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    questions about 5.7 vortec engine, full installation, or heads only?...

    with the extra bit of horsepower and fuel economy from the vortec engine with its throttle body injection and roller cam, I am thinking of replacing my current 5.7sbc with a 5.7vortec motor... BUT...

    is there a difference between the early vortec engines and the later ones?.... i have heard the early ones didnt use an ecm.... where these roller cam motors?

    the vortec engine seems to be a bit taller, is it?.... will it fit under the hatch of a 2556?

    how much of a nightmare is the wiring harness and ECM installation?..

    does it have to be a special programmed ECM for a marine engine?

    I assume because the vortec is a sbc motor, the motor mounts are the same, but are there any other problems I may encounter that is out of the norm?


    or, from those that have done the full engine installation, would it be recommended to just install a set of vortec heads on my current perfectly running engine?...


    NU LIBERTE'
    Salem, OR

    1989 Bayliner 2556 Convertible
    5.7 OMC Cobra - 15.5x11 prop
    N2K equipped throughout..
    2014 Ram 3500 crew cab, 6.7 Cummins
    2007 M-3705 SLC weekend warrior, 5th wheel
    '04 Polaris Sportsman 700 -- '05 Polaris Sportsman 500 HO
    Heavy Equipment Repair and Specialty Welding

    #2
    How many hours on your motor and what is the horsepower?
    On my 2252 I swapped in a 330hp Michigan motorz vortec with edelbrock carb. Hardest part was adding electric circuit for fuel pump. It was easy!
    i gained over 10mph and went from 1mpg to 2 mpg.
    But, the prior motor was probably a truck motor that someone swapped in. It was 2 barrel, and wrong power band.
    What im saying is I went from a crappy engine to a real good one and had real good results.
    I don't think you'll have such good results as your engine sounds decent. I don't think just swapping heads will be that noticeable.
    Esteban
    B-ham!
    Former Bayliners 3218, 2859, 2252, 1952

    Comment


      #3
      Try thinking of it on a return on investment basis. If your plan is to keep the boat for a long time, you feel it’s a bit underpowered and you use the heck out of it, then it can make sense to do a total package. I repowered our 1980 2950 Encounter Sunbridge in 2001 after one of the original 470’s cracked a block with new 205hp 4.3’s and counter rotating Alphas. It completely changed the boat. My cruise speed increased and fuel burn decreased. We sold the boat in 2017 after putting 1000 hours on them. I did the installation myself and even though I was converting from a four cylinder to a v6, it wasn’t difficult. It wasn’t plug and play, we built a new harness going from the pigtail to the dash, it was a matter of finding the right color, gauge wire and connectors. Use tinned wire and marine shrink/glue connectors. Btw, the new ABYC standard for negative wire is yellow.
      I’m not familiar with the newer versions, but the 01’s were roller cam and the only fuel injection then was throttle body injection so I considered it a why bother. Now, with the true fi, it would be my preferred configuration. I’m sure the cam has changed and everything would be marine specific because of the way the engine operates, constantly under load not having any “downhill” time.
      P/C Pete
      Edmonds Yacht Club (Commodore 1993)
      1988 3818 "GLAUBEN”
      Hino EH700 175 Onan MDKD Genset
      1980 Encounter Sunbridge "Misty Blue" (Sold)
      MMSI 367770440
      1972 Chevrolet Nova Frame off Resto-mod in the garage
      Boating on the Salish Sea since 1948

      Comment


        #4
        I think you might get more bang for the buck with a carbed 383.
        Esteban
        B-ham!
        Former Bayliners 3218, 2859, 2252, 1952

        Comment


          #5
          Im not sure of the hours on my current motor, but due to a glitch of my own doing, i had to replace one piston, and while i had it apart I replaced the rings on all pistons.. the engine is a custom rebuild, installed in 2011, but it does NOT have the preferred pistons in it...... and I do plan on having the boat for a long time...

          so with it not having the correct pistons, and because I have the skills and the time ,i wanted to buy an engine and do the rebuild in shop at my leisurely pace, as my current engine runs fine so there is no hurry

          I have all the skills and tools necessary, but I have had no experience with the vortec engine, so its information of the engine itself that I need......

          IF I were to install vortec heads on my current engine, do i need a different intake manifold, or is it better to get different style of heads for this engine and use my current intake manifold.....

          And I fully take into consideration the advice that this endeavor could be a waste of time and money, but without more knowledge about the conversion process, I wont know if I feel its its a waste of MY time and MY money....


