Finally, the oiling system - an integrated dry-sump in Porsche speak, disparagingly called a wet-sump by almost everyone else, but actually somewhere in-between.
In it's stock form the integrated dry-sump tank is formed from a plastic baffle that sits in the centre of the sump, and whilst the engine is in operation the oil is returned to this internal tank. Sadly, the tank isn't exactly oil-tight, and under heavy G the oil can escape into the rest of the sump. This is largely resolved by fitting the X51 sump which has an aluminium baffle/tank with rubber seals that fit tightly against the internal walls of the sump and do a much better job of keeping the internal tank full under G. This just left the issue with the heads - or, rather, the right hand head (as you look at the car from behind). To save money Porsche used the same casting for both heads, so the drive end of the cams is at the back on the right, and at the front on the left. Each head has an oil scavenge pump that returns oil to the central tank/sump, and under normal conditions this works fine.
However, under heavy braking, and especially if the car is turning left, oil pools in the front of the right hand head as the scavenge pump is at the back, and for that brief period is sucking air. Porsche resolved this by fitting a dual stage scavenge pump to this head that scavenges the front of the head via a port on the cam cover, to which it is connected via external hard-line (the iconic X51 towel-rail). So - buy the dual stage pump and problem solved, right? Sadly not - the currently available dual stage pump spins backwards, which we considered to be sub-optimal. So we made our own:
Finally, the oiling system - an integrated dry-sump in Porsche speak, disparagingly called a wet-sump by almost everyone else, but actually somewhere in-between.
In it's stock form the integrated dry-sump tank is formed from a plastic baffle that sits in the centre of the sump, and whilst the engine is in operation the oil is returned to this internal tank. Sadly, the tank isn't exactly oil-tight, and under heavy G the oil can escape into the rest of the sump. This is largely resolved by fitting the X51 sump which has an aluminium baffle/tank with rubber seals that fit tightly against the internal walls of the sump and do a much better job of keeping the internal tank full under G. This just left the issue with the heads - or, rather, the right hand head (as you look at the car from behind). To save money Porsche used the same casting for both heads, so the drive end of the cams is at the back on the right, and at the front on the left. Each head has an oil scavenge pump that returns oil to the central tank/sump, and under normal conditions this works fine.
However, under heavy braking, and especially if the car is turning left, oil pools in the front of the right hand head as the scavenge pump is at the back, and for that brief period is sucking air. Porsche resolved this by fitting a dual stage scavenge pump to this head that scavenges the front of the head via a port on the cam cover, to which it is connected via external hard-line (the iconic X51 towel-rail). So - buy the dual stage pump and problem solved, right? Sadly not - the currently available dual stage pump spins backwards, which we considered to be sub-optimal. So we made our own:
Leading to: