broken/chipped case on oil connector hole
 

Hi all, I did some searching and couldn’t find if anyone’s had this specific issue before. Car is a 77 with a 80 engine. I took it out to have some trans work done, clean it up and install ssi’s and itbs. When I took the old heat boxes off I noticed the case was chipped around the oil connector. The old connector had Teflon tape and blue silicone around it. Looks like 2-3 full threads was all it had to hold on too! Didn’t have any major oil leaks. Some advice on how to fix it would be very appreciated.
Backstory is the car has 195xxx miles but don’t know any history on the motor besides it’s not original. Should I split the case for a shop to tig and machine? And have a full rebuild as well. I am in Vancouver Canada so parts come at a 30% premium with exchange rate. I have abt 15k cad or 11k usd. How would someone with much more experience working on these cars go about it with this budget?
With many thanks,
Isaac

http://forums.pelicanparts.com/uploa...1701844554.jpg
http://forums.pelicanparts.com/uploa...1701844554.jpg

Will you be doing the work, other than TIG welding and recutting the threads?

As you can see, the fitting goes into the case, then the return pipe screws into the fitting.

I would first throughly clean out the area and then screw the fitting in with JB WELD. It should work. Thereafter, don't try to remove that fitting. What broke the case in the first place probably was someone trying to remove that fitting with a lot of torque. Probably using an impact wrench too. I see no need to ever remove it.

If you split the case, you will end up doing a rebuild, but there are ways to hold down the cost by reusing good parts. If you don't have damage to fix, then you can stay within your budget by doing most of the work yourself. If the engine was running well, and has good compression and/or leak down numbers, I would reuse the main and rod bearings if they don't show signs of wear or contamination. Check them with Plastigage when you do your test reassembly of the case. Same for other internal parts and timing chains. Same for the pistons and rings (make sure you keep track of which rings go on which piston and which cylinder).

If you have a Porsche shop rebuild it for you, they will insist on using new bearings and other parts, and I don't criticize them, because they have a reputation to protect and want to minimize the possibility of "come backs." But I am sure it will bust your budget.

At 195Kmi, you can count on refreshing the valves, guides, valve seals, and the rockers. It may be necessary to machine the sealing surfaces of the heads, and you may need new cylinders if the top edges are worn or pitted. If it's a 1980 engine, it probably has the Dilivar head studs on the bottom row, and you definitely should replace those with regular steel Porsche studs.

Obviously, you will face a lot of temptation to improve things "while you are in there." Let your budget be your guide.

Please don't start two threads on the same subject, as I replied to the other one first.

Thanks for the advice, Yeah the first one posted without pictures and couldn't see where to delete a post.
I’ll be doing the work besides the machine work if I decide to do that instead of jb weld.

Keep an eye out for a replacement case.

I’m with John.

Same here. I would JB Weld it to get you out of trouble, but look for a new case.

Why the big love for JB on something serious like this?

What other option does he have other than a new case? In the short term this might keep him going until he goes down that road. Any other ideas?

You jb that piece in, holding on with only a couple of threads, from the looks of it, then you have to install the return pipe onto it and tighten it real well, which will likely break whatever sketchy bond the fitting has. Just a thought. Short term for sure.

John, I don't "love" it, but I am suggesting it to him as an interim solution. He said it held together and not leaking with silicone sealer before he unscrewed it, so JB Weld should work much better than that. And it may last many years. It costs almost nothing, and if it doesn't work, he's no worse off. A replacement case would necessarily require a full rebuild, which would substantially exceed his budget. Which means "fuhgeddaboudit."

Story: I punched a hole in the aluminum oil pan of a 2005 Chevy Astro van on a road trip. Getting a replacement oil pan would have taken a couple days, and I had to get home. So, I asked the shop to patch it up with JB Weld. It got me home, and then I drove the vehicle for five more years like that.

That fitting on the case is not subject to high oil pressure, otherwise I'd be less inclined to suggest it. The pipe that screws into it is held by tabs at two other points, which relieves stress on that joint. If he has two or three threads, plus the extra JB Weld built up around the joint, I'll bet it never leaks. Keep an eye on it, of course,

Not a lot of pressure, but it's the oil return to the tank and if it pops loose while driving, all the oil would be dumped in less than a minute. Not worth the chance in my book.

Are you feeling lucky?

Scavenge isn't necessarily low pressure, by the way. Granted, during normal operation in a warm engine - yes, it's lower pressure than the pressure side of the system.

But ... think of a cold startup in cooler weather, with a large amount of oil pooled in the sump as 911s tend to do. First thing the scavenge pump does is empty the sump of course. No sloshing or air to pump, just cold, thick oil. Remember, the scavenge side of the pump is bigger than the pressure side, and there isn't a pressure relief of any kind on the scavenge side. I recall someone measured scavenge pressure for a cold startup and it pegged the gauge, can't recall the scale but definitely at least 100 psi. I've also heard of oil coolers and filters exploding from cold startups (granted rarely). How much pressure does it take to do that?

Isaac,

That is a engine disassembled type repair, by specialist machine shop. Can absolutely be done, but not within your budget. Well, it could be done by disassembling, repairing the broken area, and reassembling with ALL the original parts with the exception of gaskets and sealants. Feel free to give me a ring at the shop or swing by to chat engines. We are out in Langley.

Cheers

I think there is a question to be asked:
If I had the budget I would replace the case. Easy answer. If the budget doesn't exist and another case is the only option, there is no joy in Mudville...the Porche just sits.
Can the case be repaired sufficiently to perform leak free and safety without disassembling the engine and if so why not do it.
If it were mine, I might try grinding/machining the broken area smooth (a modified end mill with a centering pilot might work), use a tap to increase thread engagement in the case and try to torque the fitting. If it holds significant torque, install a new sealing washer, add some Loctite 574 to the threads and reinstall the engine.