b0bby
Member
Registered: 16th Dec 03
Location: Stockport, Greater Manchester
User status: Offline
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Hey there,
whats the physical difference between the earlier corsa engines.... (mine 2001)
and the new twinports.. i was hopeing to do a conversion to a twinport.
So hopeing theres nothing majorly different?
(just read another post... from what i read, theres nothing different as far as pipes, fuel lines etc... just something in the engine to recirculate something.... LOL
Rob
[Edited on 25-09-2005 by b0bby]
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fragpot
Member
Registered: 29th Feb 04
Location: Linlithgow, West Lothian
User status: Offline
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Twinport system
The Twinport system, already in use in the Z 16 XEP DOHC-I petrol engine now also features on the two new members of the 2nd generation DOHC-0 petrol engine series, the Z 10 XEP and Z 14 XEP, albeit in modified form.
Advantages of Twinport
Greater movement of the charge
Combustion stabilisation
Increase in exhaust gas recirculation rate
Reduction in throttle losses
Reduction in fuel consumption
Special features
When the Twinport system is activated (part load), combustion is stabilised because of the increased movement of the charge. Thanks to more efficient combustion, both throttle and wall heat losses can be overcompensated for by the high EGR rates, resulting in a reduction in fuel consumption.
Advanced injection of the fuel onto the closed inlet valve
Stratification of the charge with a richer mixture at the point of ignition at the spark plug.
Inlet manifold with Twinport system
The structure of the inlet manifold is in principle the same for both the Z 10 XEP and Z 14 XEP engines. They only differ in length, which is tailored to the respective engine version (3-cylinder or 4-cylinder).
A vacuum unit actuates the Twinport system; the unit uses a shared actuation rod to close and open the flaps in the inlet ports.
1
Inlet manifold - Z 14 XEP
3
Reverse-transfer lever
2
Vacuum unit
4
Actuation rod
Control valves - Twinport system
At idle when the vehicle speed signal = 0, the control flaps of the Twinport system are closed and the system is active.
As soon as the vehicle drives away, and a driving speed signal is thus present, the control valves are opened or closed, depending on the operating point (load, engine speed).
The engine control unit gives a command to the vacuum unit which in turn closes or opens the control flaps via the actuation rod.
• Service:
So as not to diagnose the Twinport system incorrectly when checking it, the following should be taken into account:
At idle and when the driving speed signal = 0, is when the vehicle is stationary, the control flaps must be closed, the actuation rod is withdrawn and there is a vacuum at the vacuum unit diaphragm.
When the vehicle is being started, the control flaps are opened and after a short while (a few seconds) the control flaps are closed when the vehicle is at idle and the driving speed signal = 0.
Control flaps opened
Control flaps closed
1. Reverse-transfer lever
2. Connection for engine wiring harness
3. Vacuum hose
4. Vacuum tank (engine control unit removed)
The following diagram shows the Twinport system in both activated and deactivated states.
Twinport system inactive with opened control flap
Twinport system active with closed control flap
1. Control flap
Twinport sensor
The Twinport sensor incorporated into the inlet manifold records whether the Twinport flaps are open or closed and sends this message to the engine control unit.
There, the signal of the Twinport sensor is compared with the specified setpoint position.
1. Inlet manifold
2. Twinport sensor
3. Test connection - fuel pressure
• Service:
The control flaps cannot be exchanged or replaced.
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seanreay1986
Member
Registered: 30th Jul 04
Location: Washington, Tyne and Wear
User status: Offline
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is there any power difference in say the 1.2 16v and the 1.2 16v twinport?
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fragpot
Member
Registered: 29th Feb 04
Location: Linlithgow, West Lothian
User status: Offline
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With an innovative variable intake control system called "Twinport", Opel plans to reduce the fuel consumption of small gasoline engines (up to a maximum size of 1.6 liters) by as much as six percent. The smart solution employs a variable intake manifold in combination with a high rate of exhaust gas recirculation. The "Twinport" technology works in conjunction with engines with four valves per cylinder, a requirement fulfilled by Opel's complete ECOTEC range.
"Twinport" controls the supply of the fuel-air mixture to the cylinders according to the engine's actual needs. At part load, one of the two intake ports leading into the cylinder is throttled. This causes an intensive swirl effect to develop as the mixture enters the cylinder, which in turn makes the engine more economical when operating with a high proportion of recirculated exhaust gas. At full load, on the other hand, the throttling device is opened, the cylinder receives a greater charge of mixture and full power is developed. By adapting the swirl movement of the incoming charge to suit engine operating conditions, maximum fuel economy is always achieved.
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fragpot
Member
Registered: 29th Feb 04
Location: Linlithgow, West Lothian
User status: Offline
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1bhp difference, but 30% better mpg. Thats all I know.
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b0bby
Member
Registered: 16th Dec 03
Location: Stockport, Greater Manchester
User status: Offline
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lol cheers dude,
hanes havnt cover twinport yet 
so ill just have to hope the garage know its stuff,
[Edited on 25-09-2005 by b0bby]
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