Dumb question or good idea?
 

Ok here it is. I am thinking of removing the impeller in alpha drive and installing motor driven bravo raw water pump.
Will this work? Pros/cons?
Thanks in advance.

Are you trying to pick up the water from the drive, or are you going to use a separate external pickup?

I was thinking of pulling the water through the drive. The water is needed to cool the drive oil, correct?
Makes for easier service and reliabality and more potiental flow? I have the bravo pump and brackets in the shed.

Why do you want to do this? The belt driven bravo style pump does flow more, but the alpha pump should be adequate.

If you do this you need to take the impeller out of the drive. Also the hose from the transom to the thermostat housing is soft and will collapse under the suction from the belt driven pump and will need to be replaced with a reinforced type. This advice is from personal experience of doing this.

Question anwsered. Thank you mr. Marine.
Gary

Just thought of this...what are you going to put in the old pumps place? I don't think you just leave parts out without effecting something else?????

3pointstar

Leave pump just remove impeller.

but are there not moving parts within that housing that may utilize water for lubrication and/or cooling??

3pointstar

the top of the impeller housing is sealed with the impeller.you remove it and you will suck air in there when on plane as it would rise above the surface. both hoses. the one inside transom assy and the one from transom to thermo housing will collapse under suction. the bottom of impeller housing has 2 small holes for pump inlet-outlet. will cause flow restriction. every single thing about the alpha water path will not work as a suction input for a bravo or other engine mounted pump. the TRS has no water flowing thru upper housing. they handle lots more power than alphas. if you want to do this use a hull water pick up and put a shower on the alpha upper.

Many late model v6 alpha repowers are set up like this. Cruisers that were inboards or originally had through hull water pickups that were refit with late model powertrains. I know quite a few people with them and this is how the package came from merc

if you are essentially after pump serviceability what about just dumping the Alpha pump suplied water out through a through hull fitting and install a Bravo system with a transom mount pickup. That would allow you to retain drive cooling and you could verify its functioning visually. heck you could dump the water right on the drive for internal/external super drive shower :D

Glassdave, great idea. Thanks all for the responses.

just a thought but if you ever toast the Bravo pump impeller you might set up the sytem in a way that would allow you to switch back if need be to get ya home. I dont think I would go as far as any elaborate valving but maybe make the hose position and length conducive to the task, maybe keep a rubber end cap and extra hose clamp handy. Only reason I bring it up is my old Donzi was hard on pumps for some reason, possible option for ya :cool:

why can't we just put like a little wing on the side of the cav plate to throw water on the upper drive? there is soooo much there and it is going by so fast...maybe even a piece of metal tubing with a slight funnel shape to it and bent up and in.

boy am i brilliant!!! i just looked at pics of them and that is exactly what they are. i guess i should have invented it 30 years ago...

that ok, ive invented tons of sh! t thats already been invented :D . . . . . spent ten grand on this one lol . . . . I have others though. its a fun process :cool:


http://www.google.com/patents/US20110318946