Page 2 of 9 FirstFirst 1 2 3 4 ... LastLast
Results 21 to 40 of 164
Like Tree127Likes

Thread: 40 OL - Mild Upgrade

  1. #21
    PBN User kidturbo's Avatar
    Join Date
    Jun 2013
    Location
    Somewhere on the Ohio
    Posts
    561
    WWW.MARINEMODS.US


    Ignore User
    Quote Originally Posted by BajaDan View Post
    And just to be clear, you are saying the transom angle is 15 degrees (measured in relation to the running surface or the pad on centerline?) and the extension box is designed for a transom angle of 12 degrees resulting in an extension box angle of 3 degrees down.
    Yeah, we only used a straight edge and speed square to check both, and that's what we came up with. However looking at at a SSM V mounting drawing, it shows 12 deg being the normal transom angle. On this VI drawing below it doesn't state the exact angle, but does give some other useful dimensions. Will check all these measurements again today and post up here.

    For driveline locations, I know it's 36" exactly between the crankshafts. We measured that when the gas engines were still installed. So 18" centerline... Problem is input shaft height has now changed. The X-dimension is either 3.6" lower, or about 4" higher with the Weismann setup. Without the gear boxes installed, the Weismann shafts are only 15" apart vs 18.63" on a #6. But with the gear box installed, that figure jumps to like 21" or so. See flange location in pics above..

    If I removed the gearcase setup from inside the drive housing, flip it over and mount to back of the trans, then I can lower the engines 4" from previous setup. If not, I would need to raise them up 4" now to achieve a straight driveline layout. Also see in pic above how the flange sets about 3" off center on one drive due to that three gear arrangement. Kinda why I need to know exactly where to mount up the drive boxes before moving on to building engine mounts.

    Name:  VI-Dem.jpg
Views: 59
Size:  81.5 KB

  2. #22
    PBN User BajaDan's Avatar
    Join Date
    Feb 2013
    Location
    Alabama
    Posts
    5,354
    "Tinker Toy" - Baja 252 Islander


    Ignore User
    Good information here. Now if they only showed us where the vertical trim pivot is, we would be in business.

    I don't think there is a "standard" transom angle, at least not that I can find from Merc. Most seem to be around 12 degrees but 15 would not be bad. As a matter of fact, it may help since it may help tuck the drives more and make it easier to get on plane.

    Height is an issue though.

    It is interesting that they show X as measured parallel to the transom and not vertical (perpendicular to the running surface). Some small error based on transom angle is introduced there.

    These SSM's are monsters. Are they dry sump?

    Can you post or shoot me the SSM mounting diagram? dcopeland@mcwaneglobal.com

  3. #23
    PBN User kidturbo's Avatar
    Join Date
    Jun 2013
    Location
    Somewhere on the Ohio
    Posts
    561
    WWW.MARINEMODS.US


    Ignore User
    A side by side comparison of shaft heights as viewed from inside the transom.


    Name:  20160609_183739.jpg
Views: 62
Size:  109.9 KBName:  20160717_180136.jpg
Views: 61
Size:  111.8 KB

  4. #24
    PBN User Jwiniger83's Avatar
    Join Date
    Feb 2013
    Location
    Mount Vernon, IN
    Posts
    559
    2009 Baja 277 Islander


    Ignore User
    Are you going to have clearance for all of the plumbing associated with those big turbo diesels? I assume you are running multiple turbochargers.

  5. #25
    PBN User kidturbo's Avatar
    Join Date
    Jun 2013
    Location
    Somewhere on the Ohio
    Posts
    561
    WWW.MARINEMODS.US


    Ignore User
    Stumbled onto this page with about all the technical drawings Merc ever made

    http://download.brunswick-marine.com...egories=&mod=7

    Also here is a nice write up explaining surface piercing drive configurations and considerations. Basically says waterline should run through the hub at speed. IF I run them full surfacing as Weismann designed.

    SURFACE-PIERCING PROPELLERS

  6. #26
    PBN User kidturbo's Avatar
    Join Date
    Jun 2013
    Location
    Somewhere on the Ohio
    Posts
    561
    WWW.MARINEMODS.US


    Ignore User
    Quote Originally Posted by Jwiniger83 View Post
    Are you going to have clearance for all of the plumbing associated with those big turbo diesels? I assume you are running multiple turbochargers.
    Yeah it's actually a more compact setup with the twin turbos than the Blown BBC's and full length headers. Here is about what it will look like, but with turbos facing fwd like a QC4v setup.

    Name:  DuramaxMarineV8_1gb_opt.jpg
Views: 65
Size:  152.9 KB

    This boat has a custom hatch cover that could be replaced with a nice flat sun pad, if you guys know of any 40 OL's owners who would like to trade....

    Name:  rearcover.jpg
Views: 63
Size:  134.7 KB
    Last edited by kidturbo; 07-20-2016 at 09:32 AM.
    92nsx likes this.

  7. #27
    PBN User BajaDan's Avatar
    Join Date
    Feb 2013
    Location
    Alabama
    Posts
    5,354
    "Tinker Toy" - Baja 252 Islander


    Ignore User
    Quote Originally Posted by kidturbo View Post
    Stumbled onto this page with about all the technical drawings Merc ever made

    http://download.brunswick-marine.com...egories=&mod=7

    Also here is a nice write up explaining surface piercing drive configurations and considerations. Basically says waterline should run through the hub at speed. IF I run them full surfacing as Weismann designed.

