986 Forum - The Community for Porsche Boxster & Cayman Owners - View Single Post - Exhaust manifold studs pros and con questions....

ike84 · 05-31-2021, 06:20 PM

As blue said, go with copper nuts (not stainless). The reason for this is that same composition metals will undergo "cold welding" under high temperature and pressure, whereas dissimilar metals (i.e. steel and copper) will not.

It's a neat process. It happens in a total vacuum. Touch two steel rods together and they become one. Here, the heat and pressure just serve to drive it all the oxygen molecules out from between the iron molecules.

Knowledge is power!

Btw, the downside of using threaded rod instead of actual studs is that the studs have a hex head cut into the end, whereas the rods will require double nuts to torque and loosen.

I used m8 x 50 mm studs for a Ford V8, cost $15 for the dry on Amazon.

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05-31-2021, 06:20 PM	#8
ike84 Registered User Join Date: Oct 2020 Location: KY Posts: 1,216	As blue said, go with copper nuts (not stainless). The reason for this is that same composition metals will undergo "cold welding" under high temperature and pressure, whereas dissimilar metals (i.e. steel and copper) will not. It's a neat process. It happens in a total vacuum. Touch two steel rods together and they become one. Here, the heat and pressure just serve to drive it all the oxygen molecules out from between the iron molecules. Knowledge is power! Btw, the downside of using threaded rod instead of actual studs is that the studs have a hex head cut into the end, whereas the rods will require double nuts to torque and loosen. I used m8 x 50 mm studs for a Ford V8, cost $15 for the dry on Amazon. Sent from my POCOPHONE F1 using Tapatalk __________________ 2000 Box Base, Renegade Stage 1 performance mods complete, more to come When the owners manual says that the laws of physics can't be broken by this car, I took it as a challenge... Last edited by ike84; 05-31-2021 at 06:24 PM.