Silber’s 2002 Boxster S Engine Build

[ike84]

I havent seen that build thread before. Martin refers to building his own scavenge pump but never elaborated on how. I'll have to go through that thread to see if dammit explained the process.

The math here is pretty straightforward though, and plainly explains why that pump (or lack thereof) is the true Achilles heel of the oiling issue.

The main oil pump, which is driven from the crank, moves 20+L of oil per minute at high rpms (which is obviously where this car needs to live to compete in motorsports events). The problem is that the scavenger pumps are offset, with (on the 986) bank 1 being toward the front and bank 2 being toward the rear. On long sweepers at breakneck speeds, the oil will pool toward the rear of the engine. Do this around a left hand turn and the oil pools into the bank 2 scavenger pump. Do this around a right hand turn and the oil pools into a corner. Sustain the turn for 45-60 seconds and the main pump has moved the entire volume of oil through the system twice, with a huge amount of it being stuck in the rear corner of bank 1.

This is why acchsumps, deep pans, and improved baffles aren't the answer (although the last certainly does help keep the oil near the pickup tube without question). We're not talking about needing an extra quart or two to get through that turn, were talking the whole damn oil capacity. The real **************** of this that most aftermarket oil pumps, even the best like turbowerx, don't move over than a gallon per minute. You have to have crank driven pumps to move higher volumes (I don't know what the scavenger pump capacity is, I'd love it if someone could chime in on that). 1gpm may be enough to fix the problem though, but I've not ever seen anyone doument that approach.


Btw, Porsche knew this before they distributed the M96,. That's why the owners manual says to not use racing tires. They're not trying to cover their butts and stop people from racing, they knew the motor wasn't up to the task before it even left Stuttgart. How's that for a legacy of motorsports excellence?

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