exhaust manifold questions here bolts and rust?

[mxcobra]

My setup is modified,- when I put it together I used bolts on the manifolds (Volvo) Should I switch to studs? why do I see studs for mounting these?
also taking it apart I found lots of rust in them scaled up, how could I flush out the cooling system periodically to slow or stop this?

 

[alldodge]

Marine motors use bolts so rust is not such an issue. If you use studs the nut and bolt will rust. When it comes time to remove the manifold, in most cases the studs snap off. Bolts have a better chance of being removed without snapping. Use bolts to install.

To make it easier to install, use thread rod or cut the heads off two long bolts. Place them on the outer holes and slide the manifold on. After installing other bolts remove the rods and install new bolts. Thread is 3/8-16 thread

 

[Bondo]

Ayuh,.... Many hulls have to much boat in the way to use studs, so bolts allow manifold swaps, In the boat,...

 

[bruceb58]

also taking it apart I found lots of rust in them scaled up, how could I flush out the cooling system periodically to slow or stop this?

If you boat in salt water, consider adding a neutra salt system.