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270 crusader running warm

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44' gibson

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270 crusader 1983 starboard motor raw water cooled, block getting warm. I have changed thermostat (142 degree), rebuilt sea water pump, replaced circlulating pump, checked flow through sea water pump 12 gallons per minute at 1200rpm, Port pumps the same. Checked transmision cooler flow through it is the same. Block is reaching temps in upper 150's and lower 160's with IR gun gauge is reading 170. exhuast is cool manifolds and elbow below 100, measured water coming out of exgaust and both motors pumping the same, but other motor block chaecks 110 to 120? I'm stumped
 
That's a whole lot more flow than what is spec'ed for those pumps. may want to assess the quality of the water provided by the pump...any air will severely impact the cooling provided.

What did "rebuilt sea water pump" entail?

The other thing to consider is your block is 30 years old...may have a bit of crud in the water jacket....
 
Sea water rebuild consisted of impeller, cam, bushing, front cover, bearing, seal kit, snap rings, everyting but shaft. This motor now pumps same as the port side motor when checked with a bucket and stop watch straight out of the pump. Used a clear hose from top of transmission cooler ,and thermostat housing and didn't see any air. I pulled the plugs out of the block and ran engine for a bit while fishing a wire up in the cavaity did get some stilt but ran pretty hard and clean out of there. But it does act like the water isn't flowing through the block, heads and back to the intake correctly. I just don't know where to look for the blockage. Has neve ran in salt water.
 
Look for an air leak before the raw water pump. Even a tiny amount of air sucked in from a loose hose or a strainer gasket leak will cause that. I've been down that road once!

Jeff
 
Frankly, there is no easy way to look for vacuum leaks--pressure is easy; just spray soapy water and look for bubbles.

I'd start by examining every connection very carefully, especially the strainer lid gasket. That's where mine was leaking air IN.

Jeff
 
I too have had that problem with the cork gasket in the lid of our strainers. Insult was that the perko gasket is $14.00. Bought a nice roll of cork gasket material for $6 and made a few spares plus
 
Found the source of air entering the raw water system, there was a hole in the hose from the V-drive to the sea water pump, where it crossed under the oil pan.
Thanks to all on this forum who gave their advice, I just wish Iwould have joined earlier it could have saved me several hundred dollars.
 
44' gibson said:
270 crusader 1983 starboard motor raw water cooled, block getting warm. I have changed thermostat (142 degree), rebuilt sea water pump, replaced circlulating pump, checked flow through sea water pump 12 gallons per minute at 1200rpm, Port pumps the same. Checked transmision cooler flow through it is the same. Block is reaching temps in upper 150's and lower 160's with IR gun gauge is reading 170. exhuast is cool manifolds and elbow below 100, measured water coming out of exgaust and both motors pumping the same, but other motor block chaecks 110 to 120? I'm stumped
Click to expand...

This is a problem also......
 
gibson,

I was thinking the same thing as Chris. With 142 degree thermostats (in both engines?) I would expect them both to run at about 145-150, maybe higher at high rpms. You didn't say what the temp was after finding and correcting the air leak.
 
I'm sorry the 110 to 120 temps on Port motor was on the intake, not near the water jacket, at the same time the starboard was reading 150 - 160 in the same locations on it's intake. Starboard at intake by sending unit was 150 and on port was 145. Port also has new 142 thrermostat. Port motor end of heads were 140, starboard was 155-160 After I found the air leak and replaced the hose ( of course on this trip I didn't bring IR Gun ) intakes felt the same, much cooler. I think I found the issue, but I will take the IR gun this weekend and report back temp comparisons.
Agian Thanks for all the great feedback, and advice on this Forum
 
I went to the boat over the weekend, and took the IR gun with me. The temps between the Starboard engine that was running warm, and the Port engine, after replacing the hose with hole are very similar, and I think in a satisfactory range for raw water with 142 thermostats.
If any of these temps look out of range to you guys please reply.
Idiling at dock for 30 minutes. Oil filter temps Port 135 Starboard 139, Intake at temp sending unit Port 143, Starboard 147, the heads shot on the ends both front and back, The Port engine ranged from 139 to 146, Starboard ranged from 135 to 150, Exhuast Port was 84 and 80 on manifolds and 78 and 88 on elbows. Ehuast on starboard was 73 and 80 on manifolds, and 81 and 84 at elbows.
Another issue is my gauges are still showing a 15 degree diiference, but I will check these in the spring, by swaping senders.
I also need to check temps under a load but that will have to wait until spring, It is time to winterize here in Ky.
 
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