Re- Torquing the exhaust manifold and raisers

[kkalsch]

4.3 MPI Alpha I Gen II -This spring I installed all new mercruier exhaust manifolds and raiser's using the silver gaskets from merc. I followed the service manual directions and no wear did it state to re-torgue -Well I put about 5 hrs on the boat and decided to check the torgue. I could not believe how far off the torgue was -is this normal? and can you ruin those silver gaskets by re-torguing?

Thanks

 

[Brentathon]

Re: Re- Torquing the exhaust manifold and raisers

I just re-torqued mine (after 1 season), because I was just made aware of the service bulletin specifying the higher torque. I don't know if they loosened, but I know I barely had to tighten them to go from the original 25 setting up to the new 33 ft-lbs.
So, I don't believe they loosened much, just from feel.
I doubt these "graphoil??" gaskets take a set (much), nor would I think they creep or get squeezed-out, so I would think if you re-torque or check torque, it's probably not going to hurt much.
I would think, that eventually, they should hold the torque value, though.
The elbow gaskets are scary........I wouldn't want a leak with them, and get saltwater into my exhaust valves.

 

[kkalsch]

Re: Re- Torquing the exhaust manifold and raisers

From some of the research I have done -it seems a lot of folks .. re-torque after the first heat -cool cycle and then maybe 20 hours after that. I was hoping for some wisdom from the gray beards ......but I guess -Any re-torque is better.......than no re-torque at all... LOL