Can this be fixed? Cracked 3.2 Engine Case Around Drain Plug
 

Hello Pelican Parts brain trust!

I bought a 911 at auction which came as-is. Unfortunately, the engine case damage was never identified or described on the auction. It looks like something smacked the bottom of the engine pretty hard.

As of 3k miles ago, this was a very healthy engine so it would be unfortunate if this had to be pulled all the way apart for new engine cases.

What do you guys think, can it be welded? Or am I in for a rebuild?

Thanks in advance for your thoughts!

http://forums.pelicanparts.com/uploa...1553213906.jpg

Yes. But stripping the engine to the bare case to do it would be the only way to do it. (EDIT - the BEST way to do it.)

The worst way to do it would be a can of brake clean and some JB weld.

New cases........ might not be easy to find.

Glad to hear, thanks for your thoughts! I meant "new to me" if I needed a new case.

Haha, I'm not desperate enough to use JB Weld and am planning to pull the engine to do a deep clean and check. Should be a good time to get the case tig welded.

Ouch! Is that from over tightening the drain plug??

Interesting to speculate on what kind of a blow could cause a crack like that. Which direction did the force come from? Did it hit the steel plug, so as not to leave obvious marks on the aluminum? Could dropping or otherwise hitting upward on the flange do this?

I think you'll feel better with it tigged inside and out after everything is checked to be sure it is true enough.

Wow, it's amazing what some people are capable of. That case will have to be bolted together with both perimeter nuts and through bolts before it's welded on the outside. The crack will have to be grooved with a burr and cleaned to remove all traces of oil prior to welding including heating the crack with a propane torch to drive out any traces of oil from the casting. The only way to weld the inside would be to bolt the case half to a steel plate jig along the bottom perimeter to prevent warping. If it's grooved properly on the outside that shouldn't be necessary as the weld will penetrate to the inside assuming you find a good TIG operator.The drain hole will have to be re-tapped. Good luck.

Must be some recourse for a find like that?

Good luck either way

Easy fix for a good job shop, tear down motor throw it in parts cleaner or ultrasonic? Spray area with dynaflux crack check or similiar product. ( sometimes crack extends more than the eye can see without dye). The job shop will take care of the rest not a big deal or difficult job for a good welder.

Thanks for all the responses guys!

Who knows, in reality, it was probably a multitude of things but that might be what started it.

It didn't have any obvious marks on it which makes the whole thing really confusing.

Right? What you described is what all my research has led me to. Now to find a good welder and get the engine out of the car...

All the auctions sell their cars as-is so it may be difficult to recoup anything. The ECU was also missing, which is annoying but pushes up plans to go with a standalone.

http://forums.pelicanparts.com/suppo...s/beerchug.gif

I don't understand why there "must" be some recourse. It was an as-is auction.

Sorry if my last post sounded harsh.

Gabe - sorry about your misfortune on this.

I once purchased a long block 2.4 T motor at an estate sale. The owner said it was tired. When I got it home I found it had dropped a valve and holed a piston. It was more than tired...it was in a comma...I'm still in the process of trying to wake it up.

Hope it all works out.

could that be from jacking the car? I always fear this when I lift the back end of the car at about that exact spot.

My advice before welding is to dowel the 2 halves together across the main webs and bolt the case together. Otherwise you may have a banana shape case half after finishing.

Nah, it's not from jacking.

It's interesting that it's cracked through the drain plug boss and not around it as though a tapered thread plug had been installed and torqued to 11ty billion foot pounds

Are the drain plug threads in the case buggered? A welding job could be finished with installation of a Helicoil for the proper plug. I did that on a well known aftermarket drain circle plate (previous style) with deep aluminum fins - the boss inside was only half a boss, so there really weren't enough threads to hold much torque. It is the seal ring which keeps the oil in place, not the threads.

Not sure why anyone would screw with a turd like this when my repro cases start delivering in June. Sure, there are 36 people in line ahead of you to get one but I sure as heck would want to wait to get a good case rather than repairing that one. Shameless plug, but that is what my cases are made for.

Are you reproducing 3.2 cases?

JB Weld.

If its not leaky drive it like you stole it and wait until you need to formally address it.

"Not sure why anyone would screw with a turd like this when my repro cases start delivering in June."

Maybe because he'd rather spend maybe a couple hundred vs. $5K?

All good! My fault for not getting the car inspected ahead of time. I probably still would have bought it anyways. Hope you got a good deal on that 2.4t motor!

I doubt it, I'll find out more information when it's torn apart.

Is it any better to weld it that way than with the short block assembled?

Lol, those were my thoughts too. Could have been overtightened at some point and then had an impact...

