| Author |
Message |
Bill Sebestyen (Bill308)
| | Posted on Saturday, November 03, 2001 - 6:15 am: | |
Peter,
So you stress relieve the crack tips prior to welding? That's interresting.
Cobalt drills work well on stainless. You can get them at Home Depot or better hardware stores.
Bill |
'75 308 GT4 (Peter)
| | Posted on Saturday, November 03, 2001 - 12:49 am: | |
Drilling stainless is a bit--, use a slow-speed drill and cutting fluid, press down with constant, firm pressure. Wear saftey glasses (I've had too much debris fly in, even with the things on, but they've saved my eyes many times).
Damn, giving away too many trade secrets... |
'75 308 GT4 (Peter)
| | Posted on Saturday, November 03, 2001 - 12:44 am: | |
I forgot to clarify a few points:
This would be done with TIG welding.
Of course, in addition to the back-purge, you have the sheilding gas flowing out the TIG torch.
Scrupulously clean all old weld and exhaust carbon deposits.
For the time-being, you can drill a small hole at the ends of the cracks to keep it at bay and from spreading further (this should be done at the time of welding too. The start of the weld is usually the coldest - if not done properly - and the weld may not penetrate through, thereby, the crack can continue along the tube). Extra holes make extra noise J. Just joking. |
'75 308 GT4 (Peter)
| | Posted on Friday, November 02, 2001 - 11:50 pm: | |
I'm in the midst of repairing Larry Dunn's headers from his GT4 (actually I haven't touched them in a while, sorry Larry, I'll get 'em done.... other projects! J.
Nothing can't be welded. His headers are stainless, the best filler rod to use is type 304 or 308, type 312 if its a mild steel flange to the stainless tube. Back purge (by filling the exhaust tube with the sheilding gas - Argon). Without purging, the carbon in the stainless will precipitate out, causing it to rust and crack!
With the higher heats genrated for emissions equipment (I know your's is a Challenge, but I'd doubt if they'd use a different material). It could be Inconel, or some other alloy. With the proper machine (Miller Syncrowave or better yet the Aerowave) and operator, it can be fixed. |
magoo (Magoo)
| | Posted on Friday, November 02, 2001 - 9:06 pm: | |
Ask Peter GT4, He is a professional welder by trade. If anybody knows, he does. |
Jon P. Kofod (95f355c)
| | Posted on Friday, November 02, 2001 - 6:24 pm: | |
Rob,
I have not seen the damage this time around. I was way over the decibel level this past week at Summit Point and got a call yesterday from Ferrari of Wash. I will be going to the dealer on Monday to look at how bad they are cracked and will then post pictures here on the board to get peoples opinions.
Regards,
Jon |
Rob Lay (Rob328gts)
| | Posted on Friday, November 02, 2001 - 3:29 pm: | |
Did you try several shops to get them repaired? There's a bunch of really good shops out there that specialize in this type of repair. Granted, none of them have ever seen a Ferrari head before, but the techniques are the same. |
Jon P. Kofod (95f355c)
| | Posted on Friday, November 02, 2001 - 3:13 pm: | |
I cracked the headers on my 355 C. Anyone know where I can get headers other than from FNA. Ferrari of Washington wants $3200 for new headers. Any of you know some race shops that might sell them.
Mine cannot be welded (already tried it!)
Regards,
Jon P. Kofod
1995 F355 C #23 |
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