Difference between revisions of "X25XE"

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[[Image:DCP 0009.jpg|thumb|right|212px|The C20XE Engine with 'Vauxhall' spark plug cover]]
{{Mergeto|GM 54-Degree V6 engine|Talk:GM 54-Degree V6 engine#Merger proposal|date=January 2008}}
{{Refimprove|date=June 2008}}
{{Infobox Automobile engine
| image        =
| name          = X25XE
| aka          =
| manufacturer  = [[GM Europe|General Motors Europe]]
| type          = [[V6 engine|V6]] [[petrol engine]]
| production    =
| predecessor  = [[C25XE]]
| successor    = [[Y26SE]]
| bore          = {{auto mm|81.6|3}}
| stroke        = {{auto mm|79.6|3}}
| displacement  = {{auto cc|2498|1}}
| length        =
| diameter      =
| width        =
| height        =
| weight        =
| block        = [[cast iron]]
| head          = [[aluminium alloy]]
| valvetrain    = 2x [[DOHC]]
| fuelsystem    =
| fueltype      = [[gasoline|unleaded petrol]]
| oilsystem    = [[wet sump]]
| coolingsystem = [[water]]/[[antifreeze]]
| power        = {{convert|125|kW|hp}}
| specpower    =
| torque        = {{auto Nm|227|0}}
| compression  = 10.8:1
| fuelcon      =
| specfuelcon  =
| oilcon        =
}}
{{Infobox Automobile engine
| image        =
| name          = X30XE
| aka          =
| manufacturer  = [[GM Europe|General Motors Europe]]
| type          = [[V6 engine|V6]] [[petrol engine]]
| production    =
| predecessor  =
| successor    = [[Y32SE]]
| bore          = {{auto mm|86|3}}
| stroke        = {{auto mm|85|3}}
| displacement  = {{auto cc|2960|1}}
| length        =
| diameter      =
| width        =
| height        =
| weight        =
| block        = [[cast iron]]
| head          = [[aluminium alloy]]
| valvetrain    = 2x [[DOHC]]
| fuelsystem    =
| fueltype      = [[gasoline|unleaded petrol]]
| oilsystem    = [[wet sump]]
| coolingsystem = [[water]]/[[antifreeze]]
| power        = {{convert|155|kW|hp}}
| specpower    =
| torque        = {{auto Nm|270|0}}
| compression  = 10.8:1
| fuelcon      =
| specfuelcon  =
| oilcon        =
}}
The '''X25XE''' is a [[GM Europe|General Motors Europe]] (GM) [[petrol engine]].  It is a 2498 cc (2.5L) 24 valve, [[Overhead camshaft#Double overhead camshaft|DOHC]] [[V6 engine]], producing, in standard form {{convert|125|kW|hp}} (170 PS).


The '''C20XE''' is a DOHC, inline 4 cylinder [[Family II]], [[General Motors]] engine. It has a capacity of 1998 cc (2.0L) and develops {{convert|110|kW|PS bhp|0|abbr=on}}.
The breakdown of the engine name <ref>Topbuzz, "Engine Codes Explained", ''Topbuzz Website'', 2002. Accessed 9 Dec 2006 [http://topbuzz.co.uk/info/engine_codes/engine_codes.htm]</ref> is as follows:


The C20XE came into production as an evolution of the 20XE engine. Incidentally, the 20XE engine was a further development of the 1987 model 8v 20NE engine. The 20XE(Bosh Motronic ML 4.1) first saw the light of day in 1987 with the launch of the Opel Kadett GSI 16v, introducing 16 valve technology and Knock Sensors to Opel/Vauxhall lineup. In 1988 the C20XE was introduced, with a {{convert|150|hp|abbr=on}} output compared to the earlier 20XE's {{convert|157|hp|abbr=on}}. This was due to new emission standards, which forced manufacturers to specify their cars with a catalytic converter and a lambda sensor - this requirement permitted the fitment of a new generation of Engine Management Systems(Bosch Motronic 2.5).
'''X''' - Exhaust Emissions Level: 94/12/EC, stage 2<br>
'''25''' - 2.5 Litre displacement<br>
'''X''' - Compression Ratio - 10.0-11.5:1<br>
'''E''' - Mixture System - Injection


