Riser temp

[Mgtdguy]

My 34' Californian has 3208 NA's. The port exhaust risers run 98F at 1700RPM and the SB engine risers run at 78F at 1700RPM. Heat exchanger temps are both 120F. This condition stays like this even after many hours of running. The raw water pumps were new just over a year and about 150 hours ago as we're the risers and heat exchanger cleaning. I am not sure if this is a problem or not but it seems like they should be closer in temp. I cruise at that rpm most of the time and take my heat gun to the engines every hour or so while underway. Have not noticed any temps above 185 on the exhaust manifolds.

Does the difference of 20F in the riser temp indicate a problem? If so, what?

 

[Shoalwaters]

The temperatures should be fairly similar. Is this a new problem, or has there been a difference in temps since the new pumps and H/E cleaning? Sounds like there is significantly more water flowing through the stbd exhaust riser than the port one. The question is why? I would be inclined to check the raw water pump impellers first. Are the sea strainers and through-hulls clear?

 

[capt jerry]

may be that engine is working harder than th e other one???

 

[Mgtdguy]

They both ran about the same 75-78F until the return trip from the Canadian Gulf islands which was a 11 hour run at 1700RPM. The last few hours of that trip was when I noticed the port engine risers running hotter than the starboard risers. The engine temp gauge remained at the same level and the riser temps did not get any hotter so I continued on home. The raw water impeller is a good place to start. Because the exhaust exits are partially submerged it is difficult to determine if one engine is pumping out more than the other. Thanks-Steve

 

[JAT]

Any possibility you have a sticky thermostat?

 

[FF]

Don't worry , be happy!