Out with the old, in with the older, SS exchangers replacing '75 crapola Options

[rjames]

Finally got the old exchangers off. What a gigantic PITA. I figured they'd fall right off after removing the exhaust stud bolts, but noooooooo. It took about 1 hour of coaxing per side (and a ton of cursing) before they let go.

Here's the old: (IMG:style_emoticons/default/icon8.gif) (IMG:style_emoticons/default/barf.gif)

[rjames]

The heater stuff all bolts up after you get the exchangers and muffler on the car.

Thanks Dave, glad to hear this as it will make it easier to get the exhangers in there.

1.) I would leave any that are intact alone. Just be sure they don't rock from side to side. There may be other advice on this, as I am just working from a sample of one- my '76 that I backdated with SSIs.

The one you have to replace- you have options. Some are easier, but others may be better. When you say stripped, do you mean the stud stripped out of the head, or the thread stripped off at the nut?

2.) I didn't attach any of that stuff to mine yet. I hope it can all be attached after!!!!! I assume you have the early style ductwork? I don't think ANY of your late style will fit....

3. Believe it or not, it's only 14 ft-lbs. That's VW's spec, and it is also the limit for 8mm threads in aluminum. Unless you have a 1.8. They had 8mm/9mm step studs (according to the parts book anyway). A 9mm thread in the aluminum would probably be OK to 16 ft-lbs. If you go to the high teens or higher, there's risk of pulling studs from the head after a few thermal cycles. I guess others have gone higher and it's worked, but the engineering says stick to 14.

Also, save your nuts! My '76 had helinuts- a tall steel nut with helicoil threads inside. If that's what you have, they're reusable, and better than one piece nuts. The helicoil provides some flex to help accomodate for thermal expansion and contraction. They're more expensive, and you can bet VW wouldn't have gone with them if there wasn't an advantage.
Jim

Hey Jim, thanks for the reply. It's the stud itself that is stripped. When I was trying to tighten down one of the nuts on the exhaust studs it started to pull one of the studs out. I haven't pulled it out all the way yet, but either way I believe I'll have to replace it. Which leads me to the end of your post- I don't know if the original nuts are 'helinuts' but if they were lossening up on their own, then they can't be worth keeping. I ordered new ones from Pelican, along with the gaskets.

Glad you gave me the 14lb spec. Now I just need to go get a torque wrench as the one I have is for much larger torque applications.


Also, I do have all the necessary early style ductwork, it just needs some serious cleaning. Not sure how I'm going to do that- the insides of the ductwork have a lot of grease & grime. I got the outsides of the ductwork cleaned up but they need some paint now to rustproof 'em. I was thinking letting the stuff soak for a day in some degreaser, cleaning it up the best I can and then painting with hi-temp paint.
Is there another way I should go?