MD7A block zincs

[John MacArthur]

Has anyone with a MD7A/B ever found a zinc in the engine block? I'm not talking about the one in the mixer muffler. A search for "zincs" brings up several "no zincs that I'm aware of...", but I'm wondering if anyone has done an exhaustive search. It seems that an engine made for raw-water cooling should have a zinc in it somewhere.



jmac@laplaza.org

[Bill DeCamp]

Has anyone with a MD7A/B ever found a zinc in the engine block? I'm not talking about the one in the mixer muffler. A search for "zincs" brings up several "no zincs that I'm aware of...", but I'm wondering if anyone has done an exhaustive search. It seems that an engine made for raw-water cooling should have a zinc in it somewhere.

;I went thru this same drill after we took delivery of our 83 CD28 in Sept 82. I had changed out hundreds of zinc's in my 22 years of active duty in the US Navy.So when we hauled out a few years later I of course expected that along with the perry nut zinc on the end of the propeller shaft there should be pencil zincs somewhere on the engine. I couldn't find any and the Volvo repair facility mechanics where quick to tell me that the only zinc was the perry nut zinc, so when ever it has worn away more than 50% I have replaced it and after seventeen some years of ownership the engine shows no ill effects so all I can say is Volvo must have determined that the zinc on the end of the shaft was all that was needed.



tocoiriverrats@aol.ccom

[John MacArthur]

Has anyone with a MD7A/B ever found a zinc in the engine block? I'm not talking about the one in the mixer muffler. A search for "zincs" brings up several "no zincs that I'm aware of...", but I'm wondering if anyone has done an exhaustive search. It seems that an engine made for raw-water cooling should have a zinc in it somewhere.

;I went thru this same drill after we took delivery of our 83 CD28 in Sept 82. I had changed out hundreds of zinc's in my 22 years of active duty in the US Navy.So when we hauled out a few years later I of course expected that along with the perry nut zinc on the end of the propeller shaft there should be pencil zincs somewhere on the engine. I couldn't find any and the Volvo repair facility mechanics where quick to tell me that the only zinc was the perry nut zinc, so when ever it has worn away more than 50% I have replaced it and after seventeen some years of ownership the engine shows no ill effects so all I can say is Volvo must have determined that the zinc on the end of the shaft was all that was needed.

Thanks for that, Bill. On my boat there is a pencil zinc in the water-lift muffler, as well as a shaft zinc. I guess I'll stop worrying.



jmac@laplaza.org

[John Hunter]

Just for your information, my MD7A which has a Sendure jacket water heat exchanger, has a pencil zinc in the raw water side of the heat exchanger.



jhunter@seaworthysys.com