Longshoe

iTrader: (2)

So having finally got my motor together, I was about to check end play when I notice one of the exhaust studs is at a weird angle. I wiggle it and and of course it falls off the housing. I look inside and its broken off pretty deep-- ive searched about stud removal but the only results I found were for studs that were either flush with the housing, or were sticking out a little. Id say the stud is about half a centimeter deep within the housing--which according to the pic of the stud on mazdatrix there isnt much left. Unfortunately there isnt enough thread to screw in a replacement stud.

Suggestions? Id rather not pull it apart and take it to a machine shop. Its soaking in PB blaster right now, waiting for me to attempt the reverse drill bit.

Aaron Cake

iTrader: (1)

Reverse drill bit is probably the best first choice. After that, you need to try some of those aweful "Easy Outs".

There are more expensive options if you can bring the engine to the machine shop like wire EDM and such. They won't require disassembly but will probably run a little more then $100.

Nismo Convert86

iTrader: (7)

How is a EDM going to remove a stud? It requires a hole to be drilled into the part thats going to be cut to feed the wire through it. So he will have a hole in his housing, and it would have to be dismantled.

Your best bet would be to build the stud up with weld since the weld will not stick to the aluminum housing (worse case you screw up the threads you can redrill, andput a helicoil in) , and once you have the weld crowning over the hole weld a nut to it.

Aaron Cake

iTrader: (1)

I may be using the wrong terminology, but I have seen stud removal using a machine very similar to an EDM machine. It erodes the stud out of the threads, leaving the threads intact. Very slick...

....just Google searched it and I should have said "MDM".

http://www.pci-energy.com/public/lea...y-services.htm

Or you can purchase your own EDM stud removal machine:

http://www.goencompass.com/edm_system.html

Nismo Convert86

iTrader: (7)

That makes much more sense, when I was working in a tool and die shop I was very familiar with the EDM machine. They are pretty cool.

RotaryEvolution

iTrader: (30)

you can also use a mig welder to weld onto the inside, weld a blob of slag onto the broken portion and then weld a bolt onto the slag, it has worked for me while the engine was complete and still in the car just had to cover the exhaust port.

Nismo Convert86

iTrader: (7)

Yeah, thats what I said in the first post I made, it's the easiest way to do it, and likely the cheapest.

RotaryEvolution

iTrader: (30)

sorry i missed that second paragraph.

Longshoe

iTrader: (2)

That sounds like a pretty good idea. Ive got a friend with a mig welder who might be able to do this for me. I dont know too much about welding, but the slag will not screw with the threads? Will it take the form of the threads when its 'molten'?

Nismo Convert86

iTrader: (7)

You should be fine, in the event it does happen, simply drill it out, put a helicoil in there, or use a larger diameter drill and tap to that dia., and you should be laughing.

RotaryEvolution

iTrader: (30)

i have never had an issue of melting the aluminum while welding with steel surrounding it.

Aaron Cake

iTrader: (1)

And the heat from the welding will go a long way towards loosening the stud as well.

Longshoe

iTrader: (2)

Alright, thanks for the info-- ill let everyone know what happens. Im going to try the reverse drill bit first before I go loading up the motor and bringing it to my buddy's house.