Prop advice for repowered 1994/95 Caravelle legend 2000 BR

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  • Prop advice for repowered 1994/95 Caravelle legend 2000 BR

    Hello Ken, this boat originally had a 5.0LX Mercruiser with Alpha 1 gen 2 drive. She was turning a 13 3/4 x 21P, Merc 48 78122 A40 21P prop. Not even sure if this is stock, but from what I can find on the web, it`s what came with this power set for the boat. The boat now has a 350 V8 reman, non vortec roller cam engine with same outdrive. somewhere in between 230 and 270HP I do not believe this reman is 270 as I was told,
    I am wanting to go to 4 blade and am curious about the TurningPoint prop for their blade design characteristic.
    the reason> during the initial engine run it, the seas were rough for this 20ft runabout. Trimmed all the way in to plane in the crap waters took a good bit of effort as the bow was still high. Feels like I could use better grip. Now she would plane out with a lot of throttle, and then had to back out bc of the rough seas. so not really a good day to break in an engine.
    I like to run the rivers here with glass to mild chop, but heading out to the bays and ICW can get nasty. IMHO this is not really a rough water craft.

    I wont know max rpm, typically 4800 for this engine, book says 4400-4600 for the 5.0, for quite a while. mostly time and weather restricted.
    I don`t like the way this boat comes out with this 3 blade. I`m ok with a speed loss, as I`m sure even with a 4 blade it will move out good enough.
    A few boating friends have recommended the 4 blade, Better grip, better handling, and stern lift I believe would be better than whats on there.
    Asking for your guidance please?
    Thank you, Andy
    Last edited by SeaDawg3; 08-12-2020, 06:23 PM.

  • #2
    I'll take a guess that you have a 1.47 gear ratio. not 100% on that as we are not sure on the stock motor, and I can't seem to find any info on that boat. (got a picture of it?)
    I would suggest a Powertech SFS4, pitch will depend on speed.
    17 would be high 40's, 18 would be low 50's (if you could turn them 4800)
    So it kinda depends on how you load the boat most of the time, and what speed we are expecting the boat to run.
    Also, if your planning on loading the boat up with quite a few people and pulling wakeboarders all day, we will probably want a lower pitch then if you and your wife are just cruising around with 1/2 tank of fuel most of the time.

    Ken Reeves
    [email protected]
    941-735-5808

    Comment


    • #3
      Originally posted by ken2 View Post
      I'll take a guess that you have a 1.47 gear ratio. not 100% on that as we are not sure on the stock motor, and I can't seem to find any info on that boat. (got a picture of it?)
      I would suggest a Powertech SFS4, pitch will depend on speed.
      17 would be high 40's, 18 would be low 50's (if you could turn them 4800)
      So it kinda depends on how you load the boat most of the time, and what speed we are expecting the boat to run.
      Also, if your planning on loading the boat up with quite a few people and pulling wakeboarders all day, we will probably want a lower pitch then if you and your wife are just cruising around with 1/2 tank of fuel most of the time.
      Yes, I have the 1.50 ratio Alpha One Gen 2. This 350 non vortec roller cam engine was listed at 270HP, but I doubt that. I`ll have to say 250 at best.

      most occasions would be 2 people and 2-3 dogs, some of the time it would just be myself. Boat weighs 2550 dry, holds 30 gallons of fuel, 2 batteries are on board, Anchor, rope, gear, fishing gear when fishing. We reconfigured the interior for simplicity. new gunwale, engine hatch, typical box boat seats. So where I removed a lot of weight, I also added weight with slightly thicker wood in the rebuild. I would say it even`s out, but she def feels a bit heavy with this 3 blade.
      I do know the previous owner pulled tubers with that 13 3/4 x 21 with the original 5.0LX mercruiser engine.

      true, not much info on the caravelle legends bow riders, their popularity comes from the Interceptor Line up.

      1994 Caravelle Boats Legend 2000 Bowrider
      This Caravelle inboard/outboard runabout has a fiberglass hull, is 19.58 feet long and 92 inches wide at the widest point. The boat weighs approximately 2550 pounds with an empty fuel tank and without any gear or passengers.

      in your suggestion can you explain (educate me) on the 4' drop in pitch between the stock 21P and the 4 blade 17?


      I should have provided more data, I should run the boat for more break in time on the River where it is smooth to see how it performs coming up on plane. My original inquiry was bc the boat was not performing as it should in the rough seas. Finding out more that these Caravelle`s are horrible in the rough.

