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Alpha 1 Gen 2 cooling my 5.7 merc-gctid357732

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    Alpha 1 Gen 2 cooling my 5.7 merc-gctid357732

    As I posted in baffled by flyinghigh about my issues with high speed operation. Not wanting to highjack that thread. I was interested by 2350 bounty's reply to adding a second cooling pump. Can i connect a line to an existing through hull and T off to a new pump. If so what type of pump? can I fit a bravo one type to my existing setup? Like I said dont normally exceed 28 mph but should have the option, or am i better off to accept the limited speed and leave well enough alone. Thx.

    If you have the space, you can't beat the crankshaft pumps by Johnson or Jabsco.... or even Sherwood.

    No belt tension side load..... and they go for years and years without bearing replacement.

    You'll need a little distance between the crank pulley and any bulkhead or obstruction in order to fit it.

    Impeller removal is a piece of cake.

    Since the A drive sea water pump is pushing sea water, the hose ID is rather small for an adequate suction use.

    Crankshaft or belt driven pumps normally require a larger ID AND a "collapse" proof type suction hose.

    So.... you're pretty much limited to a seacock and thru hull style pick up.

    This is where you can "T" in the A drive pump.

    You will need a valve in order to isolate the thru hull when running on the garden hose/muffs.

    IOW, the thru hull will be shut off during the use of the garden hose/muffs.

    Been there/done this, and I can tell you that it works.

    This will very likely solve your top speed over-heating issue.

    BTW, there are two crankshaft pump volumes. The smaller volume pump should do just fine.... such as the F5b-9.

    The impeller for the smaller Johnson and Jabsco are the same, and are a very common impeller.

    Rick E. (aka RicardoMarine) Gresham, Oregon
    2850 Bounty Sedan Flybridge model
    Twin 280 HP 5.7's w/ Closed Cooling
    Volvo Penta DuoProp Drives
    Kohler 4 CZ Gen Set

    Please, no PMs. Ask your questions on forum.


      Great info!! thanks


        I assume the water exits thru the same exhaust?
        Phil, Vicky, Ashleigh & Sydney
        1998 3055 Ciera
        (yes, a 1998)
        Previous boat: 1993 3055
        Dream boat: 70' Azimut or Astondoa 72
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