Sump and Strainer Plate. How to Rebuild Your Air-Cooled Porsche.

Installing a sump plate

On this lesson we cover the sump and strainer plate. Even though the case has been closed and honed, the sump plate should have enough wiggle room to still fit.

Video lesson on the sump plate installation

Sump on a Magnesium engine case

On this 1969 911T engine, we are working with a magnesium engine case. Check out, Saving your Mag Case, for a look at the work involved in prepping a case for a build.

On this engine we did not have the sump re-faced. The corrosion is light but may be enough for an oil weep. Any heavy corrosion should be dressed when the case is at the machine shop. They will need to have all the studs removed and the case needs to be together for the machine work.

Very corroded sump on a magnesium case
Very corroded sump on a magnesium case. This case was a loss!
Machined sump surface
Machined sump surface

Sump and Strainer plate installation

Because of the light corrosion on this engine case, we are going to modify how we install the sump and strainer plate. A gasket goes on first, and on the surface that attaches to the case, we apply a small amount of Loctite 475.

Next, the strainer plate goes on. Check that the holes and the mesh are all in good shape. You can bend the strainer plate very easily, so be gentle when re-shaping.

Do not use ant sealant on this plate. There will be problems in general service if the fragile plate is stuck in place! So dry and clean.

After the strainer plate, there is the second gasket. Keep it clean and dry on the face that goes against the strainer plate. Because there is some light corrosion on the sump plate we will use another small serving of 475.

We had the sump plate powder coated, but you can still feel and see the light corrosion. If your parts are like-new, do not use any sealant in this operation.

The drain plug only has one correct placement. We see many engines with the drain plug in the wrong place. The drain plug needs to be beside the oil pump pickup. Not on the pickup and not in front of the pick-up.

Torque Settings

The original configuration for the sump plate is a flat washer a wave washer and a nut. We like to use Nylock nuts and they only require a flat washer. A Nylock is one-time use and if you want to remove the sump again, you will have to replace all the nuts.

The 6mm Nylocks will torque at 6 Newton Meters

The 15mm Sump plug thread should be lightly oiled and the aluminum crush washer added. This washer conforms as it is crushed in place, and is also a one time use.

The sump plug will torque at 42 Newton Meters.

Up Next in your Air-Cooled Engine build

We will work on the oil system. The breather plate, oil fittings, and the oil thermostat.

If you missed any part of this build, check out the 911 Engine page.


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