They probably will be after it's welded together. Can probably just be tapped after that rather than helicoiled though. Not sure there is enough meat to drill and tap a larger hole.

Haha, believe me! I've been following your thread on rennlist for months (I have a 993 too). I'm not ready to do a more powerful build yet. I think the car would be too fast for me on a track and I want to learn with this one as I go. I imagine that I will go down that path at some point. Thank you for doing what you're doing!

I think it's almost as easy to have someone tig weld it with the case together and is a more permanent solution.

At this point yes... but it'd also be nice to grab one of those cases for $5k now and sit on it for a future build than $9k in the future.

Gabe, how is the case half on the other side, any cracks.

After I cleaned off the passenger side, I found a crack too http://forums.pelicanparts.com/suppo...leys/smi10.gif

This picture is a little more blurry than the other one, but you can see the much smaller crack.

I'm going to reach out to a few welding shops to see if they have a preferred method of attack, but my thoughts so far are:

• compression/leakdown test to make sure this is worth the effort
• remove engine
• degrease
• drill ends of cracks to relieve pressure
• grind the crack into a V
• heat the area with a torch to get rid of oil contamination
• have it tig welded
• move onto other aspects of this build

http://forums.pelicanparts.com/uploa...1553439876.jpg

Fair enough, but keep in mind that the price of a new case (mine or a porsche one) is directly proportional to the resale value of the car. No one is buying that car for anything but a steep discount with a cracked or even repaired case. No one will trust it no matter how well it is repaired. It'd damaged goods.

So here is how you fix it on the cheap:

- pull motor, dissasemble
- scrupulously clean both case halves
- grind out the crack so that you have a 1/16"-1/8" V profile for welding
- Bolt the case halves together with case perimeter bolts and case through bolts, torque to spec
- Weld the crack up. You can only do this well with very controlled rod passes, not sure I would use TIG. Either way, the welder you chose to do this will NOT be cheap.
-Dissasemble case, check halves for flatness, there is a good chance the case halves will need to be made flat after welding
- Double check main and layshaft bores for roundness and straightness.

This is the "cheap" method, $500 total if you pull and clean the motor yourself. There almost certainly WILL be machining involved or at the very least a machine shop checking the case.

To all the laypeople reading this, you don't weld on a Porsche case and expect it to remain in it's original shape without taking pains to ensure that it stays that way. That means checking it afterwards!

"Weld the crack up. You can only do this well with very controlled rod passes, not sure I would use TIG."

Are you serious??? Stick rod on an aluminum engine case??

3/32 2% lanthanated tungsten, 4043 filler, inverter TIG machine with AC balance and frequency control.

It looks like the crack extends thru the perimeter flange, that may present a problem when welding the flange with the two halves bolted together. May have to weld the majority of the crack with the two halves bolted together then use a steel jig plate bolted to the half when doing the flange.

Let us know how it turns out.

I would prefer a properly repaired original matching number case.

Try taking the drain plug out. If you can without breaking the bottom of the engine open. I suspect it will take a long breaker bar to get it out. It has to come out one way or another and will determine if the block is remitly saveable.

Chris

Like the cars in your signature?SmileWavy

Still have the original engine for the -77 for when the time is right.

The 69's engine is gone long before me... and its never going to be anywhere near original ever again, only original pieces are the drive shafts and steering rack.

Sounds to me like your one of those laypeople???
Wtf are you talking about I bet you don't even own a welder.

Catorce shoot me a pm with your email I'll hook you up, some of these guys are talking out their ass as usual. I know two aerospace welders that can help you out.

Did you mean the OP to send you an email, Catorce is the guy who wants him to get it stick welded with "very controlled rod passes":rolleyes:

What he said..

that's gonna need a full teardown and rebuild and there's no cheap or easy way to do it right. If it's leaky I'd try JB well until you're ready to bite the bullet. Also seriously consider sourcing a new case or motor as this may be financially better. The numbers matching thing is kinda moot since some future buyers may be scared by a weld-repaired case. I have to agree with Catorce, that motor is damaged goods and even if you had Dr Porsche come back from the dead and weld the case, there will always be doubt about the structural integrity of that case.

I've been in a similar situation with my old 356 motor and had to get a case welded after the motor fell off my engine stand during a rebuild. Fortunately my case tore off at the upper trans mount so it was a non stressed area and wasn't part of the crankcase. It was already out of the car and getting rebuilt, but it took a very skilled and experienced machine shop to fix it. It also required being fully disassembled and jig mounted for a proper repair.

