Quote:
Originally Posted by jaykay
It looks like the 996 head gasket has some kind of flow control orifice function where the 987 does not. One hole is really small. Sooo if they are the same blocks then this would make a difference in what heat transfer occurs via the coolant yes?? Both are putting out the same power; same oiling system; same torque; same water pump.I am not sure what advantages 996 rad distance would give...got to think about that
Are there Cayman guys that gave swapped in the 996 head gaskets? Are there differences in the heads particularly the coolant passages?
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Yes, the hole differences are for coolant flow control. Cyl 6 is the hottest, since it is furthest away from the WP, so on the 996 HG, 6 has the biggest hole for extra cooling. 996 HG are not interchangeable left to right banks. For the 997, Porsche decided to save a couple of bucks and made the HG interchangeable, but to do so, had to equalise the coolant flow orifices. According to Hartech, the refised HG is why Caymans experience left bank cylinder failures.