Exhaust Manifold Bolt torque

[Erie Canal Boater]

Repalcing the exhaust manifold gasket on a 86 mercruiser 470(yes the dreaded 470) anyway does anyone know what the spec is on how much torque to apply to the bolts?
I assume you tighten from the center out correct?
Do you apply any gasket sealer or not t? The mechanic at the local marina said no.
I have cleaned all the old gasket off and have polished with steel wool so I have a smooth contact surface.
Any advice would be very helpful.

 

[Coors]

Re: Exhaust Manifold Bolt torque

I don't know the specs, some will come in, but, steel wool no good.
Get a long file and clean, you can tell better if the surfaces are flat- if not, that needs work.

 

[Erie Canal Boater]

Re: Exhaust Manifold Bolt torque

I msispoke I actually cleaned with a razor blade wd/40 then used emory cloth over and over then polished w/ steel wool till it was smooth and shiney.

 

[Coors]

Re: Exhaust Manifold Bolt torque

You still need to check it for being a flat mating surface.

 

[Bondo]

Re: Exhaust Manifold Bolt torque

does anyone know what the spec is on how much torque to apply to the bolts?

Ayuh,......

They're 3/8" bolts,..... Torque is 35/ 40ft.lbs......
7/16" bolts torque to 45/ 50ft.lbs.....