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Posted by: worn Jul 28 2014, 01:46 PM

Can any one out there comment on the idea of cutting off the 6 inches or so of the heat exchanger where it meets the heads and adding flanges there so that the exhaust can be dropped without disturbing the head joint?

I have a spare set of heads so I ws thinking of mounting the heat exchangers, slicing and then tack welding the flanges while still in place. I was thinking of using V flanges with rings as well so you could still get to the head studs with a socket.

Ideas?

Posted by: McMark Jul 28 2014, 02:05 PM

It'll work as well as you can weld and fabricate.

Posted by: stugray Jul 28 2014, 02:07 PM

With the massive PITA of removing these exhausts and the risk associated with messing up the studs, I have thought about this myself.
I am even keeping a nasty old set of HEs just for this purpose

Posted by: worn Jul 28 2014, 05:13 PM

Yeah. Well I tend to agree with that one.
Given that I pull it off - is it a reasonable idea? I find that I want to pull the exhausts to do things like check the valves, replace an alternator and track down pesky oil leaks. Now that I am backdating to 1974, I am not gonna have the two into one sink p trap to disconnect anymore. Thank goodness!

Posted by: Racer Chris Jul 28 2014, 07:05 PM

The port end of SSIs is rather flimsy.

Posted by: worn Jul 28 2014, 07:54 PM

Meaning they wouldn't make strong stubs? What if I used the port ends of stock 1976? I appreciate that you are following this Chris. Trying to put together a six and keep the 4 running at the same time has required bargain hunting. And of course I like experimenting too. Haven't the er thingies to drive as fast as you do though.

Posted by: Racer Chris Jul 29 2014, 08:04 AM

Exactly.

I guess, if you can make them fit up to the HE pipes.

Posted by: worn Jul 29 2014, 08:38 AM

Would it help to tie the two stups together with a cross brace? Assuming room which I am not so sure of.

Posted by: rick 918-S Jul 29 2014, 08:54 AM

Expansion and contraction may be dissimilar from the heads. By locking the two together it may cause a leak. It's a puzzle with lots of trial and error to get it right.

Posted by: rhodyguy Jul 29 2014, 08:55 AM

i think if you take 6" off of the head ends of the heat exchangers you'll be into the bottom curve of the pipes. you're going with stainless?

Posted by: worn Jul 29 2014, 10:08 AM

Yeah, I would say that is correct. I have experience welding stainless, and thought it worked well. I might fill the tubes with argon. The welds will be to flanges, not directly joining tubes.

The curve is a problem. One solution would be to cut the stock stubs off at the point they start to curve and join to a straight point on the new stainless. That way, the HEs would drop down and that might magnify the problem.

I ordered the flanges, but I have a lot of things I never used...

Posted by: lonewolfe Jul 29 2014, 01:17 PM

I've thought about doing this to my car as well. It would be cool to be able to run heat exchangers in the winter and then headers during the warmer months. I was thinking of using stubs from a European Racing header. Those damn studs break too easily when removing the exhaust. Is there a type of exhaust stud that is not so fragile that could be put into the heads?

Posted by: rhodyguy Jul 29 2014, 07:03 PM

Remember that the j- tubes, branch ducting, warm air elbows will all be dropping too. You'll have make it all work and connect to the fan shroud. Heat control wire too.

Posted by: worn Jul 30 2014, 07:36 AM

Yeah, we kinda ruled that out last night drawing on a paper bag. My son asked: is this common? It seems convenient. My comment was I had seen it in some of the higher quality headers. Never seen an add on to HEs though. Odd. I am always the last one to know etc....

Posted by: worn Aug 3 2014, 08:54 PM

I measured a set of ss heat exchangers, vendor fuzzy. I got a wall thickness of 0.080 The stock came out as 0.125 That would very strongly substantiate what Chris said.

The whole point is to leave the joint at the head unmolested while pulling the exhaust.
Query: is this really worth a stub joint and flange effort?
Query 2: Why do we see stubs on the better headers if not for this reason?

I have discovered I can make it work with ss HEs. Do I want to?

Posted by: 7TPorsh Aug 4 2014, 12:32 PM

Don't the later models already have a two into one setup like this?

Posted by: SKL1 Aug 4 2014, 12:55 PM

Didn't someone make aftermarket headers and exhaust sytem that did just that? I remember looking into that system a couple years ago, but apparently the guy who made the system died and the idea must have died with him...

Posted by: worn Aug 5 2014, 07:09 PM

This would be a one into one setup to get rid of that. I am backdating a '76. But yes, I would like to retain that stub aspect.