broncopower
Cadet
- Joined
- Aug 20, 2012
- Messages
- 10
Hi All,
I have a 1982 Chris Craft Catalina with a 1990-93 GM Tonawanda 1/2 FWC engine. I forget the exact year, and there is no hour meter. Last summer, the engine overheated in Baltimore harbor, and I idled back to my dock with a strong thunderstorm approaching. There was a lot of steam, no water flow out the exhaust, and very hot manifolds & risers. I replaced the manifolds & risers, having to deal with striped & rusted bolts from the brackish water. I also replaced the impeller, thermostat, sea ****, and had the heat-exchanger re-welded due to an internal leak. I also replaced the spark plugs and tested compression, which looked good. I forget the exact numbers, but they were all in the same range.
Upon start up this summer, all seemed well. I replaced the gas & added some seafoam. Water flow out the exhaust was good, and no white steam! I headed out of the dock, and the engine overheated, so I idled back to the dock again! The heat exchanger was empty of anti-freeze, with no apparent leaks. The next week, I filled the heat exchanger with coolant, and changed the engine oil. The oil looked good, and I didn't notice any milky color or funky smell. I planned to remove the spark plugs to look for coolant, but they are a PITA to get to. I started the engine, and it ran smooth without smoke. However, I noticed green clouds out of the exhaust, and could scoop up hand fulls of antifreeze coming out of the exhaust. I turned the engine off, and noticed a considerable loss of antifreeze in the heat exchanger.
Thus, I figured there must be an internal leak in the riser gasket. I foolishly over-torqued the riser bolts originally, and the stud broke off in the riser. I was able to remove the riser, but I have to use some left-hand drill bits to remove the broken stud, which is flush with the riser. I'm hoping I won't have to use "easy-outs":facepalm: The riser gasket split apart, so I will have to scrape it off the manifold & riser surfaces before installing new gaskets and bolts. I was surprised that the gasket is restricted, but I ordered the gasket kit with the manifolds & risers from a marine shop, so they must have been the right type, right?
Please give me any advise you can think of, and take a look at the attached picture of my cooling system re-assembly. I did not take a picture of the engine before removing the risers/manifolds originally, so I want to make sure the correct hoses are leading into the manifolds/risers. I can not find a 1/2 FWC diagram online.
Thanks
I have a 1982 Chris Craft Catalina with a 1990-93 GM Tonawanda 1/2 FWC engine. I forget the exact year, and there is no hour meter. Last summer, the engine overheated in Baltimore harbor, and I idled back to my dock with a strong thunderstorm approaching. There was a lot of steam, no water flow out the exhaust, and very hot manifolds & risers. I replaced the manifolds & risers, having to deal with striped & rusted bolts from the brackish water. I also replaced the impeller, thermostat, sea ****, and had the heat-exchanger re-welded due to an internal leak. I also replaced the spark plugs and tested compression, which looked good. I forget the exact numbers, but they were all in the same range.
Upon start up this summer, all seemed well. I replaced the gas & added some seafoam. Water flow out the exhaust was good, and no white steam! I headed out of the dock, and the engine overheated, so I idled back to the dock again! The heat exchanger was empty of anti-freeze, with no apparent leaks. The next week, I filled the heat exchanger with coolant, and changed the engine oil. The oil looked good, and I didn't notice any milky color or funky smell. I planned to remove the spark plugs to look for coolant, but they are a PITA to get to. I started the engine, and it ran smooth without smoke. However, I noticed green clouds out of the exhaust, and could scoop up hand fulls of antifreeze coming out of the exhaust. I turned the engine off, and noticed a considerable loss of antifreeze in the heat exchanger.
Thus, I figured there must be an internal leak in the riser gasket. I foolishly over-torqued the riser bolts originally, and the stud broke off in the riser. I was able to remove the riser, but I have to use some left-hand drill bits to remove the broken stud, which is flush with the riser. I'm hoping I won't have to use "easy-outs":facepalm: The riser gasket split apart, so I will have to scrape it off the manifold & riser surfaces before installing new gaskets and bolts. I was surprised that the gasket is restricted, but I ordered the gasket kit with the manifolds & risers from a marine shop, so they must have been the right type, right?
Please give me any advise you can think of, and take a look at the attached picture of my cooling system re-assembly. I did not take a picture of the engine before removing the risers/manifolds originally, so I want to make sure the correct hoses are leading into the manifolds/risers. I can not find a 1/2 FWC diagram online.
Thanks
