Editing Repco (section)

==Formula 5000 engines==
===Repco Holden===
Repco also developed and built the Repco-Holden Formula 5000 engine for [[Formula 5000]] racing. Repco used the block and head castings of the [[Holden V8 engine|Holden 308 V8 engine]] as its basis,<ref>Repco advertisement, "Guide to the Gold Star, Supplement to Racing Car News, August 1972, p. xvi</ref> but it featured many modifications including [[Lucas Industries|Lucas]] [[fuel injection]], dual-coil [[Bosch (company)|Bosch]] ignition and more than 150 special components designed by Repco.<ref>[http://www.sergent.com.au/tas71s.html 1970 Tasman Series] {{webarchive|url=https://web.archive.org/web/20091007232120/http://www.sergent.com.au/tas71s.html|date=7 October 2009}} Retrieved from sergent.com.au on 13 September 2009</ref> The engine first tasted success in the [[1970 Australian Grand Prix]] that was won by [[Frank Matich]] driving a Repco-Holden powered [[McLaren M10B]].

The engine was then used extensively in racing vehicles including cars competing in the [[Tasman Series]], the [[Australian Drivers' Championship]], the [[Australian Sports Car Championship]] and the [[Australian Sports Sedan Championship]].

By 1976, power for the {{cvt|4940|cc|L|1|order=flip}} Repco-Holden V8 (a slightly smaller cubic capacity than the base {{cvt|5044|cc|L|1|order=flip}} Holden) was rated at approximately {{cvt|500|bhp|kW PS|0}}. This compared to approximately {{cvt|520|bhp|kW PS|0}} for the {{cvt|4958|cc|L|1|order=flip}} [[Chevrolet small-block engine|Chevrolet]] V8 and {{cvt|470|bhp|kW PS|0}} for the {{cvt|4931|cc|L|1|order=flip}} Repco Leyland V8.

Due to the success of the Repco-Holden V8, [[Holden]] enlisted Repco to carry out the development work (on the [[dynamometer]] only, according to [[Holden Dealer Team]] boss [[Harry Firth]]) on Holden's 308 engine for its [[Holden Torana#LH|Torana SL/R 5000]] that was released in 1974. Firth believed that developing the engine on the dyno and not on the race track saw continual problems for the engine such as oil surge—especially in touring car racing. He also claimed to have already cured the oil problems while developing the still-born [[Holden LJ Torana GTR XU-1|Torana GTR XU-1]] V8 in [[Supercar scare|1972]] and that Holden ignored his warnings about the Repco engine.

The list of Repco-Holden's Formula 5000 engine race, championship and series wins includes:

[[Australian Grand Prix]]
* [[1970 Australian Grand Prix|1970]] – [[Frank Matich]], [[McLaren M10B]]<ref>[https://trove.nla.gov.au/newspaper/article/110441216 A triumph for Repco engine] ''Canberra Times'' 1 December 1970 p. 14</ref>
* [[1971 Australian Grand Prix|1971]] – Frank Matich, [[Matich A50]]
* [[1976 Australian Grand Prix|1976]] – [[John Goss (racing driver)|John Goss]], [[Matich A53]]

[[Australian Drivers' Championship]]
* [[1972 Australian Drivers' Championship|1972]] – [[Frank Matich]], Matich A50
* [[1973 Australian Drivers' Championship|1973]] – [[John McCormack (racing driver)|John McCormack]], [[Elfin MR5]]
* [[1975 Australian Drivers' Championship|1975]] – John McCormack, [[Elfin Sports Cars|Elfin MR6]]

[[New Zealand Grand Prix]]
* 1973 – John McCormack, Elfin MR5
* 1974 – John McCormack, Elfin MR5

[[Australian Sports Car Championship]]
* [[1975 Australian Sports Car Championship|1975]] – [[Garrie Cooper]], [[Elfin Sports Cars|Elfin MS7]]

[[Australian Sports Sedan Championship]]
* [[1980 Australian Sports Sedan Championship|1980]] – Tony Edmondson, [[Alfa Romeo Alfetta GTV]]

[[Australian Tourist Trophy]]
* [[1976 Australian Tourist Trophy|1976]] – Stuart Kostera, Elfin MS7

[[Toby Lee Series]]
* 1974 – John McCormack, [[Chrysler Valiant Charger|Chrysler Charger]]

===Repco Leyland===
After the initial success of the Repco Holden engine, Australian racer John McCormack began looking for a cheaper and lighter alternative to the Holden and Chevrolet engines. In 1974, he and former [[Repco Brabham]] engineer [[Phil Irving]] found what they were looking for in the 4.4L alloy block [[Rover V8 engine]] that powered the [[Leyland P76]]. In its standard form, the {{cvt|4414|cc|L|1|order=flip}} engine produced approximately {{cvt|200|bhp|kW PS|0}}. After being highly modified by Repco to be upsized to {{cvt|4931|cc|L|1|order=flip}}, and after much development over three years, the Repco-Leyland V8 eventually produced around {{cvt|470|bhp|kW PS|0}} at its peak in 1977, which although a fair bit less than the power on offer from the Repco Holden and Chevrolet engines, was offset by the fact that it weighed only {{cvt|160|kg|lb|1}} compared to the cast iron blocks of the Holden ({{cvt|220|kg|lb|1}}) and the Chevrolet ({{cvt|231.5|kg|lb|1}}) engines.

In 1976, McCormack had purchased the [[1973 British Grand Prix|1973]] [[British Grand Prix]] winning [[McLaren M23]] (Chassis No. M23-2)<ref>[https://primotipo.com/2014/07/24/macs-mclaren-peter-revson-dave-charlton-and-john-mccormacks-mclaren-m232/ Mac’s McLaren: Peter Revson, Dave Charlton and John McCormack’s McLaren M23/2…]</ref> from South African racer [[Dave Charlton]] and modified the car for Formula 5000 racing (the car was bought with all spares, but no engine). He chose the Repco Leyland primarily because its weight was comparable to the {{cvt|168|kg|lb|1}} [[Cosworth DFV]] that the car had originally been designed to use and thus wouldn't upset the more finely tuned handling of the former [[Formula One]] race winner as would the heavier Holden or Chev V8s.

While McCormack would win the [[1977 Australian Drivers' Championship]] with the Repco-Leyland, the engine was known to be on the brittle side and lacked the reliability of the Chevrolet and Holden V8s.

The list of Repco-Leyland's Formula 5000 engine race, championship and series results includes:
* [[1976 Australian Drivers' Championship]] – 3rd (1 win @ [[Calder Park Raceway|Calder Park]])
* [[1977 Rothmans International Series]] – 9th
* [[1977 Australian Drivers' Championship]] – 1st (1 win @ [[Surfers Paradise International Raceway|Surfers Paradise]])
* [[1977 Australian Grand Prix]] @ [[Oran Park Raceway|Oran Park]] – DNF (engine)
* [[1978 Australian Drivers' Championship]] – 2nd (1 win @ Oran Park)
* [[1978 Australian Grand Prix]] @ [[Sandown Raceway]] – DNF (engine) – <small>''Pole Position''</small>
* [[1979 Rothmans International Series]] – 9th
* [[1979 Australian Grand Prix]] @ [[Wanneroo Park]] – DNF (gearbox)