The C20XE engine featured in many [[General Motors]] vehicles including some models of the Vauxhall/Opel [[Astra]]/[[Kadett E]] and the Vauxhall/Opel [[Calibra]]/[[Cavalier]]/[[Vectra]]. Enthusiasts commonly refer to this engine as the 'Red Top' (or just 'XE') because of the appearance of the red L-shaped spark plug cover.(This was red, but black colours are available, and the rocker cover was only available in silver). <ref>{{cite web | url = http://www.mantamagic.com/red%20top%20conversion%20list.htm | title = C20XE conversion list | work = Robbie's Manta Site | accessdate = 2007-07-05}}</ref> At the time of its launch, this engine was something of a milestone unit in Europe and was widely used in motorsport in many specialist race versions. It is still revered and sought after by enthusiasts today nearly two decades later. A version of the engine also appeared in [[Lada]] cars in the late 1990s.
In the early 1990s, GM identified the need for a modern, lightweight and compact power plant to replace its ageing [[straight-6]] engine range.  This [[internal combustion engine|engine]] needed to be compact, to allow its use in [[front-wheel drive]] applications, as well as [[rear-wheel drive]] [[automobile|cars]].


The C20XE served as the base for the turbocharged [[C20LET]], which appeared in versions of the Vauxhall Cavalier/Opel Vectra and the Vauxhall/Opel Calibra. The C20LET was identical on the surface, apart from a black plastic plenum/'top hat' shroud with a 'turbo' script. This version features forged, lower compression [[Mahle]] pistons, and offers a 34% increase of power (204 PS) over the C20XE.
The first version arrived in the [[Opel Vectra#Vectra A|Opel Vectra]] / [[Vauxhall Cavalier]] (both codenamed "Vectra-A") and [[Opel Calibra|Opel/Vauxhall Calibra]] in the C25XE form, and was later followed by the X25XE in the [[Opel Omega|Opel/Vauxhall Omega]] and Vectra-B, with the Omega gaining a variant with increased displacement in the form of the '''[[X30XE]]'''.


Some versions of the engine implemented switchable [[Traction Control]] (commonly included in the early Astra GSi models). The inlet had a secondary throttle valve sandwiched underneath the primary throttle body. This is closed by a motor/arm assembly when the traction control ECU senses loss of grip/spin at the wheels. The engine was also equipped with a different Throttle Position Sensor (six pin, as opposed to three), and a different Coolant Temperature Sensor (which was black, as opposed to the normal light blue colour).
This power plant was a modern [[multi-valve|4 valve per cylinder]], quad cam arrangement, with an oil to water [[heat exchanger]] mounted within the V of the [[Cylinder block|engine block]]. The [[cylinder head]]s were constructed from aluminium alloy, and the block from [[cast iron]].


In its last version before production ended, the C20XE came with a new engine management system which included a distributorless ignition system, namely Bosch Motronic 2.8. The last version was called C20LN (Low Noise) and has a stronger engine block. The engines that appeared in the early 90's also swapped the cast metal spark plug cover for a cheaper (and less regarded) plastic version.
An unusual feature of the engine was its 54 degree [[Cylinder (engine)|cylinder]] angle, as opposed to the more conventional 60 degree setup used on many V6 units, this added to the setups' compactness.  


The C20XE evolved into the [[X20XEV]](1994) with {{convert|136|hp|abbr=on}} and taking on the GM Ecotec name and finally it evolved into the [[X20XER]](1999).
A [[Robert Bosch GmbH|Bosch]] [[Motronic]] engine management system is used to control the unit, with full sequential [[fuel injection]], knock control on each bank, [[distributor]]less [[ignition system]] (DIS), and closed loop lambda control.
 
The 20XE has now evolved into a large family of GM 16v engines, one of which is a 2.2L 16v chain driven engine found in many GM brands, including Saab, Pontiac, Saturn, Chevrolet, Oldsmobile. It was borrowed to [[Fiat]] and [[Alfa Romeo]], for the [[Fiat Croma|Croma]] and the [[Alfa Romeo 159|159]] respectively.
 
