Editing Cosworth DFV (section)

====DFZ====
{{Infobox automobile engine
| name = [[Cosworth]] DFZ<ref name="Engine Ford Cosworth • STATS F1"/>
| image = 
| manufacturer = {{flagicon|UK}} [[Ford Motor Company|Ford]]-[[Cosworth]]
| production = 1987–1988
| configuration = [[V8 engine|V8]], [[naturally aspirated|naturally-aspirated]], 90° cylinder angle
| displacement = {{cvt|3494|cc|L|1|order=flip}}
| bore = {{cvt|90|mm|in|1|lk=on}}
| stroke = {{cvt|68.65|mm|in|1|lk=on}}
| block = [[Aluminium]] alloy
| head = [[Aluminium]] alloy
| valvetrain = 32-valve, [[DOHC]], four-valves per cylinder
| power = {{cvt|575-590|hp|kW|0|lk=on}}
| torque = {{cvt|320|lbft|Nm|0|lk=on}}<ref name="spicerparts.com">{{cite web |url=https://spicerparts.com/calculators/horsepower-torque-calculator |title = Horsepower and Torque Calculator{{!}} Spicer Parts}}</ref>
| oilsystem = Dry sump
| weight = {{cvt|155|kg|lb|0|lk=on}}
| fuelsystem = Electronic and mechanical indirect fuel injection
| fueltype = [[Gasoline]]
}}
The announcement at end of the {{F1|1986}} season that turbocharged cars would be banned from {{F1|1989}}, and the introduction of the [[Jim Clark Cup]] and [[Colin Chapman Trophy]] championships for naturally aspirated cars for {{F1|1987}}, prompted Cosworth to revive their elderly engine design. This resulted in the DFZ, essentially an updated version of the final DFY design. However, the capacity increase for the new 3.5L [[naturally aspirated]] formula running alongside the 1.5L turbos in 1987 allowed Cosworth to increase the power output of the unit to {{cvt|575|bhp|kW PS|0}}.<ref name="motorsport02" /> The engine was intended as a temporary measure to tide smaller teams over until the turbos were banned at the end of the {{f1|1988}} season. [[Tyrrell Racing|Tyrrell]], [[Automobiles Gonfaronnaises Sportives|AGS]], [[March Engineering|March]], [[Lola Cars|Lola]] and [[Enzo Coloni Racing Car Systems|Coloni]] chassis were all powered by Cosworth in 1987. [[Jonathan Palmer]] of Tyrrell eventually won the drivers' Jim Clark Cup, and his team took the constructors' laurels in the Colin Chapman Trophy. The engine remained in service with minor teams until the end of 1988 and development saw a slight power increase to {{cvt|590|bhp|kW PS|0}}. The DFZ did not race in Formula One beyond 1988 as the general release of the DFR engine made it obsolete.

The engine did however have a second brief lease of life in sportscar racing, when the FIA announced plans to transition towards using 3.5&nbsp;L F1-style engines in [[Group C]] in the early 1990s. In 1990 [[Spice Engineering]] adapted its existing Group C design to take a 3.5L DFZ instead of the previously used 3.3&nbsp;L DFL engine. However the new engine caused significant problems due to vibration, which resulted in the breakage of components and a significant increase in running costs - [[Gordon Spice]] estimated that the DFZ-powered car was about four times more expensive to run than the DFL-engined one.<ref>{{cite web |url=http://www.autosport.com/premium/feature/4734/the-death-of-group-c/ |title=The death of Group C |last1=Cooper |first1=Adam|date=24 August 2012 |website=[[autosport.com]] |access-date=2 April 2016}}</ref> The DFZ was successfully used in FIA Cup class racing in 1992, with that low-powered class being the last appearance of the DFV family in sportscar racing.