N52 oil pan design for Z4 engine arm based swap

[Dwes]

Am here for all the little Details ..!!!perfect

[Striker01]

Here are a couple shots of the pan test fitted on the engine. Lots of clearance except for my tie rod boots, maybe 1/4" there. Great ground clearance, I don't have any pictures but I'm sure its higher the M20 pan was.




Then on to what I think is the most difficult part of the pan assembly, the oil pickup. So far everything has been done with basic tools except the welding. For the pickup you really need someone with a lathe unless you could research and find an O-ring fit tube that will fit the N52 oil pump.

I used 1 1/4 x4" of aluminum rod and 24" of 3/4ID 7/8OD stainless tubing; 12" would be more than enough. I also ordered the stainless pickup brace, that Hoveringuy designed, from sendcutsend. The pickup is one I ordered for a VW Jetta, I'm pretty sure he designed the baffle around that one. It's compact and the tubing has a 7/8' diameter, I cut it off right below the bend. Sorry I forgot to get a picture of it.

Here is the brace he drew up in CAD. The bonus is that the extra you cut off is just enough to cap the two 3/4" pieces of tubing required for this way of doing it. I'm copying hoveringuy's setup for all this, its working great for him and his car gets driven much harder than mine ever will.



I used a local guy for the lathe work, it cost me $100 for 1.5 hours of his time to machine the pickup. I took him the original pickup for dimensions and he turned the aluminum rod down to match then press fit the stainless tube inside with a bit of loctite for good measure. I meant to order stainless rod and just weld the tubing onto it but either I ordered it wrong or I got shipped the wrong stuff. That was a couple months ago and I don't remember where I ordered it from to check who messed up. Aluminum is way easier to work with so this probably worked out better and after watching how much it took to press in the rod I'm not worried about it leaking.

Here is what I had when he finished.

[Striker01]

Next I needed to notch the tubing to get around the part of the oil pump that sticks out towards the back, under the pickup hole. If you notch about half the diameter of the tubing it will clear. I tried to use a 7/8 hole saw but without a drill press and the part clamped down it was a nightmare, I got the pickup piece done that way but did the second one with a band saw and dremel. Here is how they turned out.




Next I tacked them together for a test fit.



And the test fit.



It does angle towards the front slightly, that was to keep the pickup from hitting the back divider on the baffle. That's what the blue tape is representing. Ideally I would've notched it closer to the oil pump but with a press fit I wanted plenty of surface area between the stainless and aluminum, just to be safe.

[Striker01]

Once I was pretty sure it would work I trimmed both pieces of tubing close to flush and used the extra from the brace for the caps.




The step I didn't get pictures of was measuring from the bottom of the pan to the pickup tube. Once I had that distance set I put a single tack on the jetta pickup to flush it with the bottom of the pan. Then a couple more tacks on the Jetta pickup and off to my brother's for final welding.



All sealed up and ready for the brace piece.

[Striker01]

Test fit after welding just to make sure it didn't move to much.



Baffle partially slid in to make sure the pickup is in the right spot before welding on the brace.



The brace was pretty simple. I had to sand the tubing slightly to get it to slide through the hole but fit great otherwise. Pulled the pan out, cut a short piece of tubing, snugged up the bolts and tacked it in place. I'll get it final welded when we seal up the pan.

[Striker01]

Oil pickup done, next step is to figure out the dipstick and M20 oil level sender. I want to keep the oil level light working on the overhead panel, only reason I'm adding it to this pan.

Marked where I think it will work best, I just needed to make sure it wouldn't interfere with the baffle sections. Cut a hole and weld the flange on.



Fully welded and realized we got a little too much heat into it. Don't think this will work, good thing I have extras.



A little work on the belt sander and start over.


This time we welded it slower and with the sensor clamped in place, minus the o-ring.

[Striker01]

Fully welded and flat. The first time we welded it on the inside as well, decided to skip that this time to try and keep it flat. It warped the side of the pan pretty good so I hammered it back out the best I could.



No on to the dipstick, just trying to copy hoveringuy's setup here as well. Mocked it up with the last piece of the pan held in place with magnets. My goal was to get the full indention on the dipstick about 1/4" below the top of the wing.




Got a little crazy trying to cut the hole so I decided to MIG weld the inside, had some pretty good gaps to fill.



TIGed the topside and sanded the inside of the opening to keep from tearing the o-ring.



Media blasted the pan and this last piece one before welding it up. Decided to cut the top of the baffle out, where I will be able to get to after the pan is sealed. I wanted to be able to get the flaps in and trim for the pickup after having the pan powder coated. I later decided to paint it instead, so I could've trimmed for the pickup clearance before sealing up the pan and not had the hole in the top.

