440 fresh water cooled engine temp help

[JDavis]

Just wondering if someone might have any thoughts on an issue I'm having. I have 440 gassers, fresh water cooled engines. I'm running 160 degrees on my port and 195-200 on starboard. I've replaced the thermostat on starboard engine and tried running it without the thermostat. I've also replaced the circulating pump in the engine and still have high temps (195-200). I'm pumping raw water pretty good since I can see it coming out the exhaust port so I'm assuming my raw weter pump is working ok. I can see the circulation on the other engine's fresh water tank but not on the one I just replaced the water pump on. Any ideas from you guys????? I hope someone has an idea. I'm desperate to go fishing.
Thanks.
John Davis

[RussP]

I would think your heat exchanger is clogged. I just cleaned mine with muritac acid and was amazed at how much crap came out. I removed the coil wire and the raw water inlet hose and hooked up a 4' length of hose to stick in a bucket of 50/50 acid mixture. Turned the motor over till the raw water pumt pulled the mixture through. Reattached the water hose and coil wire and fired her up. I don't know if the residue was the acid or built up crap from the exchanger but I run @ 160* with no steam. Crusader 454's soon to be yanked for diesels.
Good luck,
RussP

[Rawleigh]

Just a thought but are you sure it was a marine circulating pump that you put in with the bronze impeller. In a pinch I put an automobile on in my boat because a marine one wasn't available, and it always ran hotter until I swapped it out when the new part came in. The auto ones with the stamped steel impeller don't move nearly the water that the marine ones do. My Chryslers came with 140 degree thermostats. i have replaced one with a 160. Is the volume of raw water the same on both sides?

[JDavis]

Russ, thanks. I'll recheck those exchangers and make sure I'm not clogged.
Rawleigh, I did take out the circulating pump and it did have the bronze impeller. The one I put back in had the steel impeller but the blades were a bit bigger and had a 90 degree at the end of each blade. Looks like it would push even more water but maybe not. I also lucked out that the engine was the right rotation for the blades. I also seem to be pumping the same amount of raw water on both sides. Mine also came with the 142 degree thermostat and I also replaced with the 160. I'm hoping that perhaps the heat exchanger is clogged. That's about the only thing I haven't gone through. I'm keeping my fingers crossed.
Thanks.
John

[Rawleigh]

John: Put a marine style circ pump back in it. I had the same problem. It seems like the auto one ought to flow more, but it doesn't . The solid back on the marine impeller really makes a difference. My cooling problems cleared up when I put a marine one back in my 440's. They are expensive, but they work.

[Carl]

It don't take much to make the 440's run warm.

From my 12 years with the engines I have found:

-Old raw water impellors will not pump enough water.
-Worn cam in the raw water pump will not pump enough water.
-Clogged anything will not pump enough water.
*Check for debris in oil and tranny coolers.
*Heat exchanged clogged.
*Check your risers and hoses going to them, a little restriction will not
pump enough water.
-A loose belt driving the raw water pump, will not pump enough water.
-Check your engines timing. Being off a few degrees will make engines run Hot.

Looking at water coming out the exhaust ports only means your pumping water. Whether you are pumping enough to keep the engine cool is another story.