The Ford Super High Output (SHO) V8 engine was designed and built by

Ford Motor Company Ford Motor Company (commonly known as Ford) is an American multinational automobile manufacturer headquartered in Dearborn, Michigan, United States. It was founded by Henry Ford and incorporated on June 16, 1903. The company sells automobi ...

in conjunction with

Yamaha Motor Corporation is a Japanese multinational manufacturer of motorcycles, marine products such as boats and outboard motors, and other motorized products. The company was established in 1955 upon separation from Yamaha Corporation (however, Yamaha Corporation ...

for use in the 1996

Ford Taurus SHO The Ford Taurus SHO (Super High Output) is the high-performance variant of the Ford Taurus. Originally intended as a limited-production model, the SHO would be produced for the first three generations of the model line, from the 1989 to the 1999 ...

. It was based on the successful

Ford Duratec engine Duratec is a brand name of the Ford Motor Company used for the company's range of gasoline-powered four-cylinder, five-cylinder and six-cylinder passenger car engines. The original 1993 Duratec V6 engine was designed by Ford and Porsche. Ford ...

rather than its predecessor, the compact

Ford SHO V6 engine The Ford SHO V6 is a family of DOHC V6 engines fitted to the Ford Taurus SHO from 1989 to 1995. The designation SHO denotes Super High Output. Due to the engine's unusual and aesthetically pleasing appearance it is sometimes transplanted into o ...

developed by Yamaha for the 1989 Taurus SHO. The engine was retired in 1999 when production of the third-generation Taurus SHO ended.

3.4 L

The 3.4 L SHO V8 was introduced in the spring of 1996. It incorporated many of the traits of the SHO V6, including the aluminum

cylinder heads In an internal combustion engine, the cylinder head (often abbreviated to simply "head") sits above the cylinders and forms the roof of the combustion chamber. In sidevalve engines, the head is a simple sheet of metal; whereas in more modern ove ...

and 4 valves per cylinder

DOHC An overhead camshaft (OHC) engine is a piston engine where the camshaft is located in the cylinder head above the combustion chamber. This contrasts with earlier overhead valve engines (OHV), where the camshaft is located below the combustion cha ...

design, but differed with an aluminum rather than iron

block Block or blocked may refer to: Arts, entertainment and media Broadcasting * Block programming, the result of a programming strategy in broadcasting * W242BX, a radio station licensed to Greenville, South Carolina, United States known as ''96.3 ...

and no

variable length intake manifold In internal combustion engines, a variable-length intake manifold (VLIM),variable intake manifold (VIM), or variable intake system (VIS) is an automobile internal combustion engine manifold technology. As the name implies, VLIM/VIM/VIS can vary ...

. A chain is also used to time the camshafts to crankshaft instead of the belts that the SHO V6s used. The SHO V8 has a split port style intake valve setup. The primary valve is exposed all the time and has the

fuel injector Fuel injection is the introduction of fuel in an internal combustion engine, most commonly automotive engines, by the means of an injector. This article focuses on fuel injection in reciprocating piston and Wankel rotary engines. All comp ...

spraying on it, while the secondary valve is only exposed when the

Intake manifold In automotive engineering, an inlet manifold or intake manifold (in American English) is the part of an engine that supplies the fuel/ air mixture to the cylinders. The word ''manifold'' comes from the Old English word ''manigfeald'' (from the ...

Runner Control opens the secondary plates at 3400 rpm. These secondary valves are called "secondaries" by SHO enthusiasts. Power was similar too, at and of torque. Bore and stroke were identical to the Duratec 25 at , respectively. The engines shared other traits as well, and insiders report that the designs are related, though not closely. Notably, the two engines share the same

bell housing Bell housing or bellhousing is a colloquial/slang term for the portion of the transmission that covers the flywheel and the clutch or torque converter of the transmission on vehicles powered by internal combustion engines. This housing is bolte ...

pattern and 60° V angle. The 60° angle makes it compact and more suitable for

transverse Transverse may refer to: *Transverse engine, an engine in which the crankshaft is oriented side-to-side relative to the wheels of the vehicle *Transverse flute, a flute that is held horizontally * Transverse force (or ''Euler force''), the tangen ...

mounting, but it is not ideally balanced—V8s are typically 90°—necessitating the use of a counter-rotating balance shaft. Manufacturing was also a shared process. Ford manufactured the aluminum engine blocks, using a patented Cosworth process, at their

Windsor, Ontario Windsor is a city in southwestern Ontario, Canada, on the south bank of the Detroit River directly across from Detroit, Michigan, United States. Geographically located within but administratively independent of Essex County, it is the southe ...

plant, then shipped them to Japan for finishing by Yamaha. The finished engines were shipped back to the Taurus plant in

Atlanta, Georgia Atlanta ( ) is the capital and most populous city of the U.S. state of Georgia. It is the seat of Fulton County, the most populous county in Georgia, but its territory falls in both Fulton and DeKalb counties. With a population of 498,7 ...

for installation. Unlike the SHO V6, the SHO V8's

valvetrain A valvetrain or valve train is a mechanical system that controls the operation of the intake and exhaust valves in an internal combustion engine. The intake valves control the flow of air/fuel mixture (or air alone for direct-injected engines) ...

was an "interference" design, one that is shared by many engines built today, meaning that the piston will collide with the valves if the camshaft or

timing chain In a piston engine, either a timing belt (also called a ''cambelt'') or timing chain or set of timing gears is used to synchronize the rotation of the crankshaft and the camshaft. This synchronisation ensures that the engine's valves open and cl ...

fails. Due to some cam sprocket failures, the engine acquired a reputation for potentially catastrophic failure.

Cam trouble

Soon after the introduction of the SHO V8 engine, widespread problems with the cam sprockets began to surface. Yamaha had used a relatively unusual method, called "

swaging Swaging () is a forging process in which the dimensions of an item are altered using dies into which the item is forced. Swaging is usually a cold working process, but also may be hot worked. The term swage may apply to the process (verb) or ...

", of affixing the cam sprockets to the

camshafts A camshaft is a shaft that contains a row of pointed cams, in order to convert rotational motion to reciprocating motion. Camshafts are used in piston engines (to operate the intake and exhaust valves), mechanically controlled ignition systems a ...

. The cam sprockets were fastened to the hollow camshafts by forcing a metal ball which was slightly larger than the interior diameter of the camshaft through the center of the camshaft, thus expanding the metal slightly and creating a mechanical bond between the cam sprocket and the camshaft. This method proved to be inadequate, and the cam sprocket could break loose from the camshaft and spin independently from the camshaft (or "walk"). This would result in the camshaft stopping and thus not activating the valves, allowing the pistons to hit the valves, ruining the engine. The preventive measure of welding the cam sprocket to the camshaft soon proved to be a fix for engines that had not suffered such a fate yet. Another such fix is "pinning" the cam sprocket, or inserting a pin in the sprocket to keep it aligned on the camshaft. Ford issued a TSB (TSB 03-14-1) prescribing the application of Loctite to the cam sprocket to lengthen the life of the camshafts, but as SHO owners have experienced cam failure after the application of Loctite, most SHO enthusiasts do not recommend this fix.

References

External links

V8SHO.com

SHO Times, with tech tips for the SHO

SHO Club

SHO Forum
{{Ford Taurus SHO V8 SHO V8 engine Yamaha products V8 engines Gasoline engines by model

3.4 L

Cam trouble

See also

References

External links