risers and manifolds temp 1997 350

i have a 97 350 gm carb, while i had the muffs hooked the other day, i noticed that one manifold was hot, u could leave your hand on it, but the other one was cool,while running the engine, the temp on the gauge was 150-160 normal thats about what it runs, is this a concern?? thanks for any input

Re: risers and manifolds temp

Not the same engine but perhaps my information is of some use to you. I find that on the Merc 7.4 MPI that I just took out that the port side ran hotter than the starboard. The deal is that there was just a bit more resistance to the raw water path on the port side. I'm saying this since the hoses are longer/more turns to that side which matches which side is hotter.

Also, what i do is keep an eye on what the nominal temps are on my engine so that as it gets warmer I know that something is getting plugged up. In the most recent case, it was the risers and elbows.

The temps you mention sound a bit warm. But the real question is what it does under load underway.

I'm sure there are folks that know more about your particular engine and perhaps they will respond.

Bruce Clarkson

Re: risers and manifolds temp

no concern at all one riser always runs a little hotter.

Re: risers and manifolds temp

It's very common for the port side on Mercs to run a little hotter. As mentioned, it's just the way things are plumbed. The ability to keep your hand on it is a good thing. Do you have any steam coming out the port exhaust? If so, it could be a water flow restriction. If not, you're probably fine.

Re: risers and manifolds temp

and if your driveway slopes the other way, the starboard side runs hotter. it's gravity and water taking the path of least resistance.

Re: risers and manifolds temp

thanks for the info!