Porsche 911 UK Enthusiasts Online Community Discussion Forum GB

Welcome to the @Porsche911UK website. Register a free account today to become a member! Sign up is quick and easy, then you can view, participate in topics and posts across the site that covers all things Porsche.

Already registered and looking to recovery your account, select 'login in' and then the 'forget your password' option.

Metzger turbo scavenge pump power

Jay Are

Trainee
Joined
4 Jul 2015
Messages
99
:D evening all.

Do we know anyone who's likely to know what sort of pressure/performance the dual pump turbo sump scavenge pumps run on the 996 turbo engine. I've increased the drain lines on the turbo's to over 100cm each. Will the pump still cope provided the drain line is pretty much flat or are we looking at a lift pump for the extra load??

Odd question I know. Just another in a long line of unknowns...

Any aficionados on here with Metzger engineering/design/race knowledge??

Am trying to avoid having to resort to testing this - with a bucket - under a running car - on axle stands...

:? :?:
 
Scavenge pumps don't operate at any appreciable pressure, their job is to shift the oil back to the tank. If the lines are flat, there should be no real difference in performance, but you may need a whisker more oil in the system to allow for the longer line volumes.

In days of old, we used to run the dry sump tank in the boot of RS1800 Escorts, with the pumps up front on the engine. These would work fine even with monograde Castrol R40 in the tank, though the pressure pump could be a swine to prime after a rebuild. The solution was to jack the rear of the car up, heat the oil, then apply an airline to the tank breather - this was the only way to make it pick the oil up. Once it had been running it was no problem.

The scavenge pumps were not an issue at all, as they move a mix of air and oil back to the tank.
 
Cheers dude.

I don't suppose pressure is going to be an issue in that engine; it's already blown oil upstream against the exhaust flow through all the oil seals in the turbo when I tried to run the drains up over the heads.

Not convinced the internal scavenge is going to have the guts a stand alone pump would have but we can test it. I can open the sumps up and see if they are filling up or just keep an eye out for the blue smoke I guess...

Cheers Mike

Onward but not upward

:thumb:
 
No problem Fella :thumb:

Will the oil tank still be mounted well above the pressure pump? The design of the standard system and installation looks very good to me, though I've not studied it in detail.

Are you still using the Mezger oil tank? Oil tanks need to be very well thought out, make sure you are able to accurately log oil pressure when testing the car, any drops in pressure can be surge within the tank, or a poor tank design not separating the air from the oil well enough. To give you an idea, we commissioned a super-large dyno oil tank which holds well over 10 litres, but despite it being around a metre tall, the thing can still end up with aerated oil at the feed line when used with mega high revving engines. There are weirs and all manner of anti aeration plates inside but it can still froth the oil. If you can run the stock tank with the installation, then best to do so.

There may be some issues with oil scavenge pick up due to the about-face installation, especially under the extremes of hard acceleration and braking. Be careful....

Good luck!
 

New Threads

Forum statistics

Threads
124,546
Messages
1,441,394
Members
48,961
Latest member
gpc
Back
Top