All of the 2 litre engine of this era share the same cast iron engine block with the exception of the oil return for the turbo on the [[C20LET]].
 
==Origin==
The engine was designed by Dr [[Fritz Indra]], who was head of Advanced Engine Development for Opel in Germany from 1985 to 1989. The engine was originally intended for race application, hence [[Cosworth]]'s involvement.<ref>{{cite web | title = "Interview with Dr Fritz indra" | work = ''www.CalibraWiki.com'' | accessdate = 2008-04-13 | url = http://www.calibrawiki.com/images/d/db/Vauxhall_Calibra_Designer_Interview.pdf}}</ref>
 
=='COSCAST' (Early) and GM (Later) head differences==
The C20XE engine's [[head]]s came in two notable forms. The original versions that appeared for a number of years in the [[Astra GTE]], [[Calibra]] and [[Vauxhall Cavalier]]/[[Opel Vectra]] from 1988 to 1991 were cast by [[Cosworth]]. These are usually more sought after, due to their superior casting qualities, over the GM version which was introduced some time in 1991 (appearing with the [[Astra GSi]]). One of the alleged qualities of the 'COSCAST' head is its inherent resistance to porosity; this was achieved by eliminating the presence of tiny air bubbles during the casting process. The Coscast head can be identified by a 'Coscast' logo which is stamped under the 3rd exhaust port. The GM head was manufactured by Kolben-Schmidt and featured different oil/water galleries, which required a pair of welsch plugs to be pressed in at either end. Incidentally, the presence of welsch plugs proved to be the sole means of identification for a GM manufactured head. A reinforced version of the GM head became available in the later years of the C20XE; however, these reinforcements meant that it had smaller inlet/exhaust canals than the other two.<ref>{{cite web | url = http://www.vauxhall-sport-forum.com/phpBB2/coscast-vs-gm-heads-pics-t309.html | title = Detailed GM & Cosworth difference photos | work = Vauxsport | accessdate = 2008-04-13}}</ref>
 
Since an engine's oil pressure is much higher than its coolant pressure, oil in a porus head has a tendency to gradually seep into the cooling galleries. A typical symptom of a porous head is usually a '[[mayonnaise]]'-like substance in the coolant (residing on the cap). However, symptoms of a porous head have a tendency to vary, depending on the degree of porosity. Many C20XE operators have described the symptom as a curry-like residue or in more severe cases, a thick brown sludge. During the porous head debarcle, GM faced bankruptcy - therefore dealers failed to recall affected models. However, as a result, many businesses now specialise in the repair of porous GM C20XE/LET heads - by either sleeving the affected gallery or by injecting a polymer based substance into the porous region. Typically, the amount of cylinder heads that were reportedly porous remained relatively low.<ref>{{cite web | url = http://www.orsas.com/CarStuff/cav/index.php | title = Porous GM Head Info | work = Scoobler | accessdate = 2008-04-22}}</ref>
 
The early engines used round tooth [[cambelt]]s, the later used square (with a plastic pre-tensioner). There are also subtle differences between the crankshaft, and visible difference in the pattern of the SFi airbox.
 
==Motorsport==
The C20XE has seen extensive use in motorsport. Typical uses for the engine have ranged from hillclimb events, to open wheel racing categories. Despite its age, it remains the powerplant of choice for many [[Formula 3]] teams and has most recently found acclaim in the Australian F3 scene where Tim Macrow, the 2007 Australian F3 champion, drove an Opel-Spiess powered car to claim victory. Tuned by Spiess, an F3 grade C20XE is easily capable of producing {{convert|250|bhp|abbr=on}} in its naturally aspirated form. Many aftermarket tuners have further developed the C20XE for racing purposes. Recently, SBD Motorsport, an aftermarket tuning company based in the UK, developed a C20XE unit with a power output in excess of 290BHP.<ref>{{cite web | url = http://www.sbdev.co.uk/Taper%20Kits/New%202.0L%20Taper%20Kits/2.0L%20TP%20kits%206th%20upgrade/2.0L%20TP%20kit%206th%20upgrade.htm| title = SBD Website | work = ''290+ Taper Throttle Kit'' | accessdate = 2008-05-25}}</ref>  Typically, the SBD built engines have seen use in Westfield and Caterham vehicles competing in various hillclimb events.
The C20XE is currently used by the Chevrolet WTCC (World Touring Car Championship) team and the new Lada WTCC team. The engine is an option in Westfield kitcars.
 
