Engine History: The Ford 4.6 liter V8

4-6 complete

(first posted 1/11/2013)

Events at Ford Motor Company have been silently spelling the end for their bread-and-butter V8 of the last two decades.  With the cancellation of the Panther platform (Ford Crown Victoria, Mercury Grand Marquis, and Lincoln Town Car) and Ford’s movement to a predominantly V6 based lineup in their F-150’s, the smooth and hardworking 4.6 liter V8 is almost extinct.

The 4.6 liter engine was the replacement for the Windsor family of Ford V8’s.  Having been introduced in the 1962 Ford Fairlane as the 221 cubic inch V8, the Windsor engines would ultimately be found in many familiar sounding sizes (289, 302, and 351) and would power everything from Falcon’s to F-350’s.  It was quite a versatile engine yet it had lived its life.  It was time to move on and Ford definitely did not allow for much confusion when it created the 4.6.

The 4.6 liter V8 was the first of what was dubbed the “Modular Engines” from Ford.  Many have misinterpreted the meaning of “modular” in describing the 4.6 and 5.4 liter V8 plus the related 6.8 liter V10; “modular” was used to describe a manufacturing process, it was not a reference to parts interchangeability.  With a bore of 90.2 mm and a stroke of 90.0 mm, this engine was very nearly a square bore.  At the time of its introduction in the 1991 Lincoln Town Car, it was the only V8 produced by a United States manufacturer to have an overhead cam valve train (Update: also the limited-production Corvette ZR-1).  After roughly forty years of American consumers having lived with overhead valve V8’s the overhead cam was a distinct difference – and perhaps part of why the 4.6 is periodically a misunderstood engine.

1991 Lincoln Full Line-02

With its introduction in the ’91 Town Car, Ford was wise.  Lincoln buyers likely didn’t care what engine their car had as long as it was smooth and made good power.  The 4.6 was certainly a smooth engine and a good power plant for a 4000 pound Lincoln.  Rated at 190 horsepower that first year, the new 4.6 created forty more peak horsepower than the outgoing 5.0 liter V8.  Fuel economy was the same with an EPA rating of 15 city and 22 highway (as per current EPA methods).

1992 Mercury Grand Marquis-05

The 4.6 would be standard equipment in 1992 for the updated Ford Crown Victoria and Mercury Grand Marquis.  This engine would be the exclusive power plant for the Panther bodied cars until their demise in 2010.

http://www.automobile-catalog.com/make/ford_usa/thunderbird_10gen/thunderbird_10gen_lx/1996.html

http://www.automobile-catalog.com/make/ford_usa/thunderbird_10gen/thunderbird_10gen_lx/1996.html

As the 1990’s unfolded, the 4.6 would continue to emerge in a greater variety of Ford Motor Company products.  1994 would see the 4.6 between the fenders of the Ford Thunderbird and Mercury Cougar where it would remain an option until the temporary termination of the Thunderbird in 1997.  A 1996 Thunderbird is shown here.

www.edmunds.com

www.edmunds.com

1996 would see the 4.6 liter arrive in the Mustang GT, much to the initial chagrin of the Mustang and 5.0 liter faithful.  In its initial appearance in the Mustang, the 4.6 liter engine was rated at 215 horsepower.

http://www.edmunds.com/ford/f-250/1997/

http://www.edmunds.com/ford/f-250/1997/

1997 would see the expanded versatility of the 4.6 with its placement in the new F-150 and the E-Series vans that had been redesigned for 1992.

While the intent of this article is to focus on the 2 valve version of the 4.6, it needs to be noted there were 3 valve and 4 valve versions offered at various times.  The 4 valve version was introduced in 1993 as the InTech V8 for use in the Lincoln Continental and Mark VIII.  As initially found in the Mark VIII, it produced 280 horsepower and 285 lb-ft of torque.  The 3 valve version was first used in the 2005 Mustang and later in the ’09 F-150.  Interestingly, the 3-valve was rated at 300 horsepower in the Mustang and 292 horsepower in the F-150; both were rated at 320 lb-ft of torque.  That should be viewed as a testament to refinement and ever-expanding engine technology.

In the interest of full disclosure, this author owns or has owned four vehicles powered by the 4.6 liter V8; a 1992 Crown Victoria, a 1996 Thunderbird, a 2001 Crown Victoria, and a 2007 F-150.  These engines were anywhere from brand new (in the case of the Thunderbird) to having 140,000 miles on the ’92 at the time it was sold.

The general driving characteristics of the 4.6 were remarkably different from what most operators were accustomed.  Let’s look again at the ’91 Town Car as compared to the ’90 Town Car.  The ’91 is rated at 190 horsepower whereas the ’90 generated 150 horsepower from its 302 cubic inch (5.0 liter) V8.  However, the ’90 generated its peak horsepower at 3,200 rpm, a full 1,000 rpm lower than the ’91.  Similarly, when discussing torque, the ’90 had a 10 lb-ft advantage over the ’91; the ’90 also generated its peak torque at 2,000 rpm whereas the ’91 generated its peak at 3,200 rpm.

The author has observed several instances of people’s misperception of the capabilities of the 4.6 liter in pickup applications – where torque truly is king.  Recently, he was approached by a field employee requesting a 3/4 ton pickup.  As this employee would soon have a periodic need to pull a 4,000 pound trailer, the employee was concerned about damaging his 4.6 liter powered pickup.  Despite providing Ford’s engine rating of 248 horsepower and the towing capacity chart for ’08 F-150’s to the employee, there was still an above average level of skepticism.  A field visit to take turns pulling this trailer resulted in the employee being convinced while saying, “that’s a really small engine; it’s a lot stronger than I thought.”

As introduced in the ’97 F-150’s, the 4.6 made 220 horsepower at 4,750 rpm with maximum torque of 265 lb-ft at 4,000 rpm.  When compared to the 5.0 liter in the 1996 F-150, the 4.6 has a 21 horsepower advantage at 550 more rpm’s; torque is within 5 lb-ft at 270, but it is fully available at only 2,400 rpm.  By current measuring standards, the EPA rated the 4.6 liter in model year 1997 two-wheel drive applications as being capable of 20 mpg – 3 mpg better than the 5.0 liter V8 from 1996.

The 4.6 simply revs more to generate its power.  For many accustomed to the immediate torque of pushrod V8’s, this was a distinct difference.

While the 4.6 is a stout engine, its 20+ year production run hasn’t been free of blemishes.

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