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What is the value of this motor?

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  • #46
    Seriously?!? Is that new or used?

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    • #47
      Re: The allowable RPMs for the prop, here's the pic of the engine label again (also shown on 1st page of this thread). Since this prop is most likely paired with the motor (assembled as a package), I think the W.O.T. (Wide Open Throttle) specs should be followed.

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      • #48
        For this post, when I say 'engine', I'm referring to the ICE. 'Motor' is the electric...

        That maximum RPM is the engine RPM. When setting a boat up from new, or with a new engine, we test run at Wide open and see what revs the engine gets to. If it's higher than the spec, we use a higher pitch prop (more forward movement per revolution), if too low, we put a lower pitch prop on. The aim is to get the engine to revs at or near the top of the limit. If you have too much pitch, that doesn't just affect the top end, it overloaded the motor through the whole rev range.

        The drive with this engine would have been 1.98:1 (standard ratio supplied with the 120hp engine), so the prop speed would be almost half, about 2,000rpm...

        Set up the electric motor, then take it out and see what RPM you get from the motor. I would aim to have it run around 5,000 to 5,500rpm at full 'throttle' (that's motor revs, not prop revs)... If it is too low, use a lower pitch prop (allow the motor to spin a bit quicker). With a petrol engine, the 'rule of thumb' is that each 2" of pitch will change the engine speed around 400rpm. But as I have no idea of the torque characteristics of the electric motor you're planning on using, that may work, or it may be out the window. You're blazing new ground here.

        You could also utilize the water pump in the drive to cool a heat exchanger for the motor's oil...

        The other consideration is how you deal with forward, neutral and reverse. I'm not sure how it's done in a car, but I know that synchronous AC motors are quite happy to spin 'backwards' . You can't do this with a drive. You need to have the motor spin only one way (CW looking at the 'pulley end'). You may want to bring the motor to very close to a stop as the drive comes out of gear, this should allow you to do away with any sort of shift interrupter. But you'll need to have the motor spinning, even if very slowly, as you go into gear (forward or reverse)...

        Cheers,

        Chris.......
        xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
        The world takes on a whole new perspective when viewed from 100’ below.
        1972 Bertram ‘Bahia Mar’ 20
        2006 Mercruiser 4.3MPI (0W617679) w/Alpha One Gen II (0W829301)
        (Original - 1972 '165' In-line 6. Previous - 1994 4.3LX)


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        • #49
          What do you mean by “pulley end”? Looking at the prop from outside the boat (facing the bow) or inside (facing the stern)? And what is this “pulley” you speak of? :-D

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          • #50
            Originally posted by Luposian View Post
            What do you mean by “pulley end”? Looking at the prop from outside the boat (facing the bow) or inside (facing the stern)? And what is this “pulley” you speak of? :-D
            the input side of the drive. the motor has the pulley.

            regarding your conversion, you really need to look at smasterson2 thread https://forums.iboats.com/forum/boat...o-all-electric
            Cheesehead boating the Gulf Coast of FLA 27.51° N, 82.53° W

            1988 Cruisers Rogue 2420 -VP 290 DP now powered by custom 468 - https://forums.iboats.com/forum/owner...988-rogue-2420

            Past Boats
            1970 Wooster Hellion - Merc 9.8
            2002 SeaRay 190BR - 5.0 - A1G2 - "Cheeseheads in Paradise"
            1984 Avanti 170DLI -3.0 stringer- "Ship Happens"

            What’s behind you doesn’t matter.Enzo Ferrari

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            • #51
              Originally posted by Luposian View Post
              What do you mean by “pulley end”? Looking at the prop from outside the boat (facing the bow) or inside (facing the stern)? And what is this “pulley” you speak of? :-D
              I was trying to use a petrol engine analogy. Looks like I failed spectacularly . The 'pulley end' I was referring to was where the pulleys on a petrol engine would have been. The 'front' of the engine. So, let me try again.

              Electric motor installed. You're standing in the boat, looking at the motor, facing aft. The end of the motor shaft you would see (if it wasn't sealed up) needs to turn CW....

              Chris......

              Very crude attempt to make a pretty picture....

              Click image for larger version

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              xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
              The world takes on a whole new perspective when viewed from 100’ below.
              1972 Bertram ‘Bahia Mar’ 20
              2006 Mercruiser 4.3MPI (0W617679) w/Alpha One Gen II (0W829301)
              (Original - 1972 '165' In-line 6. Previous - 1994 4.3LX)


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              • #52
                NOW it all makes sense! :-D Thanks for the clarification, achris!

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                • #53
                  Based on the rust/corrosion I'm finding, as I pick apart this engine, trying to get access (note the word TRYING) to the two front (facing the stern drive) mounting bolts, I'm 99.9% certain this engine is toast. No matter, in that regard, but I still need it OUT! :-D

                  I don't have access straight down to them, so is there a socket extention or tool that can provide leverage at a weird crooked angle? My mind is visualizing something like a hand crank drill. The one with a ball-like top and you crank it around like you're churning butter, not like a hand crnk mixer. Weird analogy, but... there it is. :-D

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                  • #54
                    Ok, I think I just found it. This what I need? Not sure if I should trust stuff from Harbor Freight (seems most of it is cheap junk), but at least I think I found the tool I need:

                    https://www.harborfreight.com/9-pc-w...set-67971.html

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                    • #55
                      Sign up today
                      You need to start referring to locations of parts you are trying to describe by their location on the engine with reference to the boat, not to what direction you are facing.. It's very confusing.

                      The front of the engine has the water pump and alternator on it. Doesn't matter if your standing on your head, it's still the front of the engine.. distributor and starter motor are on the starboard side and the carburettor is on the port side... The flywheel is at the rear of the engine.

                      The tool you're looking for is a wobble or uni joint for a socket...I assume you're trying to get to the engine rear mount bolts... You'll need a 3/4" socket...

                      Chris...
                      xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
                      The world takes on a whole new perspective when viewed from 100’ below.
                      1972 Bertram ‘Bahia Mar’ 20
                      2006 Mercruiser 4.3MPI (0W617679) w/Alpha One Gen II (0W829301)
                      (Original - 1972 '165' In-line 6. Previous - 1994 4.3LX)


                      Comment

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