Our V8-powered Nissan 350Z has been too quiet lately. Sure, it’s still loud when it’s running–really, really loud–but after two back-to-back podiums in NASA’s TTU class, it hasn’t been running much.
[Surprise podium finish for our 350Z’s competition debut]
Instead, it’s been parked in the back corner of the shop, hooked to a battery tender with a tank full of fuel …
At 1G of cornering an engine runs as if rotated 45 degrees, which puts the outboard bank 'horizontal' for a 90 degree engine. At 1.2G the outboard bank is effectively 5 degrees inverted, and it keeps going from there. As I understand it for the LS, oil in the heads drains back through the lifter galleys, which would be at the effective 'top' for the outboard cylinder head cavity. If that's the case, the outboard bank would have to fill with oil before any could start returning to the sump. Which seems like a pretty obvious low oil pressure culprit. Which has long made me wonder, not only why aren't more people adding external gravity drains off the heads, but why is it not even part of the oil starvation conversation? It should be rather cheap and easy to do if it works. Am I misunderstanding something obvious about how the oil drains from the LS heads, is there a bigger obvious problem with the engine that means this doesn't make a difference, or is a simple solution actually being completely overlooked by an uncomfortably large portion of the community?
Will you need to create a firewall around the new sump in the cabin?
In reply to Driven5 :
Difficulty: As you go up the ladder in pushrod engine stress-testing, you like to run the valve cover area "flooded" so the valve springs stay immersed in oil. They can get really, really hot.
So it may not be the outside head that has insufficient drainback, but the inside head that is starved of oil.
Either way its bad 
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