Overheat

"350cid 270hp 1989 Crusader FW

"350cid 270hp 1989 Crusader FWC. Just replaced risers, elbows, and thermostat (160) removed and flushed manifolds. Gauge on the dash says 160. Used IR temp gun to get following measurements, most taken on the hoses. Just in case the drawing doesn't show up too good. Port manifold 213, starboard 195. Top Center of the heat exchanger 192. Should I worry if the temp gauge (and the thermostat housing) reads 160? Just a little concerned that the heat exchanger is hitting 192. Any Ideas????
temps

"Al:

did you take them at c

"Al:

did you take them at cruise or idle?

Overall, they don't look tood bad. The 95 going to the circulating pump is an assumed error (should be going to starboard elbow(?)

the 144 on the hoses coming out of the 160 t-stat don't make sense (other than measurement error).

the HX will be hotter than the tstat as it is picking up the heat from the manifolds.

You said you flushed the manifolds...did you do the block too? Also, did you pull the caps on the HX and swab it out, too? finally, what's the condition of the raw water pump?"

"Al, for some reason, your hos

"Al, for some reason, your hose measurements are pretty much all messed up. I'm not believing any of them. Are you sure the raw water output hoses out of the HE didn't get mixed up with the coolant hoses headed for the exh mans? They look to be traded..165 out the of thermo at cruise is perfect. 192 at the input to the HE is also very close to normal."

"I checked the hoses and all a

"I checked the hoses and all are in the right place. I'm going to take a few more temp readings on the fittings where they connect for a little better accuracy. I did flush the engine as well. Never did have a overheat problem but the risers on my port engine clogged up and I did have a problem there. Just decided to change to ones on the other engine before it bit me offshore somewhere. Motor runs good and the dash temp is 160 on the money. I was just a little concerned about the 213 on the inboard manifold. But like everything before it breaks, engine is running good right now. I'll keep an eye on it!!"

"This temperature thing puzzle

"This temperature thing puzzles me in one area....I took our boat out this weekend for a few hours to make sure she is in running shape and all was good. Sea temp around 55. Temps were RARELY 140 in fact most of the time they were nearer 125. Shouldn't the termostats keep the temps higher? During the warmer weather we hit the 160 mark but would the colder sea water keep the FWC engines this low for any other reason?

I HOPE I am not hijacking this thread....JUST since it is an active cooling issue, I asked this question here....AL"

"Al:

The t-stats shouild ke

"Al:

The t-stats shouild keep the motor the same temperature regardless of the air or water temperature. I suspect your's aren't closing tightly enough, or they're stuck way open.

Jeff"

"CaptAl:

You may be experie

"CaptAl:

You may be experiencing some 'measurement errors' with the gun. Most have a 'spot size' and you need to be consistent with the distance you measure from. Another concern would be a direct comparison between a painted surface to a rubber hose...

One item I seen a few times is "background noise"...easiest way to visualize it is to think of taking a picture with your back to the sun and then looking into the sun. the object hasn't changed but what the camera sees is different.

On the manifolds, make sure you measure away from the exhaust ports as they will get quite hot, especially when running."