Hi folks, anybody remember me??? It's been over a year since my last "no progress" update, so I thought I'd give a little (and I do mean little) update. Haven't touched the project for quite a while due to other "distractors," but I do plan on getting back into it again.
The last RH exhaust manifold bolt was rusted/swollen up inside the manifold hole and I couldn't pry it free even though the bolt head was removed and drilled down below the outer edge of the hole. Previously, I had broken countless bits trying to drill the bolt to extract it, so that approach didn't help. Heating with a propane torch and walloping with a BFH hadn't freed it up either.
So today, I tried heating it up again, using MAPP this time, to free it. But no luck, it still wasn't hot enough. I guess you really do need acetylene to get it cherry hot! However, since I don't have an acetylene setup, I had to improvise. The manifold would rotate back and forth a few degrees around the bolt's axis, so I knew the bolt threads were moveable in the block. But the manifold casting would hit other parts of the block thereby preventing simply rotating the manifold CCW to back the bolt out of the block. At a loss for how to proceed, I decided to sacrifice the manifold itself to remove it from the block. Using the MAPP to hopefully soften the metal a bit, I used an air chisel to nibble away at the side of the manifold mounting hole along the length of the bolt. Then I was able to free it from the bolt.
Here's what it looked like about 3/4 through the job:
Looking closer you can see the outer part of the bolt is fused to the manifold while the inner threads appear loose:
Here's the freed manifold, regrettably now a piece of junk:
...and the remainder of the bolt which easily unscrewed from the block!!
I did notice this at the end however:
What could cause these two valve to appear so different?
Hoping to continue the saga...