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Message |
    
martanke
Member
Username: martanke
Post Number: 23
Registered: 06-2011
| | Posted on Tuesday, May 01, 2018 - 05:48 pm: | 
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I'm considering replacing the gear pump on my 1946 Chrysler Royal M8 with a Jabsco impeller pump that was offered as an alternative option. I believe the pump is called 3290-9001. Anyone has experience of this pump? Anyone has one for sale?
Thanks |
drrot
Senior Member
Username: drrot
Post Number: 240
Registered: 09-2008
| | Posted on Thursday, May 03, 2018 - 08:41 am: |
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One issue with the rubber impeller pumps is they recommend replacing the impeller every couple years. |
miro
Senior Member
Username: miro
Post Number: 970
Registered: 11-2001
| | Posted on Tuesday, May 08, 2018 - 06:19 pm: |
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The usual challenge with gear pumps are not the gear teeth, but the clearance between the end walls of the pump case and the side of the gear.
If this is sloppy, then the pump won't work well, and certainly won't draw the water up the 12 inches or so from the water inlet.
It should be straightforward to remove from the engine. I have found that a clearance of 5 to 10 thou works well.
Another issue is the grease that is used. Water pump grease is designed for these kinds of water pumps. It's very thick - almost like wax, but it will flow. A little will last a long time - I've got a 15 oz can that I've been using for 20 years.
And finally, when I start up the boat in the spring - I like to "wet its whistle" - that is get water into the engine water jacket and back into the pump. This helps clean out the schmutz ( a technical term for "crud")that has accumulated there over the winter.
If you treat your water pump well, it will last the life of the engine.
miro |
martanke
Member
Username: martanke
Post Number: 24
Registered: 06-2011
| | Posted on Thursday, May 24, 2018 - 07:24 am: |
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Thanks for replies. The pump works well. However I have converted the engine to fresh water cooling and I'm using the gear pump for the closed system and an external belt driven impeller pump for the raw water side. I probably should have done it the other way around. Reason being that the gear pump is cooled and lubricated by the water it's pumping and it is supposed to drip a bit to ensure sufficient cooling.
After repacking the pump with the correct grease I believe I have it down to minimal drip level. But even that is more antifreeze in the bilge than I would like to see. Anyways, I've now found the Jabsco pump I was looking for and will give it a go. |
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