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Posted by: worn Aug 17 2019, 08:08 PM

So, the 911 motor died in montana, the six conversion was considering jettisoning the tranny, and on the lift is the four cylinder 914. For a brief time i figured the fracking had paid off, but now I have to admit major problems with oil leaks.
Most of the trouble is probably from the oil pump gaskets, Melling. Along with oil filter console leaks.
I also want to replace the case bolt sealing nuts with new ones. I cannot find them though. All that i can find are 12 mm nuts for type 1-3 engines. Have they really stopped making the sealing nuts? They look like nyloc nuts with rubber in place of nylon.
Thanks folks.
Warren

Posted by: 914Sixer Aug 18 2019, 01:33 PM

I have bags of the 12m nylock nuts. Did you check with Porsche or VW dealer. Picture is of 12 x 1.75 mm

Attached image(s)

Posted by: Superhawk996 Aug 18 2019, 02:24 PM

Note, the leakage isn't likely to come past the Nylock insert.

Where they do leak is from between the washer and the case, between the washer topside and the nut. I put down a little Permatex between the case and the washer and a dab of YamaBond between the washer topside and the nut on final assembly.

This area isn't under pressure if the PCV system is working properly. More of a weep risk than an outright leak.

Posted by: worn Aug 18 2019, 05:19 PM

QUOTE(Superhawk996 @ Aug 18 2019, 12:24 PM)

Note, the leakage isn't likely to come past the Nylock insert.

Where they do leak is from between the washer and the case, between the washer topside and the nut. I put down a little Permatex between the case and the washer and a dab of YamaBond between the washer topside and the nut on final assembly.

This area isn't under pressure if the PCV system is working properly. More of a weep risk than an outright leak.

I thought that the bolts were made to run through oil galleries in the case, and therefore subject to around 3 bar of pressure. I agree that this isnt a big worry area, but am surprised i cannot find the nuts. Perhaps the nyloc nuts will do the same thing as the rubber sealing nuts.
Thanks

Posted by: Superhawk996 Aug 18 2019, 05:29 PM

As far as I can tell from looking at my split cases, the galley comes in above or below the main bolt bores and doesn't intersect.

I didn't run a borescope though them but I can't see an intersection looking into them.

That would be silly to have 30-60 psi of oil pressure sitting behind those washers.

Take a look at yours, but, there is no way for the oil to get to or past the nylock portion without first leaking around the washer and the bolt shaft. I don't remember ever seeing rubber in any of these nuts, Only brittle old nylock material (red). Somebody tell me if I'm off my rocker.

There are anti-vibration clips that go on these long bolts at the middle of the case split but again, not for sealing. They prevent the unsupported bolt span from resonating and loosening.

Posted by: worn Aug 18 2019, 08:03 PM

QUOTE(Superhawk996 @ Aug 18 2019, 03:29 PM)

As far as I can tell from looking at my split cases, the galley comes in above or below the main bolt bores and doesn't intersect.

I didn't run a borescope though them but I can't see an intersection looking into them.

That would be silly to have 30-60 psi of oil pressure sitting behind those washers.

Take a look at yours, but, there is no way for the oil to get to or past the nylock portion without first leaking around the washer and the bolt shaft. I don't remember ever seeing rubber in any of these nuts, Only brittle old nylock material (red). Somebody tell me if I'm off my rocker.

There are anti-vibration clips that go on these long bolts at the middle of the case split but again, not for sealing. They prevent the unsupported bolt span from resonating and loosening.

Thanks. Fortunately i have an extra split case to look at. Will do this week. I have the blue o rings from the gasket set as well as the washers. I can also swap out the old red sealing nuts for new nyloc. Just figure that there would be a source to replace the original, as there is in the vw world.

Posted by: Literati914 Aug 18 2019, 08:21 PM

QUOTE(worn @ Aug 18 2019, 09:03 PM)

... I can also swap out the old red sealing nuts for new nyloc. ...

Are there Nylocs in a high heat range by chance? Or are they generally robust enough to stand the heat from an engine?

Posted by: Tbrown4x4 Aug 19 2019, 06:53 AM

I wouldn't use a nyloc in a sealing capacity. Also, as mentioned, the temperature might exceed the nylon insert's ability to lock or seal.

I would be more inclined to put lots of sealer on both sides of the flat washer and torque the nuts to spec.

PS: I never understood how the seal on the new nuts was supposed to face away from the case. WTF?

Posted by: Mark Henry Aug 19 2019, 07:28 AM

I use loctite SI 5900 RTV never a leak.
Cleanup much easier than threebond/yamabond, con is it's thick and hard to press out with the 50ml tube. I use the caulk gun 300ml size but it's spendy if you only need a bit.

https://www.amazon.com/Loctite-Sealant-Engine-Cylinder-Porsche/dp/B015CC6WH0/ref=sr_1_1?keywords=SI+5900+Flange+Sealant&qid=1566220813&s=gateway&sr=8-1

Posted by: 73-914 Aug 19 2019, 08:21 AM

Nylocs are not for sealing. Used for anti-vibration

Posted by: Superhawk996 Aug 19 2019, 01:12 PM

QUOTE(73-914 @ Aug 19 2019, 10:21 AM)