Hole in case?? Help!
 

After getting my case back from the parts washer, I sat down to spend quality time with the case and clean it up. I immediately noticed an area that didn't look right. Looking closer, it seemed to me that the aluminum had been peeled back revealing a darker metal underneath. The area is a dime sized circle. The photos are difficult to read. I included three. Has anyone seen anything like this before?

The photos make it look like that a hole exists, but it is only the darker metal behind the case metal. The hole is on the right side of the case, behind the oil thermostat area.

I fear the worst. Can this be repaired?

remove the spaces from your file names and try again. If it's a Al case I'm pretty sure it can be welded

Here are the pics.


http://forums.pelicanparts.com/uploa...1079468475.jpg http://forums.pelicanparts.com/uploa...1079468497.jpg http://forums.pelicanparts.com/uploa...1079468517.jpg

Thanks l33t9eek!
It is from a 1980 3.0, so it is aluminum. I wonder how something like that happened? Is this common?

check this
http://forums.pelicanparts.com/911-engine-rebuilding-forum/151952-78-911sc-rebuild.html

where did you take this case to have it cleaned? Wonder if they used some harsh chemical of some sort and let it puddle in that area?

Chris

Hi Chris,

I took it to a local machine shop. They do work for the local area German car guys. They knew it was aluminum so I would hope they would not use anything too harsh. The case is much cleaner than before of course. No other areas look damaged at all. I am wondering what result this damage has on the oil system? This might have been the cause of my initial problem of spinning two rod bearings.

I've seen this on several 3.0L cases....

Here's another thread with this... http://forums.pelicanparts.com/911-engine-rebuilding-forum/154347-up-porsche-standards.html

It looks like some sort of steel sleeve. My case had it, others I've seen have it, and it looks broken, but every one I've see has that same thing.

I've not thought about what it is exactly, but seen to many to care now...

Are you talking about the small circular looking thing, almost like a drill hole? This is not a chemical cleaning thing, if thats what you are talking about.

Yes Jack, the darker area in the picture is the area in question. Apparently, it cannot be repaired. However, it does not adversely effect the engine as far as I can tell. There is steel sleeve behind the aluminum. Can't weld over that so says my machine shop.

I have learned so much in this project. I have learned that no matter what the pre-purchase inspection says, you just never know what you have until you take the thing apart! Even though the compression numbers were good at time of purchase ( 12%-18% variance across all cylinders) car had 132000 miles, I discovered the engine was a mess! The owner who owned the car for 12 years, stated that he engine had never been lowered out of the car ( no major work performed he said) Here I am looking at cylinder heads with new-ish springs and the valves needing to be replaced because there is not enough material left for grinding. On the rockers (6 to be exact) had the bolts were stripped so they could not be removed the ordinary way. A drill had to be used. How much are freakin new bolts for the rockers anyway??? Jeez, this car came from a 20 year member of PCA!!! Dude did me wrong!!!

Enough of my rant. I have certainly enjoyed this process of breaking down the engine, learning about new tools, learning about machine shop people ( cool but weird) and knowing for a fact that when I finish the engine for my 1980 911SC, I will have not taken any short cuts on this engine this time around. I'll be flat busted broke, but I will enjoy the heck out of the car once I get it on the road again!

Thanks to all who have helped so far!!!

What I think I see should be very repairable. Almost any case can be saved, even with damage to main bearing supports or other critical spots, unless the damage is gross. ITs usually a matter of what cost more, a used case (about $500 to $700, if you look around) or repairs. Even if yours cost $500 to repair, its a good bet as you then have a known good case.

The welder fills in the damaged areas with metal and then the machine shop remachines it The exact details can vary, depending on the type and extent of the damage. Sometimes a machine shop has to machine out an area so new material can be welded in and then remachined. Whatever, it can usually be fixed.

Hi Groovy,

That's a bummer, but I'm with snowman. It can be fixed. That condition may be a defect in the casting design. For some reason which I'm unaware of, the casting wall at those locations is very thin intentionally. I've designed aluminum castings [valve & pump housings] and when the metal flows into a thin section like that, it starts to chill [solidify] before you want it to. The result is a thin section that may visually look OK and have no strength, i.e. it can crumble under a high pressure stream or a sharp poke. Consult your machinist.

PS - I'm glad to catch this thread as I completed a 3.0 teardown today. Tomorrow, I'll be looking at these locations with my first cup of coffee.

Hi Groovy,

I think what your seeing is the steel insert that runs from the top of the case where the thermostat fits down to one of the pressure relief housings at the bottom of the case. My case has this and the steel is exposed in this area. Yours obviously wasn't exposed as much until the case was cleaned. I'd just clean up the lose bit of alloy around the edge and leave it. Won't do any harm, as long as no more alloy flakes off into your rebuilt engine.

Paul is correct Groovy. My case has the same appearance and George at Ollies told me that some of these cases have it and some don't. He also said that the steel insert Paul refers to is a "S" - shaped tube cast-in-place.

Gary

I'm with Paul and Gary. My 1980 case has the same condition.

Once I saw that knarled hole I freaked out!

Thanks for everyones input. I am going ahead with my cleaning and re-build!

-Alex

I do not accept this remark from anyone: "It cannot be done."

I've even heard computer guys say it. The truth is found in the posts above. Sometimes repairs are more expensive than replacements. I'll accept that. But when someone says to me "Impossible, cannot be done," I sometimes just walk away. Sometimes muttering "Yeah, well somebody's gonna do it."

Alex,

My '78 case has the same opening on the inside. Prior to opening it up she was also leaking from the same passage that is exposed on the outside of the case. I think that anyone who sees the inside of their case like that needs to seal up the exposed tube that is visible from outside the case.

http://forums.pelicanparts.com/porsche-911-technical-forum/98501-source-oil-leak.html

Thanks Simon,

I want to have the case repaired. I have dissassembled the engine and am spending major money (to me that is..) replacing worn parts and machining, not counting my time. Were you successful in sealing the outside?

Hello there.

The steel tube is for some reason holed.

What exactly did they use to clean the case I wonder?

It is an easy repair though as it only needs to be oil tight.

I'd do it with an ali lump carved to fit tightly and epoxy glued in place with three tapped holes around and small bolts in them.

Should take about two hours in all.

I would not weld this.

Kind regards
David