Do you need the oil strainers inside the crankcase?

[Elferhelfer]

Hello together,
I would like to know, if you really need the oil strainers during an engine rebuild?

I opened an engine case for rebuild and the left and rear oil strainer (901.101.035.01 ) were missing. Could you skip them during an engine rebuild?

It would be great, if I could get some feedback from the specialists…

[edmayo]

I believe the strainers were meant to de-aerate the oil. As the oil passed thru them it would break up air bubbles. Later, due to more internal stiffening ribs, it wasn't possible to install the screens. I think also as oil science improved the oil was less likely to froth up anyway. Don't take this as gospel,,,,,just theories of mine!

[304065]

They weren't used in later cars. . . I left them out when I rebuilt '065's engine.

[gled49]

Lots of mechanics removed them, believing they held the oil up and into the crankshaft. Removing them allows the oil to drain more quickly and move away from the crank, reducing foaming and improving windage. Gordon

[66S]

So Porsche installed them to reduce aeration (foaming?) but mechanics removed them to reduce foaming? I think me hanics removed them because the plastic fell apart. Id trust Porsche engineering over mechanics theories. I will install some nos ones in my early motors. There is another screen in the oil tank, at least the early one I took apart.

[SIMI BOB]

Last year I asked Henry at Supertec if I should install the screens, and he said no. Apparently the plastic around the edges comes apart and that's not a good thing.
Bob B

[frankc]

The 2.4 I'm rebuilding still had the windage screens in it. Given that the screens are original (case appears never to have been opened) and replacements are NLA, I think putting them back in poses too much risk of the 40+ year old plastic frame crumbling, especially when there is no risk of damage by leaving them out.

From what I've read, the benefit of the screens is to reduce parasitic HP loss at high RPMs due to the crank moving through the oil spray/foam, but I suspect the impact is much larger on a wet-sump engine than on our dry-sumps.

[Will 1967]

Completely from my memory but I'm pretty sure these were all metal in aluminium cases so no plastic parts (I removed some from couple of cases months ago), I'm most likely installing mine back on.

[Elferhelfer]

Thanks alot for your feedback. Now it's a little bit clearer for. Will rebuild the engine without them....

Last year I opened a 1970 E Sportomatic engine and inside I found the version with plastic around....

[letsrollbabe]

I have a pair of screens in excellent unbroken condition that came out of a discarded 72 case if someone wants them...send a PM.