==Technical information==
The breakdown of the engine name<ref>{{cite web | title = "Engine Codes Explained" | work = ''Topbuzz Website'' | year =  2002 | accessdate = 2007-07-05 | url = http://topbuzz.co.uk/info/engine_codes/engine_codes.htm}}</ref> is as follows:
 
*C  - Exhaust Emissions Level: ECE R 83 A
*20 - Displacement: 2 litre
*X  - Compression Ratio Threshold: X = 10.0-11.5:1
*E  - Mixture System: Electronic Fuel Injection
 
The engine produces {{convert|150|bhp|kW PS|0|abbr=on}} at 6,000 rpm, with a low optimum specific fuel consumption of 232 g/kWh which is equivalent to a maximum efficiency of 37 per cent; a better efficiency than some of the diesel engines that were available at the time of its release. The valves are set at 46 degrees and are accompanied by pistons with shallow valve pockets - thereby eliminating the need for a shorter con rod hence, allowing a suitable compression ratio to be achieved. Long spark plugs are used and positioned concentric to the cylinder. Incidentally, the engine has a square bore/stroke and shares piston dimensions with the [[Bugatti Veyron]] (86mm x 86mm).


==Technical data==
{| class="wikitable"
{| class="wikitable"
! '''Engine'''
! '''Engine'''
| '''C20XE'''
| '''X25XE'''
|-
!No Of Cylinders
|4
|-
|-
!Configuration
!configuration
|Inline/Straight
|[[V6 engine|V6]] [[petrol engine]]
|-
|-
!Displacement
!displacement (cc)
|1998 cc (121.88 cu in)
|2498
|-
|-
!Bore (mm)
!bore (mm)
|86.0
|{{auto mm|81.6|3}}
|-
|-
!Stroke (mm)
!stroke (mm)
|86.0
|{{auto mm|79.6|3}}
|-
|-
!Power
!max power kW @rpm
| {{convert|150|bhp|kW PS|1|abbr=on}}/6000 rpm
|{{convert|125|kW|hp}} @ 6000
|-
|-
!Torque
!max torque Nm @rpm
|{{convert|196|Nm|lbft|0|abbr=on}}/4800 rpm
|{{auto Nm|227|0}} @ 3200
|-
|-
!Compression ratio
!compression ratio
|10.8:1
|10.8:1
|-
|-
!Engine management
!engine management
|Bosch Motronic 2.5/Bosch Motronic 2.8
|[[Robert Bosch GmbH|Bosch]] [[Motronic]] M2.8.1 then M2.8.3 in 2000 approx
|-
|-
!Idle speed rpm
!idle speed
|800-900
|450-1030
|-
|-
!Max rpm
!max rpm
|6800
|6600
|-
|-
!Firing order
!firing order
|1-3-4-2
|1-2-3-4-5-6
|}
|}


