Turbo oil return...suggestions please

[gavinc69]

Hi guys,

I've been returning the turbo oil to the sump via the sump plate with no issues at all for the last year other than a small leak.
The sump plate was modified to have an AN-8 connection and there has always been a small leak from this point. After several attempts to seal the threads using 3M thread sealer I started to suspect the welds around the AN-8 fitting.

I'm at the point where I either remove the sump plate and get it redone or I find an alternative.

I was originally going to return back to the oil tank but after several attempts and different methods gave up.
I've just thought of a possible simple solution and wanted to get some input from people in the know.

Current setup :





I have seen someone put a 90degree AN fitting on the sump plate drain plug fitting and return that way but it appears to hang down a way and I'd be concerned it may get knocked.

So I was thinking that as the 930 returned oil back to the tank with a dedicated fitting low down on the oil tank I could use a M22 x1.5 to AN-8 fitting on the oil tank drain plug fitting , then use an AN-8 90degree fitting.
I'm using a Turbowerz pump to scavenge the oil. If need be I could use a check valve to stop oil draining from the tank back to the turbo catch can and as the magnetic drain plug would not be used I could install a Turbowerx inline oil filter that also has a magnetic ring to remove metal particles.

Exa-Pure™ 100µ Filtration System





So what does everyone think, any advantages or disadvantages in neither way?

[copbait73]

I'm a big supporter of find and fix the leak over abandoning something that works.
Go to the auto parts dealer and get dye to add to your oil. Clean the affected area and use a blacklight to identify the exact location then stop it with appropriate action.
Be prepared, once you have the method and tools owning an old air cooled motor may drive you nuts chasing all the other leaks. Just stick with the big ones and save your money for a complete overhaul to fix the "residue" leaks.

[911nut]

The angled portion of the male fitting is where the sealing occurs, not the threads.
Check your hose end fitting for damage. The temptation is to keep reefing on them when they leak, which can easy to screw them up. If it's hosed buy a new one (even a steel one if you can) and tighten it gently.

[JFairman]

Originally Posted by 911nut

The angled portion of the male fitting is where the sealing occurs, not the threads.
Check your hose end fitting for damage. The temptation is to keep reefing on them when they leak, which can easy to screw them up. If it's hosed buy a new one (even a steel one if you can) and tighten it gently.

This is true. Over tightening AN fittings, compression fittings, and conical fittings will damage them and they can sweat or leak afterwards. The swivel part of the fitting gets distorted and then leaks.
Also, mixing brands of AN fittings can cause slow leaks and the low cost Chinese copies of AN fitings you see these days are hit and miss and will probably slowly leak.
Aeroquip and Russell are top quality and used to be the only ones out there. Aeroquip was and probably still is the best.
You get what you pay for with them.

[gavinc69]

The drips are forming just at the bottom of the weld here :
There is no oil at all over any of the AN fittings or between the the fittings.



May just take the plate off and get it re-welded and also install new branded AN fittings then just incase.

[copbait73]

If you are convinced it needs re welded take it to someone who can do a nice TIG weld. It's not just about looks, better than MIG at avoiding pin holes.

[JFairman]

Looks kinda like a thick coat of enamel paint brushed on to it. Soak it in paint remover first and remove it all down to bare metal so it doesn't get all burnt and cooked on and make a mess of it while welding or brazing it.

If a weld is leaking it's probably just a pin hole in the weld. I would just get it red hot with an acetylene and oxygen torch and braze over the weld without melting the steel with a flux coated brass brazing rod.
That would seal it up good without disturbing the current weld but either way will work.
Then repaint it or powder coat it.

[JFairman]

Copbait and I posted at the same time.. I always like his posts. He's right about tig welding being the best.

I suggested what I would do because I don't have a tig welder at home but I do have a small acetylene and oxygen welding and cutting kit.
I occasionally use it for rock ape welding with old steel coat hangers you get from the dry cleaners or brazing with flux coated brass rod so thats where I was coming from
..and sometimes I use it for burning the baffles out of mufflers with the cutting tip so they flow better.

[Uncle]

I agree with the above. What you have done works so just make it better mate. If you do go another way you could TIG a fitting onto the timing cover but again it's just re-working what you already have.

[patkeefe]

The filter will hinder your return. Looks like you have a small bit of porosity in your weld. I have had this, and I just wire brushed the paint off, cleaned it really well with MEK or acetone, and brushed a layer of JB weld over it. It is easier than grinding the welds back down and rewelding it.

[911nut]

The oil drip will appear at the lowest point thanks to gravity. It doesn't necessarily mean there's a hole in the weld.

[unclebilly]

If you have porosity in your weld, you won't be TIG welding it up... The oil will contaminate your welds. MIG will have similar challenges. I had a similar problem with porosity in the weld on an engine mounter oil cooler on my first 911.

It's too bad that they made this the way they did. They should have drilled a hole through the plate, put the fitting through the hole and TIG or MIG welded up the inside of the plate. This would have done a much nicer job and would have been far less prone to weld contamination.

[gavinc69]

I've ordered a new sump plate and will look at options. If I go the same route as before I'll use the new plate and a new AN-8 connector so no chance of contamination from oil

Thanks for the feedback all.

[gavinc69]

New sump plate and AN-8 weld in fitting arrived.
Will drop them off to the welder this weekend and ask for a TIG weld.

[gavinc69]

Old sump plate off and just for reference I fitted the M22 x 1.5 to AN-8 adapter and AN-8 90degree fittings. Much more reduced clearance compared to the welded fitting :

[copbait73]

That just looks like a recipe for disaster. Instead of a few drops of oil here and there you'll have a large puddle after a speed bump or worse a failed engine. Too low and exposed, re-do what you had.

[baloo]

has anyone ever tried returning the oil to the side of the case rather than from underneath? if nothing else, this would prevent complete drain out of oil if the bottom fitting were hit or just leaking.
it would depend if there is enough side clearance to drill and tap into the crankcase.

[copbait73]

Originally Posted by baloo

has anyone ever tried returning the oil to the side of the case rather than from underneath? if nothing else, this would prevent complete drain out of oil if the bottom fitting were hit or just leaking.
it would depend if there is enough side clearance to drill and tap into the crankcase.

I have a custom K16 installation on my 2.4L CIS and I have it installed high enough to gravity drain back to the left chain case. Never had a problem with it. I don't think there is adequate drop using the stock mounting location and the larger framesize turbo.
I enter the chain case with a fabricated flange/tube, no room for fancy fittings.

[gavinc69]

I posted the image just as a reference so people can see the difference in clearance between the two types of return points.
I won't be using the AN 90 degree fitting as its way to low. This was stated as a concern earlier in the thread.
I have new sump plate and AN-8 fitting (pictured above) that will be welded as per the first plate.

[patkeefe]

Originally Posted by baloo

has anyone ever tried returning the oil to the side of the case rather than from underneath? if nothing else, this would prevent complete drain out of oil if the bottom fitting were hit or just leaking.
it would depend if there is enough side clearance to drill and tap into the crankcase.

I return mine to the left side chain cover. Coincidentally, I was just out in the garage doing the start up for the first time since reinstalling the engine. I can't pump enough oil from the turbo through my electric pump without it pushing past the bearings to the exhaust side. I used to run a catch can, but figured I'd try this first. Catch can = more clearance issues. Oil return is such a PITA.