1996 Mustang Engine Information – 281 cubic inch V-8 (4.6 L Ford Modular V8)
Ford’s Modular 4.6L DOHC/SOHC V8
1996-1998 Cobras were powered by Ford’s modular 4.6L DOHC V8 which produced an advertised 305 hp (227 kW) and 300 lb·ft (410 N·m) of torque.
The 4.6 was a modern engine and much more advanced than the outgoing 302. Better refinement, cleaner emissions and modern engineering was the initial goal of offering the new V8. To say this engine is new is an understatement. Even the manufacturing processes were a radical departure from the old days.
The 4.6-litre V8 installed in the 1996 Mustang GT featured a chain driven single over-head camshaft operating two valves per-cylinder located in aluminum cylinder heads. The valves were actuated by hydraulic roller finger followers, eliminating the need for valve adjustments. Ford used very long bolts to clamp the cylinder head to the block. These special bolts reduced distortion of the cylinder bores therefore providing improved sealing.
The 90-degree cast iron engine block was deeply skirted with cross bolting for strength in order to lower engine noise and vibration and increase durability. A nodular cast iron crankshaft was used and bolted to it were a nifty set of connecting rods. These connecting rods were made of powdered metal and manufactured with the rod and cap as a one-piece unit. The large end of the rod is then cracked off thus separating the rod from the cap. This ensures that the rods and caps aren’t mismatched or installed backwards and are always an exact fit with one another. To keep everything lubricated and cool Ford used an integrated oil cooling system that used engine coolant to keep temperatures in check and potentially extend engine life.
A set of Teflon-coated hypereutectic pistons were press fit to the rods. Hypereutectic pistons, cast from high-silicon aluminum alloy are strong, light weight and offer a lower coefficient of thermal expansion; meaning they do not expand much with heat. This allowed engineers to run tighter tolerances for better oil control and consistent cylinder sealing. The modular 4.6-litre engine was not only a high tech modern engine that ran smooth; it was built to last and has proven to be an extremely reliable power plant with many examples lasting 500,000 plus kilometers without a rebuild.
The power steering pump, alternator, air-conditioning compressor and all idler and tension pulleys were mounted directly to the engine block. By doing this Ford eliminated all the brackets for the accessories making for a more compact engine assembly while also eliminating some unwanted engine noise and vibration at the same time. Ford also reduced maintenance costs for owners be installing long life platinum spark plugs, a 100,000 mile accessory drive belt, a distributor-less coil-on-plug electronic ignition system and the newly mandated OBD II diagnostic system.
Ford needed to do some reengineering in order to install the taller modular engine into the engine bay. The front crossmember and engine mounts were redesigned to allow the new V-8 to sit lower in the engine bay. The lower control arms were repositioned along with the steering rack and a new more compact brake booster was devised that used hydraulic pressure from the power steering pump instead of engine vacuum for brake assist. As a consequence of these changes the Mustang’s handling was improve with the car now feeling lighter and more responsive.
As silky and modern as the 4.6 might have been, many enthusiasts felt that the engine was a step backwards performance wise even though it produced the same horsepower and torque figures as the outgoing 5-litre. The problem was in the way the new engine produced its power. Overhead-valve engines like the 5-litre produce much of their torque, the twisting motion that accelerates the vehicle, at low engine speeds. These engines usually feel very powerful since they feel as if they are not working very hard to produce power. Overhead-cam engines such as the 4.6-litre are freer revving engines and produce power at higher engine revolutions. Therefore the feeling of instant thrust isn’t as pronounced since the engine has to ‘spool-up’ a little more to achieve its peak horsepower and torque. The refinement of the modular motor even further masked the sensory experience of speed; it was almost too smooth and quiet. This was perfect for a Lincoln Town Car or full sized Ford or Mercury for which the engine was originally installed in; but not so much for a performance car where most noises and vibrations are considered part of the driving experience.
Complicating matters even more was the fact that there was virtually no aftermarket support for the modular engine and aftermarket parts suppliers were a little slow at introducing high performance upgrades for the new engine. While most buyers could have cared less, hard core Mustang performance junkies were left out in the cold, twitching and anxious for their next fix. Eventually as time marched on the aftermarket industry embraced the new engine and enthusiasts began to appreciate the modular engine’s high-revving attributes and its potential to make colossal amounts of horsepower.