Manifold temps

[cruzin1a]

5.7L 350 Mercruiser raw water cooled. I took it on the first ride last night. While running at no wake speeds I felt both manifolds and i cannot keep my hand on them because they are quite hot. The temperature gauge on the dask read about 150 degrees and staye steady. I did note that the hoses leading from the Thermostat to the risers are cold. Seems as if the Thermostat isn't opening. I will replace that tomorrow morning. My question is, if the cooling system is operating properly I was always under the impression you could put your hand on a manifold and it shouldn't be too hot to keep it there. Is this correct?

 

[four winns 214]

Re: Manifold temps

I recently started a thread about the same issue. I have a Merc 228R (5.0L) and the manifolds run 150-180F. Merc says that's ops normal for my engine, also raw water cooled. The impeller was changed this season and the engine temp is normal.

 

[FreeBeeTony]

Re: Manifold temps

Are you confusing the risers with the manifolds?
I don't think you would be able to keep your hand on the manifolds......risers yes, manifolds no.

 

[cruzin1a]

Re: Manifold temps

Thanks for the great input. Yeah I was always under the impression that you were supposed to be able to put a hand on the manifolds without it being to hot to keep it there. Seems as if I was under the wrong impression. I wish I had an infrared heat tool so I could post more accurate temps. The risers didn't feel too hot to touch but I will verify that when I go down tomorrow morning to install a new thermostat.

Thanks again!

 

[four winns 214]

Re: Manifold temps

...I wish I had an infrared heat tool so I could post more accurate temps.....

$30 at Home Depot will you have fixed up.

 

[cruzin1a]

Re: Manifold temps

I went out and bought the IR temp tool and took some measurements. I can take some more extensive ones maybe tonight. I saw a temp of 150 on the starboard manifold and 180 on th port manifold. As mentioned I will take some more specific temps maybe tonight when I have a chance to take the engine cover completely off. I have also replaced the Thermostat and some of the cooling hoses.