Lol yeh my bad
Ahhhh yes maybe a migstick dip in the pass root leaving a very short tig allowance on the helistick while back purged with argyle radon gas. This will compensate for the serasodial cyclonic warpage. I would only attempt such a weld on Tuesday at 2:37 to avoid shim due to the the curvature of earth.

Thanks for all your thoughts guys.

I took all the plugs out and spun the engine over by hand yesterday, all good, so there doesn't seem to be internal damage. That said, I'd still like to compression test and do the leakdown. I'll make some calls to some local welders soon to see if anyone is willing to tackle this repair.

As for it being numbers matching, I'm not super concerned, the full value of this car fully went out the window with it's salvage title. My wife and I just bought a house so I've had to dial back the automotive hobby a bit. I'm sure I'll do a full engine rebuild at some point down the road but for now I'd like to get the car operational and enjoy it for a while.

I'll keep this thread updated as I learn more!

What about those low-temp aluminum brazing rods that i've started seeing at the budget tool stores? A propane torch and these rods put the process somewhere between soldering and brazing. Probably less chance to warp something that way. However, not sure how good a seal this offers but you'd be out about $15 to try it IF you have some leaking there.

I usually find that with repairs like this it's never a good idea to experiment with the repair. It makes it harder to fix a mess if things didn't work out the first time.

The case is going to have to be split. There is no way to weld that with oil residue on the inside of the case. The oil is just going to cook up to the surface causing lots of porosity in the weld puddle.

A couple options I'd explore if I were attempting this repair.

1. Fixturing the case or at least bridging the damaged area to a known precision flat surface and tacking in place.

2. Shuffle pinning to help keep things from moving. (as already suggested)

3. After shuffle pinning, tacking, and welding, check the case for flatness and or have the case halves skimmed and line bored. If you skim and line bore the case the intermediate shaft journals get touched up too.

I wonder if cracks like this could be from someone trying to jack up the rear from that point on the engine?
People do this all the time on front engine cars, and just jack up under the rear axle.

Leaving aside the economics, cases can be welded successfully. I had a big divot in a spigot, with some additional cracking upward toward the parting line (all due to a valve head falling off at speed on the track)welded up and remachined. My current 2.8LS has a non-matching numbers case - a good right mated with a good left. Whoever did this knew what he was doing.

With cracks on both sides, this is looking more and more like the engine was dropped a fairly significant distance onto something creating a sort of point load, without the headers/heat exchangers softening the blow.

While JB Weld, on first impression, sounds kind of nuts, maybe it would work for a long enough while to be worth trying given the owner's situation and plans. Drain the oil, of course. Maybe grind a V into each crack for more surface area. Clean the oil with solvents and rags from short sections and immediately pack in the epoxy. Do it again a short ways away, leaving a gap, sort of like tack welding. Then go back to the gaps, and one by one clean those an the surrounding JB hardened stuff. I'd spread the weld fairly widely for best grip.

First, I'd run the engine to see just how much oil leaks out and how fast. When done with the epoxy step, put oil back I the engine. See if there are static leaks from the get go. Then run it and see how that goes. As long as the drips are pretty slow, so you aren't oiling the highway and fellow motorists, and can live with cleaning a small puddle in your garage, and constant dip stick checking and topping off, maybe you can get what you need from the car for a while. Lots of us have various leaks in our air cooled 911s that we have learned to live with, though not to love.

And, if the epoxy just doesn't work - won't stick in places (maybe they didn't stay oil free long enough to get the epoxy on), maybe flaked off in others, etc., well you didn't spend a whole lot of money, and it shouldn't be a big bother for the machine shop when they get the case halves to weld.

Trackrat

I really don't think this is a result of jacking there. While I don't make a habit of it, when I remove only the engine I have the jack in this location. The case is older, so there is a plate there, and I made an adapter so it fits over all the nuts there so the engine will balance on the floor jack. On occasion, if I needed the car up a bit higher, I'd jack it up from here and move the jack stands or whatnot up a notch. This is an enormously strong structure.

On the other hand, this late 1983-1989 case, with the side drain, doesn't lend itself to jacking here. First off, why - the rear of the engine works fine, and is the standard way of getting both rear wheels off the ground at once. I guess if that didn't get the car up high enough, you might be tempted to jack where this broke. But it isn't set up so it is fairly easy to spread the load. But you might expect some kind of gouge or depression where something with a very small area was placed, and the owner says he doesn't see anything like that.

That case material is easy to tig. However you can kiss any sealing properties good bye, will leak oil due to heat burning the sealant away not to mention the distortion (shrinkage) will pull the seam apart a little. Thankfully a bit of distortion down there isn't going to mess with anything critical which is a ways above.