The engine was created by Dr Fritz Indra, who had been mind of Advanced Engine Development for Opel in Germany from 1985 to 1989. The engine was initially meant for race application, hence Cosworth’s participation.

‘COSCAST’ (Early) and GM (Later) mind variations

The C20XE engine’s heads arrived two notable forms. The initial versions that made an appearance for several years within the Astra GTE, Calibra and Vauxhall Cavalier/Opel Vectra from 1988 to 1991 were cast by Cosworth. These are typically more desired, because of their superior casting characteristics, within the GM version that was introduced a while in 1991 (showing up using the Astra GSi). Among the alleged characteristics from the ‘COSCAST’ mind is its natural potential to deal with porosity it was accomplished by getting rid of the existence of small air bubbles throughout the casting process. The Coscast mind could be recognized with a ‘Coscast’ logo design that is placed underneath the 3rd exhaust port. The GM mind was made by Kolben-Schmidt and featured different oil/water art galleries, which needed a set of welsch plugs to become pressed in at either finish. Incidentally, the existence of welsch plugs demonstrated to become the only way of identification for any GM manufactured mind. A strengthened form of the GM mind grew to become obtainable in the old age from the C20XE however, these supports resulted in it had more compact inlet/exhaust waterways compared to other two.

Since an engine’s oil pressure is a lot greater than its coolant pressure, oil inside a porus mind includes a inclination to progressively seep in to the cooling art galleries. An average characteristic of a porous mind is generally a ‘mayonnaise’-like substance within the coolant (dwelling around the cap). However, signs and symptoms of the porous mind possess a inclination to alter, with respect to the amount of porosity. Many C20XE operators have referred to the symptom like a curry-like residue or perhaps in more serious cases, a thick brown sludge. Throughout the porous mind debarcle, GM faced personal bankruptcy – therefore sellers unsuccessful to recall affected models. However, consequently, many companies now specialize within the repair of porous GM C20XE/LET heads – by either sleeving the affected gallery or by inserting a polymer based substance in to the porous region. Typically, the quantity of cylinder heads which were apparently porous continued to be relatively low.

The first engines used round tooth cambelts, the later used square (having a plastic pre-tensioner). You will find also subtle variations between your crankshaft, and visual difference within the pattern from the SFi airbox.


The C20XE has witnessed extensive use within motorsport. Typical ways to use the engine have ranged from hillclimb occasions, to spread out wheel racing groups. Despite wear and tear, it continues to be powerplant of preference for a lot of Formula 3 teams and it has most lately found acclaim within the Australian F3 scene where Tim Macrow, the 2007 Australian F3 champion, drove an Opel-Spiess powered vehicle to assert victory. Updated by Spiess, an F3 grade C20XE is definitely able to creating 250bhp (190kW) in the naturally aspirated form.

Many aftermarket tuners have further developed the C20XE for racing reasons. SBD Motorsport, an aftermarket tuning company located in the United kingdom, created a C20XE unit having a energy output more than 290bhp (220kW). QED Motorsport is yet another such company which have were built with a huge participation using the C20XE. They developed the very first aluminium block for that engine giving an enormous 19kg weight saving within the standard block and the opportunity of 2.3 litres of capacity! QED also developed the very first direct-to-mind throttle physiques, permitting for greater performance in highly updated motorsport programs along with other improvements. Typically, both QED Motorsport and SBD built engines have experienced use within Westfield and Caterham automobiles competing in a variety of hillclimb occasions.

The C20XE was utilized through the Chevrolet WTCC (World Touring Vehicle Championship) team and also the Lada WTCC team. The engine seemed to be a choice in Westfield kitcars.

The C20XE and C20LET variation happen to be retro installed in a number of other Vauxhall’s such as the Nova, Corsa B, Tigra, Corsa C, Vectra B and much more versions, the huge most of these conversions/transplants are thanks to the extensive selection of items obtained through a few motorsport producers.

The C20XE is another popular choice for most people that are looking a 16v engine within their small, because of its relatively compact arrangement (with gearbox) and it is affordability.

Technical information

The introduction to the engine title is the following:

C – Exhaust Pollutants Level: ECE R 83 A

20 – Displacement: 2 litre

X – Compression Ratio Threshold: X = 10.-11.5:1

E – Mixture System: Electronic Fuel Injection

The engine produces 150bhp (112kW 152PS) at 6,000 revoltions per minute, having a low optimum specific fuel use of 232 g/kWh which is the same as an optimum efficiency of 37 percent a much better efficiency than a few of the diesel engines which were available during the time of its release. The valves are positioned at 46 levels and therefore are supported by pistons with shallow valve pockets – therefore getting rid of the requirement for a shorter disadvantage fishing rod hence, permitting a appropriate compression ratio to become accomplished. Lengthy spark plugs are utilized and situated concentric towards the cylinder. Incidentally, the engine includes a square bore/stroke and shares piston dimensions using the Bugatti Veyron (86mm x 86mm).



No Of Cylinders





1998 cc (121.88 cu in)

Bore (mm)


Stroke (mm)



150bhp (111.9kW 152.1PS)/6000 revoltions per minute


196Nm (145lbft)/4800 revoltions per minute

Compression ratio


Engine management

Bosch Motronic 2.5/Bosch Motronic 2.8

Idle speed revoltions per minute


Max revoltions per minute


Firing order


Listing of cars fitted with C20XE




Opel Calibra 16V


Europe, Australia, South america

Opel Kadett E, GSI/GTE


Europe – Germany, Ireland

Opel Vectra A, GTE


Europe, Nz

Opel Astra F

1991 – 1996

Europe, Australia, Nigeria

Vauxhall Calibra 16V


United kingdom

Vauxhall Astra Mk 2, GTE


United kingdom

Vauxhall Cavalier Mk 3, GSi, SRi


United kingdom

Vauxhall Astra Mk 3, GSi

1991 – 1994

United kingdom

Lada 110

1996 –

Europe, Russia

Chevrolet Vectra GSi

1993 – 1996

South america

Holden Commodore


Australian export to Nz, Singapore, offered strictly because the Holden Berlina in individuals marketplaces


^ “C20XE conversion list”. Robbie’s Manta Site. . Retrieved 2007-07-05.

^ “”Interview with Dr Fritz indra”” (PDF). world wide web.CalibraWiki.com. . Retrieved 2008-04-13.

^ “Detailed GM & Cosworth difference photos”. Vauxsport. . Retrieved 2008-04-13.

^ “Porous GM Mind Info”. Scoobler. . Retrieved 2008-04-22.

^ “SBD Website”. 290 Taper Throttle Package. . Retrieved 2008-05-25.

^ “QED Motorsport Aluminium Block”. ‘qedmotorsport.co.uk’. . Retrieved 2009-04-07.

^ “QED Motorsport Direct-To-Mind Throttle Physiques”. ‘qedmotorsport.co.uk’. . Retrieved 2009-04-07.

^ “QED Motorsport – C20XE”. ‘qedmotorsport.co.uk’. . Retrieved 2009-04-07.

^ “”Engine Codes Described””. Topbuzz Website. 2002. . Retrieved 2007-07-05.

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