Is it possible for the motor to be 180 degrees out..?
#16
Chronic Tool Dropper
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Joined: Oct 2001
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From: Bend, Oregon
Closing the loop on this:
The injectors in the car are "batch fired", where all the nozzles are activated at the same time. "Modern" cars are more likely to have sequential injection, where the nozzle is opened just as the intake valve(s) underneath it open. In our batch-injection cars, fuel has a small chance of spraying into an open intake port on any given engine rotation. The rest of the time, the fuel ends up condensing on the walls of the intake and inlet port. It then gets to evaporate into the air flowing through the port when the intake valve(s) actually open. To maintain sufficient fuel content to support proper combustion, a little extra fuel must be added. The problem is much more acute when the engine and intake are cold. Regardless, we have what we have as far as the batch-fired injection.
There are some aftermarket injection systems that support sequential injection, and you can get better higher-capacity nozzles to go with them since they also support more precise opening times. At some point there will be a plug-and-play option that uses a new engine wiring harness and a few more sensors. The installed costs of one of those systems can easily exceed the prices of the used-car market value of many 928 examples. For those who treasure originality, the differences in performance and fuel economy won't appeal enough to make an injection system upgrade desirable.
The injectors in the car are "batch fired", where all the nozzles are activated at the same time. "Modern" cars are more likely to have sequential injection, where the nozzle is opened just as the intake valve(s) underneath it open. In our batch-injection cars, fuel has a small chance of spraying into an open intake port on any given engine rotation. The rest of the time, the fuel ends up condensing on the walls of the intake and inlet port. It then gets to evaporate into the air flowing through the port when the intake valve(s) actually open. To maintain sufficient fuel content to support proper combustion, a little extra fuel must be added. The problem is much more acute when the engine and intake are cold. Regardless, we have what we have as far as the batch-fired injection.
There are some aftermarket injection systems that support sequential injection, and you can get better higher-capacity nozzles to go with them since they also support more precise opening times. At some point there will be a plug-and-play option that uses a new engine wiring harness and a few more sensors. The installed costs of one of those systems can easily exceed the prices of the used-car market value of many 928 examples. For those who treasure originality, the differences in performance and fuel economy won't appeal enough to make an injection system upgrade desirable.
#17
Got it. Thanks. That's f*ing crazy; it sounds like a more complex throttle-body injection.
#18
The issue has nothing to do with 180 crank degrees- the issue is whether your distributor can be mounted 180 camshaft degrees out of synch. As I stated in an earlier post I have no idea if this is possible on a 928 unit so my expectation is that some kind soul will confirm whether this is possible or not. For sure it is nothing to do with fuel injection.
#19
The issue has nothing to do with 180 crank degrees- the issue is whether your distributor can be mounted 180 camshaft degrees out of synch. As I stated in an earlier post I have no idea if this is possible on a 928 unit so my expectation is that some kind soul will confirm whether this is possible or not. For sure it is nothing to do with fuel injection.
Yes, it is possible to set the distributor 180° out in a 16V engine.
#20
If it is a 32V motor kitted with EZF then not possible unless one deliberately reassigned the leads on the two distributors and I think we can safely dismiss that possibility.
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Kiln_Red (11-21-2019)
#21