Mercruiser Exhaust Riser Gaskets and Overall Engine Heat Load
Larry,
I don’t want to point fingers but the mechanic really doesn’t have a good technical understanding of the system and heat rejection fundamentals. The total area of the restrictor gasket is still larger than the area of the inlet water fitting on the bottom of the manifold (by design). Therefore both gaskets allow the same “total” amount of flow, its just directed differently. Besides that the castings have slots above the gasket which allows the water to flow around the restrictor gasket these days anyway.
Q = [(T2 – T1) * Cp] * M
Q = Heat Load
T2 = Outlet Temp
T1 = Inlet Temp
Cp = Specific Heat Of the Cooling Fluid
M = Total Flow
Hope that helps answer your question.
Regards
Performance Product Technologies/IShopBoating
8002 West 6th Street
Stillwater, OK 74074
(405) 533-3812
Fax (775) 257-1769
[email protected]
www.perfprotech.com
From: [email protected] [mailto:[email protected]]
Sent: Thursday, February 03, 2011 9:51 AM
To: PPT – Marine Engines & Parts
Subject: Contact Us Submission
Larry writes:
Hi andy, thanks for the last email, I just have one more question about riser gaskets. I was talking to a mercruiser mechanic & he told me to use restrictor gaskets because you need to hold back some of that water in the manifolds to help keep them cool. And yet others tell me you have to use the 4 open slot gaskets for full water flow through manifolds. Maybe you can give your take on this. thanks