Pelican Parts
Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   Pelican Parts Forums > Porsche Forums > 911 Engine Rebuilding Forum


Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Registered User
 
Emo993's Avatar
 
Join Date: May 2008
Location: Merrimac,WI
Posts: 642
Gabe, how is the case half on the other side, any cracks.
__________________
1974, 914-6 GT Tribute
2007 Cayman S
1998 993 Carrera S, speed yellow (Yellow Bird) gone but not forgotten.
2017 Golf Sportwagon 4motion
Old 03-24-2019, 03:33 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #21 (permalink)
Registered User
 
Join Date: Mar 2011
Location: Los Angeles
Posts: 29
Quote:
Originally Posted by Emo993 View Post
Gabe, how is the case half on the other side, any cracks.
After I cleaned off the passenger side, I found a crack too

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

Old 03-24-2019, 07:05 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #22 (permalink)
Registered User
 
Join Date: Apr 2016
Posts: 964
Quote:
Originally Posted by boosted79 View Post
"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?
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!
__________________
Current: 1970 914-6 conversion 2.7, 1973 T, 1975 930 Turbo Targa, 1978 928 Race car, 6.57L, 1983 911SC, 1987 928S4 5 speed, 2002 911 Targa, 2007 997TT, 2009 997TT, 2004 40th Anniversary Carrera, Mclaren 570S and 12C

Only reproduction 3.6 cases on the planet, coming soon www.taorminaracingdesigns.com
Old 03-24-2019, 08:06 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #23 (permalink)
Registered User
 
Join Date: Jan 2015
Posts: 1,367
"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.
Old 03-24-2019, 09:04 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #24 (permalink)
Registered User
 
safe's Avatar
 
Join Date: Feb 2004
Location: Sweden
Posts: 3,497
Garage
Quote:
Originally Posted by Catorce View Post
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.
I would prefer a properly repaired original matching number case.
__________________
Magnus
911 Silver Targa -77, 3.2 -84 with custom ITBs and EFI. Just works!
911T Coupe -69, 3.6, G50, "RSR", track day. Sorting out issues...
924 -79 rat roddy...
931 -79 under total restoration...
Old 03-24-2019, 10:43 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #25 (permalink)
Registered User
 
cmcfaul's Avatar
 
Join Date: Feb 2003
Posts: 1,422
Garage
Send a message via AIM to cmcfaul Send a message via Yahoo to cmcfaul Send a message via Skype™ to cmcfaul
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
Old 03-25-2019, 10:25 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #26 (permalink)
 
Registered User
 
Join Date: Apr 2016
Posts: 964
Quote:
Originally Posted by safe View Post
I would prefer a properly repaired original matching number case.
Like the cars in your signature?
__________________
Current: 1970 914-6 conversion 2.7, 1973 T, 1975 930 Turbo Targa, 1978 928 Race car, 6.57L, 1983 911SC, 1987 928S4 5 speed, 2002 911 Targa, 2007 997TT, 2009 997TT, 2004 40th Anniversary Carrera, Mclaren 570S and 12C

Only reproduction 3.6 cases on the planet, coming soon www.taorminaracingdesigns.com
Old 03-25-2019, 12:25 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #27 (permalink)
Registered User
 
safe's Avatar
 
Join Date: Feb 2004
Location: Sweden
Posts: 3,497
Garage
Quote:
Originally Posted by Catorce View Post
Like the cars in your signature?
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.
__________________
Magnus
911 Silver Targa -77, 3.2 -84 with custom ITBs and EFI. Just works!
911T Coupe -69, 3.6, G50, "RSR", track day. Sorting out issues...
924 -79 rat roddy...
931 -79 under total restoration...
Old 03-25-2019, 12:39 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #28 (permalink)
Registered User
 
Join Date: Dec 2014
Location: Syracuse,Ny
Posts: 1,918
Quote:
Originally Posted by Catorce View Post
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!
Sounds to me like your one of those laypeople???
Wtf are you talking about I bet you don't even own a welder.
Old 03-27-2019, 04:16 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #29 (permalink)
Registered User
 
Join Date: Dec 2014
Location: Syracuse,Ny
Posts: 1,918
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.
Old 03-27-2019, 04:30 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #30 (permalink)
Registered User
 
Join Date: Jan 2015
Posts: 1,367
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"
Old 03-27-2019, 04:43 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #31 (permalink)
Registered User
 
gshiwota's Avatar
 
Join Date: Apr 2005
Location: Huntington Beach, CA
Posts: 1,088
Quote:
Originally Posted by 996AE View Post
JB Weld.

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

Last edited by gshiwota; 03-27-2019 at 06:12 AM..
Old 03-27-2019, 05:56 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #32 (permalink)
Registered User
 
Join Date: Dec 2014
Location: Syracuse,Ny
Posts: 1,918
Quote:
Originally Posted by boosted79 View Post
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"
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.
Old 03-27-2019, 07:25 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #33 (permalink)
Registered User
 
Join Date: Mar 2011
Location: Los Angeles
Posts: 29
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!
Old 03-27-2019, 10:14 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #34 (permalink)
New-ish 911SC Targa Owner
 
pampadori's Avatar
 
Join Date: Jun 2015
Location: Richmond VA
Posts: 695
Garage
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.
__________________
'83 Targa 300k w/ freshened 3.0 with 930/52 case and ARP and Raceware hardware - AEM Infinity 506, Triumph T595 throttle bodies, B&B headers, Dynomax muff, Fidanza FW, Alum PP
'05 E500 wagon in minty cond
'13 Volvo XC60 (hers)
Old 03-27-2019, 10:19 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #35 (permalink)
Registered User
 
Join Date: Mar 2008
Posts: 1,004
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.
Old 03-27-2019, 11:02 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #36 (permalink)
Registered User
 
Join Date: Oct 2016
Location: Kansas
Posts: 1,150
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.
__________________
1987 Porsche 911 Carrera Coupe
Old 03-27-2019, 01:18 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #37 (permalink)
Registered User
 
Walt Fricke's Avatar
 
Join Date: May 2004
Location: Boulder, Colorado
Posts: 5,303
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.
Old 03-27-2019, 01:29 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #38 (permalink)
Registered User
 
Walt Fricke's Avatar
 
Join Date: May 2004
Location: Boulder, Colorado
Posts: 5,303
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.
Old 03-27-2019, 03:28 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #39 (permalink)
7.0:1 > 11.3:1
 
Join Date: Oct 2003
Location: Calgary
Posts: 1,938
Garage
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.
Old 03-27-2019, 04:32 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #40 (permalink)
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 


All times are GMT -8. The time now is 03:28 PM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.