      Thank you, Andy V
      Attached Files

      Comment


      • #4
        They don't make a 1.5 Alpha 1 Gen 2. The Bravo 1 is often 1.5
        Mercruiser Alpha 1 Gen 2 (1991 & Newer)
        3 Liter 130 1.94
        4.3 Liter 175 1.81
        5.0 Liter 230 1.61
        5.7 Liter 260 1.47
        The correct pitch is determined by the expected slip ratio of the prop we are talking about, that the actual speed of the boat.
        I expect about 8-10% slip with a Powertech SFS4. (lots of other props to choose from, but you ask about a 4 blade and that is one of my favorites)
        Your shooting for 4800 RPM.
        now the missing link is , "How fast does your boat go on GPS, with the boat loaded up like you actually plan to run it?"

        Since you haven't ran it yet, Its a guess.
        I'd start with letting us know how you plan to load it.
        Are you loading up with a bunch of people and gear and stuff and pulling tubes and watersports all day.
        are you just cruising around with a couple people in the boat
        are you trying to see how fast you can make the boat go and only load light?

        Just looking at the boat, I'm gonna say 50 MPH would be about what i'd expect. Hence my suggestion for 17 or 18 pitch

        Ken Reeves
        [email protected]
        941-735-5808

        Comment


        • #5
          Originally posted by ken2 View Post
          They don't make a 1.5 Alpha 1 Gen 2. The Bravo 1 is often 1.5
          Mercruiser Alpha 1 Gen 2 (1991 & Newer)
          3 Liter 130 1.94
          4.3 Liter 175 1.81
          5.0 Liter 230 1.61
          5.7 Liter 260 1.47
          The correct pitch is determined by the expected slip ratio of the prop we are talking about, that the actual speed of the boat.
          I expect about 8-10% slip with a Powertech SFS4. (lots of other props to choose from, but you ask about a 4 blade and that is one of my favorites)
          Your shooting for 4800 RPM.
          now the missing link is , "How fast does your boat go on GPS, with the boat loaded up like you actually plan to run it?"

          Since you haven't ran it yet, Its a guess.
          I'd start with letting us know how you plan to load it.
          Are you loading up with a bunch of people and gear and stuff and pulling tubes and watersports all day.
          are you just cruising around with a couple people in the boat
          are you trying to see how fast you can make the boat go and only load light?

          Just looking at the boat, I'm gonna say 50 MPH would be about what i'd expect. Hence my suggestion for 17 or 18 pitch
          most occasions would be 2 people and 2-3 dogs, some of the time it would just be myself
          light load ie: food, drink, normal gear , no tubes no skiers, cruising around. top speed is whatever it turns out to be. I`m sure the boat has potential if dialed in for max speed, the wife and dogs won`t appreciate that! lol

          I can only tell you what my outdrive has on it as well as my service manuals and owners manual.
          Attached Files

          Comment


          • #6
            Originally posted by ken2
            Well if its 1.5, then I'd be choosing between 18 or 19.
            Hi Ken, I understand the difference in ratio`s between the years. I`ve addressed this with one of my co workers, a Marine Mechanic, that suggested it was an early gear case perhaps with remote resevoir. It def is a GEN 2 unit. if I could decifer the unit serial number that might tell me more. we both think the engine and drive must of come from another boat. I`ll get some run time on this current prop and get some data collected.
            Thank you.

            Comment


            • #7
              I actually deleted my post, as the pitch would still be the same choice, 1.47 vs 1.5 is basically nothing anyways.
              so I'd still be deciding between a 17 or 18 pitch.
              I wish they would put the gear ratio on the side of all the bravo and alpha drives so we know which one they have. Hard when your dealing with boats that may have been repowered, or had the lower units replaced and then you find out something is different about them.

              Earlier today, about the time I was answering your post, I had a guy with a Bravo 1 with a 1.65 gear ratio, which is just a little odd as well.

              But the SFS4 would still be my first choice. If you expect high 40's, go 17, if you expect low 50's, go 18.
              Or if you have some off the wall speed your expecting out of the boat, you can choose pitch based on that.

