in 1996, it debuted in the Mustang GT and SVT Cobra. Early in 1996, the Modular V-8 found its way into the redesigned '97 F-series truck line; after that, the E-series vans, as both a V-8 and a V-10; then, the all-new Super Duty F-250/350, as a V-8 and a V-10.
The Modular V-8 is as deeply entrenched into the Ford psyche' today as our pushrod V-8s were during the '60s and '70s. It is very much at home with Ford performance enthusiasts, and likely here to stay for a long time to come. For 2005, Ford has introduced its newest version of the Mod motor with a three-valve cylinder head and cast-aluminum cam covers. The three-valve head can be found in the all-new '05 Mustang GT on top of the 4.6 short-block, and the '04-'05 5.4 F-150 and Expedition. This head has made a huge difference in low-end torque, making the 4.6 and 5.4 V-8s snappier down low where it counts--at the traffic light.
The Modular V-8 didn't get its name from its design. The name was derived from its manufacturing plant protocol--Modular--because the engine plant can be changed out in a matter of hours to produce different versions of this engine family. That said, the Modular V-8 and V-10 engine family is certainly different from our proven pushrod V-8 engines of yore. for one thing, it is huge, impossible to fit into a classic Mustang or Fairlane without significantly modifying the front end. However, it's a nice fit for the big Fords--the Galaxies and Customs. It's also a comfortable fit for the classic F-series pickups. Sit a 4.6 Mod motor next to a Boss 429, and you will find the 4.6 and 5.4 engines are larger in every respect. They're large, yet small, with displacements of 281 ci and 345 ci, respectively. What makes these engines so large is their wide overhead cam cylinder heads. In this first half of our look into the Modular engine family, we'll get you acquainted with the Modular short-block and its internal nuances. Next month, we'll wrap things up with a look at cylinder heads and induction for the Modular family.
This is the 4.6 SOHC V-8 engine in the raw, void of its timing and cam covers. It is an elaborate design with chain-driven, single overhead cams on each head. | 
According to Len Bertrand at Lentech Automatics, very early 4.6 SOHCs have the same bellhousing bolt pattern as the vintage 289/302/351W small-blocks. The engine bolts right to the AOD, AODE, C4, and even the FMX, if you can find one (look for this engine in '92 Crown Vics or Grand Marquis'). |
With its heads removed, the 4.6 SOHC engine appears to be small--a smallish cross-bolted main cap block with broad decks to accommodate the huge aluminum cylinder heads. A huge, V-shaped timing chain cover hides the entire front of the block. Missing here is the oil pump, which fits around the crankshaft. Also note the central valley is dry with both the SOHC and DOHC engines. In the center of the valley is a provision for the screw-in knock sensor. | |
SOHC Engines
When Ford introduced the 4.6 SOHC V-8 in 1991, it was vastly different than any Ford V-8 we had ever seen; it hardly seemed a Ford powerplant. Yet, like the old FE-series 427, it had block main skirts and cross-bolted main caps for rigidity. And like the 427 SOHC, it had a single overhead cam design and a whole lot of chain, which made it larger. Outside of those two features, the 4.6 SOHC V-8 really was a different engine altogether.
Both the SOHC and DOHC sport cross-bolted main bearing caps. Early versions of this engine have four cross-bolted caps. Later versions from '96-and-up have five cross-bolted caps. Early versions are jackscrewed main caps. Later versions have doweled, precision-fit, cross-bolted main caps. The casting number can be found midblock.
The 4.6 SOHC sports a rigid iron block capable of handling high-rpm operation and channeling a lot of power across its lean looking crankshaft with knife-blade counterweights. From front to rear, the Modular V-8 is shorter than the small-blocks and big-blocks it replaces. From side to side, it's much wider. In full dress, it tends to be heavier, around 600 pounds. It has nothing in common with any of the pushrod V-8s already mentioned. What's more, the Modular V-8 doesn't enjoy the same kind of interchangeability as its predecessors. The Modular engines tend to be different from one plant to another, from one model year to the next, and from one carline to the other. It takes a solid understanding of this engine and its many castings to build it and make power.
When Modular V-8 production began 15 years ago, there was one engine plant: Romeo, Michigan, the old Ford tractor plant outside of Detroit. in 1997, Ford added a second Modular V-8 plant at Windsor, Ontario, to produce 4.6 and 5.4 SOHC engines for primarily trucks. Eventually, the Windsor plant would produce Mod motors for an even greater number of car lines. If may surprise you to know the Windsor engines are considerably different than their Romeo counterparts. Very little interchanges from one plant to the other.
DOHC Engines
In 1993, Ford introduced the 4.6 DOHC engine in the Lincoln Mark VIII. What made the 32-valve Modular V-8 different was its all-aluminum construction. This engine witnessed exclusive use in Lincolns until 1996 when it was then introduced in the SVT Mustang Cobra. The DOHC approach was carried over to the Lincoln Navigator in the late '90s with the 5.4 DOHC V-8 with an iron block and aluminum heads. These DOHC engines make excellent powerhouses for vintage Fords, thanks to their lightweight, cross-bolted main cap design.
This engine is terrific looking for a vintage Ford engine compartment because it is massive, with extra-wide cylinder heads and cam covers. It is right at home in a full-size Galaxie or Marauder, and worthy of engine compartment indigestion in a Mustang or Fairlane.