==List of cars fitted with C20XE==
{| class="wikitable"
{|class="wikitable" width="100%"
! '''Engine'''
!Model
| '''X30XE'''
!Years
!Market
|-
|-
|[[Opel Calibra]] 16V
!configuration
|1989-1994
|[[V6 engine|V6]] [[petrol engine]]
|Europe, Australia
|-
|-
|[[Opel Kadett]] E, GSI/GTE
!displacement (cc)
|1988-1992
| 2960
|Europe - Germany, Ireland
|-
|-
|[[Opel Vectra]] A, GTE
!bore (mm)
|1988-1995
| {{auto mm|86|3}}
|Europe, New Zealand
|-
|-
|[[Opel Astra]] F
!stroke (mm)
|1991 - 1996
| {{auto mm|85|3}}
|Europe, Australia
|-
|-
|[[Vauxhall Calibra]] 16V
!max power kW @rpm
|1989-1994
| {{convert|155|kW|hp}} @ 6000
|UK
|-
|-
|[[Vauxhall Astra]] Mk 2, GTE
!max torque Nm @rpm
|1988-1992
| {{auto Nm|270|0}} @ 3400
|UK
|-
|-
|[[Vauxhall Cavalier]] Mk 3, GSi, SRi
!compression ratio
|1988-1995
| 10.8:1
|UK
|-
|-
|[[Vauxhall Astra]] Mk 3, GSi
!engine management
|1991 - 1994
| [[Robert Bosch GmbH|Bosch]] [[Motronic]] M2.8.1 then M2.8.3 in 2000 approx
|UK
|-
|-
|[[Lada 110]]
!idle speed
|1996 -
| 450-1030
|Europe, Russia
|-
|-
|[[Chevrolet Vectra]] GSi
!max rpm
|1993 - 1996
| 6600
|Brazil
|-
|-
|[[Holden Commodore]]
!firing order
|1988-1991
| 1-2-3-4-5-6
|Australian export to New Zealand, Singapore, sold strictly as the Holden Berlina in those markets
|}
|}
The "X" variant of the engine had the addition of secondary air injection, and EGR to meet later and more stringent emission requirements.
The air injection blew air via a large blower into the [[exhaust manifold]]s to ignite un-burnt fuel in the downpipes during the engine warm up phase, in order to get the [[catalytic converter]]s up to temperature faster.  The EGR setup re-cycled exhaust gases (which are in theory inert to the combustion cycle) in order to reduce the production of NOx.
==History==
Minor changes were made to the unit during its production, including an uprated [[oil pump (internal combustion engine)|oil pump]] around mid 1997, with the addition of larger oilways in the head machining (T-Vents), and modified [[tappet|valve lifters]] to reduce top-end valve noise, at which point the [[timing belt|cam belt]] arrangement also changed with the lower idler moving.
Around 1998, the spin-on metal canister [[filter (oil)|oil filter]] was changed to a disposable paper element.
2000 saw a complete revision of the power plant in order to meet increasing emission requirements, with the 2.5 and 3.0 being replaced by lower compression 2.6 (Y26SE) and 3.2 (Y32SE) units.
These later power plants had a revised [[engine management system]] setup, which utilised quad lambda sensor control, coil per plug ignition system and [[drive by wire]] throttles.  The 3.2 also received a stronger steel [[crankshaft]].  As a result of these changes the EGR and secondary air injection system were removed.


==References==
==References==
{{reflist}}
{{reflist}}


[[Category:GM engines|2.0L]]
[[Category:GM engines|2.5L]]
 
[[el:C20xe]]
[[nl:C20XE]]

Revision as of 15:27, 3 February 2009

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This article needs additional citations for verification. Please help improve this article by adding reliable references. Unsourced material may be challenged and removed. (June 2008)
X25XE
ManufacturerGeneral Motors Europe
TypeV6 petrol engine
PredecessorC25XE
SuccessorY26SE
Bore81.6 mm (3.213 in)
Stroke79.6 mm (3.134 in)
Displacement2.5 L (2498 cc, 152.4 cu in)
Block alloycast iron
Head alloyaluminium alloy
Valvetrain2x DOHC
Fuel typeunleaded petrol
Oil systemwet sump
Cooling systemwater/antifreeze
Power output125 kilowatts (168 hp)
Torque output227 N·m (167 lb·ft)
Compression ratio10.8:1
X30XE
ManufacturerGeneral Motors Europe
TypeV6 petrol engine
SuccessorY32SE
Bore86 mm (3.386 in)
Stroke85 mm (3.346 in)
Displacement3 L (2960 cc, 180.6 cu in)
Block alloycast iron
Head alloyaluminium alloy
Valvetrain2x DOHC
Fuel typeunleaded petrol
Oil systemwet sump
Cooling systemwater/antifreeze
Power output155 kilowatts (208 hp)
Torque output270 N·m (199 lb·ft)
Compression ratio10.8:1

The X25XE is a General Motors Europe (GM) petrol engine. It is a 2498 cc (2.5L) 24 valve, DOHC V6 engine, producing, in standard form 125 kilowatts (168 hp) (170 PS).