              Ken Reeves
              [email protected]
              941-735-5808

              Comment


              • #8
                a little bit of info, wish I could remember the exact speed at what rpm but I still have a ways to go with break in. We did the normal routine, vary rpms, load the engine, stepped into the throttle to feel the secondarys and fill the rear float bowl in the Holley carb. I only tapped it to a quick 4100-4200, but most of the hour run time was idle to plane off and vary r`s between 2400 through 3200.
                the prop on right now is the 13 3/4 x 21 3 blade. The boat likes 3100-3200 rpms, feels real comfortable cruising in the mid 30s. Garmin GPS chartplotter, no stock speedo in this boat. pretty much was a good ride this time, between mid 20`s to mid 30`s. we had a max speed recorded of 40.0, boat def had more. Did not note the exact RPMs it def was not maxxed out. the new engine is loosening up.
                A boat buddy is loaning me some props they pulled off other Alpha1 drives. have to wait and see what they are, I believe they are 3 and 4 blade.

                conditions were super smooth waters, maybe 28-27 gallons of fuel, gear and 2 people.

                Comment


                • #9
                  a little update, after a minor set back with an engine seal, the boat was ready for another run. My neighbor and I tried a 14x19 4 blade. what a night and day difference from the 13/3/4 x 21.
                  as suspected the boat planned off easier, quick to desired speed, and changing speeds was effortless. midrange accelleration very good. approx 3500 rpm was 40mph, and cracking the throttle to over 4K rpm was 46.9.
                  still breaking in the engine and she is loosening up...
                  conditions were 10-15pmh winds, med chop, 2 people, 30 gallons of fuel and normal gear.

                  Comment


                  • #10
                    sounds like an improvement !
                    anxious to see how it runs wide open.
                    What brand/model 19 pitch are you running?

                    Ken Reeves
                    [email protected]
                    941-735-5808

                    Comment


                    • #11
                      Originally posted by ken2 View Post
                      sounds like an improvement !
                      anxious to see how it runs wide open.
                      What brand/model 19 pitch are you running?
                      This test prop is an aluminum 4 blade. I see its vented. Turning Point Hustler
                      will be awhile yet be I let her rip...

                      the rivers we run have unseen obstacles, even tho we try to stay within the channels and deepest part of the water. boaters around here are mostly use alum vs stainless. Now once out through the bay and in the ICW or ocean I could see going stainless.

                      waiting to see what my friend comes up with from his stash.

                      Comment


                      • #12
                        hey Ken, we`ve been running in the new repower a bit more. last week held the throttle open until about 4200 for about 15 seconds and backed down to our normal varying rpms between 2500 - 3500. @ 4200 we saw 46.9 on the garmin gps,.smooth waters, calm wind. this week during our run of varying speeds we pushed her a little harder, and 4300 trimmed good brought 50.6 mph in the light chop. But she gave me a bit of feedback that I`m fuel starved, she didn`t stall or bog down, just a slight loss in power and after 20-25 seconds of WOT I got out of it until I can diagnose whats up.
                        30 gallons, 2 adults, gear, 14x19 4 blade.
                        at this point the rebuild has some goodies in her, weiand intake, holley 650 spread bore, better flowing exhaust manifold with thru hulls only, to much water thru the pipes could be it as well. I`m going to check a few things before I run her at WOT again. ie: fuel pressure. she is thirsty girl... could be the vacuum secondaries on the carb to,,,

                        planning off is very good, midrange punch is great, the boat pulls hard and is faster than I thought. I think there is more in her...

                        Comment


                        • #13
                          Sounds good so far, curious if you find your fuel restriction if things get any better or not.
                          tank vented properly?

                          Ken Reeves
                          [email protected]
                          941-735-5808

                          Comment


                          • #14
                            Originally posted by ken2 View Post
                            Sounds good so far, curious if you find your fuel restriction if things get any better or not.
                            tank vented properly?
                            tank is standard venting from the manufacturer, but that`s not saying that bugs didn`t get inside the hose. I do not see the plastic tank collapsing, and geez Im not looking forward to removing the pick up tube if I need to, they never reseal properly. under normal loads up to that point of 4300rpms, you wouldnt know anything was amiss. if you never broke that threshold ya`d never know...
                            So This Holley is a universal calibration, I`ll also be looking into that... Thanks Ken!

                            Comment


                            • #15
                              ok, vent ok, tank fill ok, found the water separator was full and a bit of water made its way to the Holley carb. But I`m pretty sure the issue was the prop size. we did some back to basic/stock work to get a baseline by removing the new Holley 650 spreadbore and installing the Rochester Carb, the metal fuel line restored, and new fuel filters. Another prop to try was the 14 1/2 x 17 four blade. Water test was today as the season is ending and I wanted to see the results before she took a nap. Now we can achieve 4800 rpms, @ 50-51mph, I`m sure there is a tick more with better water and trim, and less weight. We had 30 gallons, 2 adults and gear on board... not to shabby... and we are still running in the new engine...

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