Why the 3 inch riser block between manifolds and elbow?

[ardeprint]

I am intrigued as for the purpose of the 3 inch block between manifolds and elbow?

Anyone have a logical reason? I'm just curious.

 

[Southpaw II]

Can you be a bit more specific? Is this your boat? What boat/engine/etc?

Don

 

[ardeprint]

Mercruisr 350 MPI MEI, Standard cooling.

 

[Southpaw II]

If this is what I think, it is probably a "riser" to raise the height of the exaust to prevent the flow of water back into the engine. This is an effort to stop the water intrusion issue that has plagued so many Mercruisers.

Don

 

[tdschafer]

If this is what I think, it is probably a "riser" to raise the height of the exaust to prevent the flow of water back into the engine. This is an effort to stop the water intrusion issue that has plagued so many Mercruisers.

Don

I agree. I believe that this was placed to give a proper down slope to the exhaust and raise it high enough above the water line to prevent water ingestion from coming back in through the exhaust.

 

[Bt Doctur]

see page 12 and 13 .http://www.*******.com/merc/Install/gas/86016900.pdf
copy and paste, replacing the *`s with b,o,a,t,f,i,x .no comma`s