Hose to exhaust manifolds

[Gonefishing85]

Early 90's omc 5.7. Does anyone know what the I.D. is for the hose that supplies water from the thermostat housing to the exhaust manifolds? This is the hose after the T that connects directly to the manifold.

 

[Scott Danforth]

Either 3/4 or 1"

 

[Lou C]

I think they are 3/4” the only one bigger is the raw water intake hose...

 

[Gonefishing85]

I think they are 3/4” the only one bigger is the raw water intake hose...

I have a closed cooling setup so I do have 2- 1.5" hoses but most are 3/4". Without pulling them off, I can't determine if hoses going to the manifolds are 1" or 3/4". Of course the part #'s associated dont provide dimensions.

 

[Scott Danforth]

you need to measure. you can measure the outside of the hose a 3/4" ID hose is about 15/16" od and a 1" ID hose is about 1-3/16"OD however for the most part its just heater hose.

 

[Lou C]

Unless something changed between '88 when mine was made and when yours was made, the hose fittings on the manifolds are 3/4" id as are the hose fittings on the thermostat housing that are for the manifold hoses. I bet 3/4" or 19mm id heater hose would work just fine.