The breakdown of the engine name [1] is as follows:

X - Exhaust Emissions Level: 94/12/EC, stage 2
25 - 2.5 Litre displacement
X - Compression Ratio - 10.0-11.5:1
E - Mixture System - Injection

In the early 1990s, GM identified the need for a modern, lightweight and compact power plant to replace its ageing straight-6 engine range. This engine needed to be compact, to allow its use in front-wheel drive applications, as well as rear-wheel drive cars.

The first version arrived in the Opel Vectra / Vauxhall Cavalier (both codenamed "Vectra-A") and Opel/Vauxhall Calibra in the C25XE form, and was later followed by the X25XE in the Opel/Vauxhall Omega and Vectra-B, with the Omega gaining a variant with increased displacement in the form of the X30XE.

This power plant was a modern 4 valve per cylinder, quad cam arrangement, with an oil to water heat exchanger mounted within the V of the engine block. The cylinder heads were constructed from aluminium alloy, and the block from cast iron.

An unusual feature of the engine was its 54 degree cylinder angle, as opposed to the more conventional 60 degree setup used on many V6 units, this added to the setups' compactness.

A Bosch Motronic engine management system is used to control the unit, with full sequential fuel injection, knock control on each bank, distributorless ignition system (DIS), and closed loop lambda control.

Technical data

Engine X25XE
configuration V6 petrol engine
displacement (cc) 2498
bore (mm) 81.6 mm (3.213 in)
stroke (mm) 79.6 mm (3.134 in)
max power kW @rpm 125 kilowatts (168 hp) @ 6000
max torque Nm @rpm 227 N·m (167 lb·ft) @ 3200
compression ratio 10.8:1
engine management Bosch Motronic M2.8.1 then M2.8.3 in 2000 approx
idle speed 450-1030
max rpm 6600
firing order 1-2-3-4-5-6
Engine X30XE
configuration V6 petrol engine
displacement (cc) 2960
bore (mm) 86 mm (3.386 in)
stroke (mm) 85 mm (3.346 in)
max power kW @rpm 155 kilowatts (208 hp) @ 6000
max torque Nm @rpm 270 N·m (199 lb·ft) @ 3400
compression ratio 10.8:1
engine management Bosch Motronic M2.8.1 then M2.8.3 in 2000 approx
idle speed 450-1030
max rpm 6600
firing order 1-2-3-4-5-6

The "X" variant of the engine had the addition of secondary air injection, and EGR to meet later and more stringent emission requirements.

The air injection blew air via a large blower into the exhaust manifolds to ignite un-burnt fuel in the downpipes during the engine warm up phase, in order to get the catalytic converters up to temperature faster. The EGR setup re-cycled exhaust gases (which are in theory inert to the combustion cycle) in order to reduce the production of NOx.

History

Minor changes were made to the unit during its production, including an uprated oil pump around mid 1997, with the addition of larger oilways in the head machining (T-Vents), and modified valve lifters to reduce top-end valve noise, at which point the cam belt arrangement also changed with the lower idler moving.

Around 1998, the spin-on metal canister oil filter was changed to a disposable paper element.

2000 saw a complete revision of the power plant in order to meet increasing emission requirements, with the 2.5 and 3.0 being replaced by lower compression 2.6 (Y26SE) and 3.2 (Y32SE) units.

These later power plants had a revised engine management system setup, which utilised quad lambda sensor control, coil per plug ignition system and drive by wire throttles. The 3.2 also received a stronger steel crankshaft. As a result of these changes the EGR and secondary air injection system were removed.

References

  1. ↑ Topbuzz, "Engine Codes Explained", Topbuzz Website, 2002. Accessed 9 Dec 2006 [1]
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