          NU LIBERTE'
          Salem, OR

          1989 Bayliner 2556 Convertible
          5.7 OMC Cobra - 15.5x11 prop
          N2K equipped throughout..
          2014 Ram 3500 crew cab, 6.7 Cummins
          2007 M-3705 SLC weekend warrior, 5th wheel
          '04 Polaris Sportsman 700 -- '05 Polaris Sportsman 500 HO
          Heavy Equipment Repair and Specialty Welding

          Comment


            #6
            if you end up installing Vortec heads on your current engine you’ll also need a Vortec intake manifold as the bolt pattern is different. I did this to mine, Summit has a good price on those Vortec heads. And if you put the proper quench style piston in you’ll actually gain the advantages the Vortec combustion chamber offers.
            Dave
            Edmonds, WA
            "THE FIX"
            '93 2556 5.7 Bravo II 2.0:1 18 1/4x19 P
            (.030 over-Vortec top end-part closed cooled)
            The rebuild of my 2556 https://www.baylinerownersclub.org/f...76?view=thread
            Misc. projects thread
            https://www.baylinerownersclub.org/f...56-gctid789773

            Comment


              #7
              I believe the carbed 5.7 vortecs in my 2000 3055 have roller cams. I've heard the heads are worth about 30hp.
              Sea Venture
              2000 3055, 5.7/B2, 18x23" props
              Cruising the PNW and beyond.
              DIYC, Riverhouse Marina
              MMSI 316029971

              Kirk
              Drinks well with others.

              Comment


                #8
                You will need a Vortec intake manifold, and if you have a 4bbl Quadrajet, you will need to convert it to an electric choke because the Vortec style manifold does not use an exhaust crossover that was used to heat the thermostatic spring for the choke to open it as the engine warms up. There are electric conversions for the Q-Jet carb but you can also upgrade to the Edelbrock (if it will clear the Cobra shift linkage on the starboard side, I know it does not on the V6 models) or a Holley 4bbl, both come with electric chokes.

                While Throttle body injection will start easier than a carb engine and run smoother cold, it will not necessarily produce more power than a well set up carb. The wiring is more complex and you need to use an ECM and the needed sensors. This I think will exceed the cost of a brand new 4bbl carb which will work great on that engine. The Edelbrock is a well known and reasonably priced way to go, the Holley is a bit more expensive, but you can buy them already calibrated for different engine sizes, thereby eliminating some guess work.

                If the engine you have now has good compression, does not burn oil and is not making concerning noises, I'd probably run it until you need to replace it in which case I'd go with a long block Vortec replacement. While the Vortec heads do add power, its a lot to pay for maybe 20-30 hp. I'd keep the carb vs MPI. I think the carb is far simpler in terms of installation. Also keep in mind that if you change the original points distributor, the ESA that lowers the idle speed for shifting to neutral will not work, you will need to buy a new ESA that works with electronic ignition or wire it like a Merc. If the points distributor is in good shape I'd just keep using it. Points are simple, and do not have any electronic mystery boxes that can be hard to find if they fail on a 30 year old boat. You may already have a roller cam, my '88 non-Vortec 4.3 for sure has one. I have read that they converted over in the '87-88 time frame but this could vary depending on the stock of engines on hand.
                88 Four Winns 200 Horizon 4.3 OMC
                98 Jeep Grand Cherokee 4.0/Selectrac
                07 Jeep Grand Cherokee 5.7 Hemi/Quadradrive II

                Long Island Sound Region

                Comment


                  #9
                  Regarding the intake manifold preVortec were 12 bolt and the Vortec is 8 bolt. I believe the angle between the intake and heads is different.
                  1997 Maxum 2400 SCR 5.7LX Bravo II

                  Mike

                  Comment


                    #10
                    The angle of the bolts is what's different, the non-vortec bolts go in at an angle to the intake but square to the head surface, whereas on the vortec, the bolts go in square to the intake but at an angle to the heads.
                    88 Four Winns 200 Horizon 4.3 OMC
                    98 Jeep Grand Cherokee 4.0/Selectrac
                    07 Jeep Grand Cherokee 5.7 Hemi/Quadradrive II

                    Long Island Sound Region

                    Comment


                      #11
                      I replaced my non-vortec head with vortecs and it worked out great. As they said above, you'll need a new intake... but any SBC, regardless of year, that uses Vortec heads, will require an external coolant bypass linefrom the intake manifold to the 5/8" hose nipple on the water pump (passenger’s side). Suggested routing is from the 3/8 NPSF boss on intake manifold to the water pump. The Vortec does not have that hole/passageway so the external bypass is required. I neglected to do this and the engine would overheat as the coolant wasn't circulating properly. Once I added the bypass it worked like a charm!
                      1995 Bayliner 2452 Mercruiser 5.7L Alpha 1 Gen 2

