Editing Ford SHO V8 engine

{{Refimprove|date=October 2009}}
{{Infobox automobile engine
| name          = Ford SHO V8
| image         = V8 32 valve.JPG
| manufacturer  = [[Ford Motor Company]] and [[Yamaha Motor Corporation]]
| production    = 1996–1999
| configuration = [[Naturally aspirated]] 60° [[V8 engine|V8]]
| displacement  = {{cvt|3392|cc|L CID|1|order=flip}}
| bore          = {{cvt|82.4|mm}}
| stroke        = {{cvt|79.5|mm}}
| block         = Aluminum
| head          = Aluminum
| valvetrain    = [[Multi-valve#Four valves|32-valve]] [[DOHC]]
| fueltype      = 93 Octane (Premium)Gasoline
| fuelsystem    = [[Fuel injection]]
| coolingsystem = [[Radiator (engine cooling)|Water-cooled]]
| power         = {{cvt|235|hp|0}} at 6100&nbsp;rpm
| torque        = {{cvt|230|lbft|0}} at 4800&nbsp;rpm
| compression   = 10.0:1
| predecessor   = [[Ford Mondeo V6 engine#Duratec 25|Duratec 25]]<br />[[Ford SHO V6 engine|SHO V6]]
| successor     = [[Ford Modular engine#4-valve|''InTech'']] (FWD V8)<br>[[Ford EcoBoost engine#3.5 L|Ecoboost V6]] [[Twin-turbo]]<br>[[Volvo B8444S engine]] (Yamaha)
}}

The '''Ford Super High Output (SHO) V8 engine''' was designed and built by [[Ford Motor Company]] in conjunction with [[Yamaha Motor Corporation]] for use in the 1996 [[Ford Taurus SHO]]. It was based on the successful [[Ford Duratec engine#Mondeo V6|Ford Duratec engine]] rather than its predecessor, the compact [[Ford SHO V6 engine]] 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&nbsp;L SHO [[V8 engine|V8]] was introduced in the spring of 1996. It incorporated many of the traits of the [[Ford SHO V6 engine|SHO V6]], including the aluminum [[cylinder heads]] and [[Multi-valve#Four valves|4 valves per cylinder]] [[DOHC]] design, but differed with an aluminum rather than iron [[engine block|block]] and no [[variable length intake manifold]]. A chain is also used to time the [[camshaft]]s 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]] spraying on it, while the secondary valve is only exposed when the [[Intake manifold]] Runner Control opens the secondary plates at 3400&nbsp;rpm. These secondary valves are called "secondaries" by SHO enthusiasts. Power was similar too, at {{cvt|235|hp|kW|0}} and {{cvt|230|lbft|Nm|0}} of torque.<ref name="GeneralSpecs">{{cite web |title=General Specifications|url=http://www.v8sho.com/SHO/genspecs.html}}</ref>

Bore and stroke were identical to the [[Ford Mondeo V6 engine#Duratec 25|Duratec 25]] at {{cvt|82.4|and|79.5|mm|2}}, 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]] pattern and 60° V angle. The 60° angle makes it compact and more suitable for [[transverse engine|transverse]] 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]] plant, then shipped them to Japan for finishing by Yamaha. The finished engines were shipped back to the Taurus plant in [[Atlanta, Georgia]] for installation.

Unlike the SHO V6, the SHO V8's [[valvetrain]] 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 belt (camshaft)|timing chain]] 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]]", of affixing the cam sprockets to the [[camshafts]].<ref name="CamSprocketInfo">{{cite web |title=Cam Sprocket - Part 2|url=http://www.v8sho.com/SHO/camsprocket2.htm}}</ref> 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.<ref name="CamSprocketPhotos">{{cite web |title=More Cam Sprocket Photos|url=http://www.v8sho.com/SHO/MoreCamSprocketPhotos.htm}}</ref> 

This method proved to be inadequate, and the cam sprocket could break loose from the camshaft and spin independently from the camshaft (or "walk").<ref name="NearFailure">{{cite web |title=Picture Evidence of an Almost Cam Failure|url=http://www.v8sho.com/SHO/Picture%20Evidence%20of%20an%20Almost%20Cam%20Failure.htm}}</ref><ref name="CamSprocketAutopsy">{{cite web |title=Cam Sprocket Autopsy|url=http://www.v8sho.com/SHO/CamSprocketAutopsy.htm}}</ref> 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.<ref name="CamSprocketSkeptic">{{cite web |title=Still Skeptical about Cam Welding|url=http://www.v8sho.com/SHO/StillskepticalaboutCamWelding.htm}}</ref> 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,<ref name="Loctite">{{cite web |title=Loctite TSB 03-14-1|url=http://www.v8sho.com/SHO/LoctiteTSB03141.htm}}</ref> but as SHO owners have experienced cam failure after the application of Loctite,<ref name="LoctiteFailure1">{{cite web |title=Ernie Roberts - Loctited - Cam Failure #272|url=http://www.v8sho.com/SHO/ErnieRobertsLoctitedCamFailure272.htm}}</ref> most SHO enthusiasts do not recommend this fix.<ref name="LoctiteComments">{{cite web |title=Owner Comments on Loctite TSB 03-14-1|url=http://www.v8sho.com/SHO/OwnerCommentsonLoctiteTSB03141.htm}}</ref><ref name="LoctiteComments2">{{cite web |title=Analysis of Loctite Effect on V8SHO Camshaft Failures|url=http://www.v8sho.com/SHO/Bruce/Camfail_to_TW0904041.pdf}}</ref>

== See also ==

* [[Ford Taurus SHO]]
* [[Ford SHO V6 engine]]
* [[List of Ford engines]]
* [[List of Ford bellhousing patterns]]

== References ==

{{reflist}}

== External links ==

* [http://www.v8sho.com V8SHO.com]
* [http://www.shotimes.com/php-bin/ SHO Times, with tech tips for the SHO]
* [http://www.shoclub.com SHO Club]
* [http://www.shoforum.com SHO Forum]

{{Ford Taurus}}

[[Category:Ford engines|SHO V8]]
[[Category:Ford Taurus|SHO V8 engine]]
[[Category:Yamaha engines]]
[[Category:V8 engines]]
[[Category:Gasoline engines by model]]