what is the id and od

[osidak]

I bought some replacement heat exchangers used. They have a thicker flange than my original exchangers.

I fear that if I try to replace the exhaust studs they will break. I plan on cutting the flanges off my old exchanger and welding them to the new exchangers using a sleeve on the outside of the down tubes. I would of course jig them to keep the same height and exhaust stud hole orientation(?)

What is the id and od of these down tubes and also do you think this is a good idea. If not what would suggest.

osidak
78 sc targa

[dad911]

I would bring them to a machine shop and see if they could mill the flanges thinner, or countersink the bolt area.

[osidak]

That was my first thought as well. The machine shop I went to didn't sound to sure that they could do it. That leaves me feeling even less sure they can do it if you know what I mean.

osidak

[Roland Kunz]

Hello

You bought 3,2 Heatexchangers or even 964 units.

I would just get the suiting hardware as you have to get bolts and gaskets anyhow. You just add 12 longer studs to the order.
The old studs can be removed with the correct tool and some patience. They mostly brake or come loose if you remove the heat exchanger.

Machinig down is more expensive and will lead into other troubles like the crosstube will not clear the tranyhousing and then the complete system will vibrate or pull the studs out from the heads.

Much simplier would be to have the correct part and not trying to fiddle non matching things investing more time and sometimes more money then it will cost at the next dealer.

If you have a machineshop at home this looks a bit different but then you just make 12 special long nuts and drill up the flange holes slightly.

Grüsse