[Striker01]

A little more trimming on the baffle for the dipstick and level sender. Tacked the baffle together and started welding the last piece of the pan on.



The last corner that had to be figured out, plenty of extra metal from the pan pieces in the SCS plans.



Rest of the final piece welded in place, fit right together.



I also added the connector holder for the level sender.

[Striker01]

After welding I decided to acid wash the pan before paint. In hindsight, I'm not sure that was a good idea. The inside of the pan flash rusted in the time it took me to get it painted and oil in it. The oil should keep it from rusting any more but I still don't like the idea of rust in there. Time will tell I guess. I did have to trim the hole for the pickup to get it to clear when installing the pan, that complete I tacked the top baffle piece in place, the thin stainless warped a little on me but I don't think it will cause an issue.

Flaps installed, ready to seal up.


I had to add a vent hole in the dipstick tube. After I filled the pan, the dipstick was still dry. The dipstick tube that slides into this bung has a hole so I went ahead and drilled one in this piece as well. I didn't like doing it after the pan was finished but I used a magnet while drilling to get most of the shavings out, hopefully the magnet on the drain plug will capture the rest.



I drilled a larger hole in the dipstick tube, just in case I have to rotate it slightly when I get everything set.

[Striker01]

Here is 5.5 quarts, It's just at the bottom of the full indention on the dipstick. It's amazing how much you can tilt this pan around the the pickup area just stays full.

Any thoughts on how full I can get the oil, would flush with the baffle top be ok? Could probably hold 6 quarts if I can go that high.



I forgot to add that to test for leaks I bought some aluminum tape and taped up the bedplate with about 4 layers, on the pan mating side. Installed a new gasket, dry, and bolted the pan down. I could only get a few PSI before the tape would tear on sharp edges but it was enough to soap and water all the seams on the pan and see that the tape stayed ballooned until I opened the valve and relieved pressure.

[hoveringuy]

Huh, never considered needing a vent there. I just figured that removing the dip itself makes a big vent on top...

My big question when I removed the pan after 2 years was how much surface corrosion or flash rust I would see, because it's steel, right? There was none. Zero. It looked shiny and brand-new everywhere.

I stressed over corrosion from the weld area inside my fuel tank as well and did the same thing and it flash rusted almost immediately, and I needed to soak it in rust dissolve to clear it up. Any paint would be subject to peeling and a bigger worry than corrosion would ever be. Paint flakes would clog the pickup!

You're plenty good at 5.5 qts. Like you've demonstrated, no amount of braking or cornering will ever give you the oil light.

Looking good!

[Striker01]

Huh, never considered needing a vent there. I just figured that removing the dip itself makes a big vent on top...

My big question when I removed the pan after 2 years was how much surface corrosion or flash rust I would see, because it's steel, right? There was none. Zero. It looked shiny and brand-new everywhere.

I stressed over corrosion from the weld area inside my fuel tank as well and did the same thing and it flash rusted almost immediately, and I needed to soak it in rust dissolve to clear it up. Any paint would be subject to peeling and a bigger worry than corrosion would ever be. Paint flakes would clog the pickup!

You're plenty good at 5.5 qts. Like you've demonstrated, no amount of braking or cornering will ever give you the oil light.

Looking good!

It did fill the dipstick tube when I pulled the dipstick out to see where the level was, just figured a vent hole would help. Thanks for the advice and sharing all the files with me. Can't wait to get the engine all back together and start figuring out the wiring.

[projectJTv4]

Imported hoveringuy's .DXF files of the 2.0 version into SolidWorks for funsies.

Striker01 do you happen to have dimensions for the oil dipstick and/or level sensor you used?

[hoveringuy]

projectJTv4 Damn, you make it look all professional!

Here is some more detail on the dipstick. It's two pieces of tubing where the OD of one is the ID of the other, 3/4". It's not like the movies where they just slide together, I heated the outer one up with a torch and then it (barely) slid over with some tapping. Once it cooled they were fused. The difference in length is 8mm. Overall length is 3.5". A stock M50 dipstick tube (NOT the one that includes oil drainback!) slides right in. (I chamfered the very top to make sliding the O-ring in easier)

I think the pan tube is angled out just a hair, but bending the dipstick tube for alignment if it's a little off would be easy.

I think I even used the stock E30 dipstick!

[projectJTv4]

So it would look something like this, with the bottom flush. The dipstick tube seals on the 0.75 diameter and sits on the inner tube.



As an alternative for machining, quickly looking, McMaster has Low Carbon Steel 0.875" OD x 0.635" ID, a slightly larger ID by 0.015".