Weld repair to 4R case

[steinec]

Any data available on metal composition of a 4R case ? I need to do a weld repair-would like to know actual composition(magnesium, al, zn, etc) and recommended electrode for weld repair. Better yet, a good reputable shop in the Cleveland, Ohio area ?


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Pardon my sick, twisted and now cynical sense of humor, but.....
DO NOT, I REPEAT, DO NOT, EVER STRIKE A 911 engine with a 5lb sledge (whether in anger, frustration or just a simple attempt to move an oil crossover line so your SSI will slip on to the exhaust studs !!). One of the dumber things I have done lately, but certainly not the dumbest. I don't suppose this has ever happened to anyone else, eh ?

[BURN-BROS]

Can't give you the spec, but call the shops that work on planes. The smaller airports usually have someone that can do the repair.

[MBruns]

We had a case like that, we ended up machining the broken surface square and tapping the hole deeper and machining an outlet fitting that was longer to bring the height back, this one was a - 16, but you could do a metric fitting as well. BTW if you need a - 16 fitting I still have one of those fittings. Welding in that are is going to open up another bag of worms,from oil contamination to porosity not to mention the heat and distortion and cracking as a result.

Mike Bruns JBRacing.com

[Henry Schmidt]

Mike's suggestion will work. We've done it. If your going to disassemble the engine just replace the case if matching numbers is not an issue.
4R cases are available and relatively inexpensive.

[steinec]

Thanks, Mike, that's what I'm currently considering. It looks like there is sufficient uncut area in the port to tap some more threads but I am concerned about getting a sufficiently square and flat face for the crush washer to seal. Am actually thinking about pipe thread tapping and rethreading the hose conn. fitting nto pipe thread. Also concerned about the offset this will cause in the hardpipe-as you mention, I may need an extension to get it in the right place.

Also wondering about those brazing rods that are out there-there's one I found called HST-2000 that can supposedly repair this kind of damage without the amount of heat generated by GTAW/GMAW processes.

This motor needs to get me through this season, maybe 2, and I definitely don't want to blow it up from a weld repair failure at the sump outlet to the cooler. It's a good solid motor with boat-tailing and a bunch of other upgrades. It is replacing the original motor temporarily (which I pulled 2 weeks ago). Between now and next spring, I hope to do major work on the original engine-it's 100% original with 7R cases, 70K original miles, and even the original 5 blade fan and external regulator !

[MBruns]

As crunchy as those mag cases get/are its risky and would likely split out with pipe threads , I guess you are trying to do this without taking it apart ? If thats the case I might try tapping the hole deeper without cutting it down(for more thread engagement) custom make a longer fitting section going into the case and loctite it. the risk is it is scavenge out and a hell of an oil leak right at your left rear tire.
Mike

[mb911]

if you decide you need it welded We can do that for you We do mag on a regualr basis