If they are stock 502 MPI's,,,,,, dont do it !!!!!
As obnoxus said, leave it stock. You are going to gain nothing but headache's from messing with what Merc has done. Crossovers look nice, but they can cause issues with water temp and water pressure. If they lower the water temp they will mess up the computer as it needs to read a certain temp.BB Thunder said:Thanks for the reply.
Being new to the MPI what are the dangers with doing the SS water bypass and thermostat housing install?
I have a set of Mercruiser Gill headers that i will also be installing.
That hose can have a combination of heated and any excess water not going thru the motor, which would be cold lake temp water. Can give the ECM a false temp reading, and as previoulsy mentioned, EFI's need the correct temp reading for fuel mixture.BB Thunder said:The engines are 1995 Mercruiser 502 Mag MPI.
I was considering fabbing an in line 1 inch Tee in the water discharge hoses to the manifolds -close to the thermostat housing on each side.