Rebuild 575 SCI's and add closed cooling system
03-22-2014, 07:34 PM
#1
I hate the winter!!
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Rebuild 575 SCI's and add closed cooling system
I am currently nearing completion of rebuilding a pair of 575 SCI's. These engines are used in salt water. I last rebuilt these engines 5 years ago. At that time, the water passages in the intake manifolds were nearly rotted through. I ordered new Weiand intakes. I had the new intakes ceramic coated hoping the coating would help the water passages from rotting out. As you can see from the first picture, although the coating may have helped, it didnt stop the inevitable. The passages rotted through again, sending salt water into the oil pan, eating up the bearings. Luckily, it was caught before they failed completely. Rather than replacing expensive intakes again. I choose to attempt to weld up the water passages and have the intakes flat milled. The next picture shows the repaired intakes. This will be the last time these engines will destroy expensive parts due to salt.
The only guaranteed salt solution is to install closed cooling on these engines. The problem... no kit exists.So, I decided to make up the kit myself. Due to the location of the blower snout, mounting the exchanger looked like the most difficult part. I ordered heat exchangers from Monitor Products. Got factory Mercury closed cooling t-stat housings from Bam. Then went to work with steel and my tig welder to fabricate a way to mount the heat exchanger. I had to drill and tap additional holes in the intake to mount the t-stat housing. I also had to use a spacer between the intake and t-stat housing to solve clearance issues. It took a long time to figure everything out, but the project seems to be working out well. I am currently waiting for more water hoses, so I have not completed running all of the hoses yet. This is what I have done so far. I am highly confident that this will work well keeping the engine temp in range, while putting an end to the rotting problems associated with salt water.
More pictures to come as I get further.
The only guaranteed salt solution is to install closed cooling on these engines. The problem... no kit exists.So, I decided to make up the kit myself. Due to the location of the blower snout, mounting the exchanger looked like the most difficult part. I ordered heat exchangers from Monitor Products. Got factory Mercury closed cooling t-stat housings from Bam. Then went to work with steel and my tig welder to fabricate a way to mount the heat exchanger. I had to drill and tap additional holes in the intake to mount the t-stat housing. I also had to use a spacer between the intake and t-stat housing to solve clearance issues. It took a long time to figure everything out, but the project seems to be working out well. I am currently waiting for more water hoses, so I have not completed running all of the hoses yet. This is what I have done so far. I am highly confident that this will work well keeping the engine temp in range, while putting an end to the rotting problems associated with salt water.
More pictures to come as I get further.
Last edited by Vinny P; 03-22-2014 at 08:47 PM.
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03-23-2014, 04:50 PM
#10
I hate the winter!!
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I cant wait to fire these engines up. It should be soon.