                      Comment


                        #12
                        From 96 & up starting with Mercruiser tbi engines, by production year 98 almost all are Vortec.
                        Joon, Kathy, Jaden & Tristan
                        Uniflite 42 AC, DD 671N
                        93 3058 sold
                        92 2855 (day boat)
                        91 Fourwinns 205 (lake boat)
                        Longbranch WA
                        Life is Good

                        Comment


                          #13
                          Originally posted by Fishtank View Post
                          I replaced my non-vortec head with vortecs and it worked out great. As they said above, you'll need a new intake... but any SBC, regardless of year, that uses Vortec heads, will require an external coolant bypass linefrom the intake manifold to the 5/8" hose nipple on the water pump (passenger’s side). Suggested routing is from the 3/8 NPSF boss on intake manifold to the water pump. The Vortec does not have that hole/passageway so the external bypass is required. I neglected to do this and the engine would overheat as the coolant wasn't circulating properly. Once I added the bypass it worked like a charm!
                          Im confused by this. What hole/passageway are you referring to? The cooling jacket in a Vortec head is the same as the cooling jacket in the non Vortec head, same with the intake manifolds. The only real difference that I'm aware of between the two is in the improved combustion chamber design, intake runner design and the lack of the exhaust crossover on the Vortec head.
                          Dave
                          Edmonds, WA
                          "THE FIX"
                          '93 2556 5.7 Bravo II 2.0:1 18 1/4x19 P
                          (.030 over-Vortec top end-part closed cooled)
                          The rebuild of my 2556 https://www.baylinerownersclub.org/f...76?view=thread
                          Misc. projects thread
                          https://www.baylinerownersclub.org/f...56-gctid789773

                          Comment


                            #14
                            I finally got in touch with a performance boat builder that has done many vortec conversions.... both the early TBI vortecs and the later EFI models.... I learned a lot talking to him.

                            his recommendations are nearly parallel to what I have received here so far, but I know they are only opinions....

                            his input and recommendations about the vortec engine are as follows...

                            stay away from the TBI set up and get a carb style manifold, as a good carb tuned properly will give better performance AND better fuel economy in a boat.

                            the vortec EFI is more fuel efficient than the carb, but the carb will still noticeably out-perform it.

                            vortec heads on a regular block adds about 20-30hp, and the proper pistons can give another 12-15hp when used with vortec heads... the roller cam block can add another 30% gain over just heads and pistons...

                            a vortec block (roller cam), running a carb will deliver 60-80hp over the regular un-modified 5.7

                            the installation of the carbed engine is quicker and a lot easier.

                            the early vortec blocks are preferred, as they have a hole (capped) for a mechanical fuel pump... the later blocks did not have the option/hole for a mechanical pump, so an electric pump is necessary.

                            its an easy conversion/swap for someone who knows how to remove and replace an engine.....


                            I can buy a running vortec "core" engine for anywhere from $250 to $500, I can take my pick of several, TBI or EFI.... so depending on the internal condition of the engine I choose, i will at the very least have a set of heads, (need to buy a carb style intake) and if the rest of the core is in reasonable condition, I will have something I can build on without a need to hurry, and still not miss any of the season while running my current engine....

                            My current engine is the 260hp version, and already has an electronic ignition distributor, so I can use it in the vortec block..

                            with this information, I plan to move forward with my "project".....






                            NU LIBERTE'
                            Salem, OR

                            1989 Bayliner 2556 Convertible
                            5.7 OMC Cobra - 15.5x11 prop
                            N2K equipped throughout..
                            2014 Ram 3500 crew cab, 6.7 Cummins
                            2007 M-3705 SLC weekend warrior, 5th wheel
                            '04 Polaris Sportsman 700 -- '05 Polaris Sportsman 500 HO
                            Heavy Equipment Repair and Specialty Welding

                            Comment


                              #15
                              Originally posted by 88fourwinns View Post
                              The angle of the bolts is what's different, the non-vortec bolts go in at an angle to the intake but square to the head surface, whereas on the vortec, the bolts go in square to the intake but at an angle to the heads.
                              There is an in between type early Vortec head "swirl port head". All 12 bolt holes at the intake manifold interface are present but the center four bolts thread in at a different angle than the rest. Later to current style Vortec head uses only eight bolts at the intake manifold interface (no center bolts), and as you say they thread in vertically instead of square to the head.
                              Dave
                              Edmonds, WA
                              "THE FIX"
                              '93 2556 5.7 Bravo II 2.0:1 18 1/4x19 P
                              (.030 over-Vortec top end-part closed cooled)
                              The rebuild of my 2556 https://www.baylinerownersclub.org/f...76?view=thread
                              Misc. projects thread
                              https://www.baylinerownersclub.org/f...56-gctid789773

                              Comment


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