    SURFACE-PIERCING PROPELLERS
    Great info! Unfortunately it still does not give the pivot location which we need. A simple measurement though.

  8. #28
    PBN User BajaDan's Avatar
    Join Date
    Feb 2013
    Location
    Alabama
    Posts
    5,354
    "Tinker Toy" - Baja 252 Islander


    Ignore User
    I have read Kamen before. It is a great explanation, particularly the part about suppressing cavitation. Good find.

  9. #29
    PBN User BajaDan's Avatar
    Join Date
    Feb 2013
    Location
    Alabama
    Posts
    5,354
    "Tinker Toy" - Baja 252 Islander


    Ignore User
    Here is a geometrical analysis I did for a hypothetical 25 foot Bravo 1 boat. We need to do the same with yours. Boat trim is assumed at 4 degrees, engine trim is shown at 2, 4 and 6 degrees. Prop depth is shown as the dimension to the lower right. Notice the huge variation in depth at relatively these small trim adjustments.

    Name:  Prop Depth 2deg.jpg
Views: 58
Size:  55.2 KB

    Name:  Prop Depth 4deg.jpg
Views: 59
Size:  53.7 KB

    Name:  Prop Depth 6deg.jpg
Views: 63
Size:  54.7 KB
    Last edited by BajaDan; 07-20-2016 at 10:58 AM.
    hook'em likes this.

  10. #30
    PBN User kidturbo's Avatar
    Join Date
    Jun 2013
    Location
    Somewhere on the Ohio
    Posts
    561
    WWW.MARINEMODS.US


    Ignore User
    Roughly 32" off the transom is the pivot point. 15" below that pin is our prop shaft, with 30" beyond that line to our leading edge of the prop. The boxes have room to move holes UP 2.5" if need be.

    Also checked the transom angles again. The stand off box is defiantly 12deg, and after checking the transom in 3 places, I think it's closer to 12deg. She has a bit of a bow where transom meets the bottom that was throwing off my straight edge and speed square technique... Not a hook in bottom as you would expect, but a bow from big HP pushing the transom fwd for years.

    Either way, I seriously gotta find my driveline angle tool cause the straight edge way SUCKS!!

    Name:  20160720_210105.jpg
Views: 50
Size:  111.6 KB
    Last edited by kidturbo; 07-21-2016 at 12:52 AM.

  11. #31
    PBN User BajaDan's Avatar
    Join Date
    Feb 2013
    Location
    Alabama
    Posts
    5,354
    "Tinker Toy" - Baja 252 Islander


    Ignore User
    Probably good enough for our purposes.

  12. #32
    PBN User BajaDan's Avatar
    Join Date
    Feb 2013
    Location
    Alabama
    Posts
    5,354
    "Tinker Toy" - Baja 252 Islander


    Ignore User
    Ok. Here is the basic data with a couple of assumptions on my part.

    Name:  IMG_5945.jpg
Views: 55
Size:  92.9 KB

    The X dimension is calculated based on your observations that the prop shaft is even with the bottom of the transom. If possible you can verify this dimension.
    The prop center is 70.88 inches (calculated) back from the bottom of the transom.
    Crankshaft is offset 18 inches from the boat centerline.
    The boat trim is assumed to be 4 degrees and the drive is trimmed to match.
    What diameter prop are you planning on running? Not that it really matters as we are basing all calculations off the centerline of the prop shaft.

    If you think this is what you've got now, then we can start playing with the variables.
    hook'em likes this.

  13. #33
    PBN User BajaDan's Avatar
    Join Date
    Feb 2013
    Location
    Alabama
    Posts
    5,354
    "Tinker Toy" - Baja 252 Islander


    Ignore User
    Playing with the model as it is, you change prop height about 1.25 inches for every 2 degrees of trim change, at least for values around the neutral position. If the boat trim goes to 6 degrees (a 2 degree change) and you compensate the drive trim to suit, the prop ends up getting buried an additional 1.3 inches.

    What all this means is that the variation in boat trim is not nearly as significant as we first thought. The larger the prop you swing, the less that 1.3 inch variation makes a difference.

    Right now it is looking like you need to raise the drive about 1.5 inches depending on boat trim. That 1.5 inches would be close enough to compensate by trim. Or leave it where it is a be slightly deep.

  14. #34
    PBN User kidturbo's Avatar
    Join Date
    Jun 2013
    Location
    Somewhere on the Ohio
    Posts
    561
    WWW.MARINEMODS.US


    Ignore User
    Ok I see what your doing now.

    The actual X would be 15" on this drive, if the prop shat is at centerline to bottom. A #6 has 18.6" centerline, but Weismann is only 15". Also I think your gimbel pin point would need be on that 15" line too? Look at pics above.

    For props, it will likely be running a 17-18 dia.

  15. #35
    PBN User kidturbo's Avatar
    Join Date
    Jun 2013
    Location
    Somewhere on the Ohio
    Posts
    561
    WWW.MARINEMODS.US


    Ignore User
    Also in my previous statement I said move holes up. I meant room to move box up 2"..

    I took time yesterday to measure those gear boxes. They are 6" centerline input to output, or drop. Currently that unit is mounted in the drive box, directly to the drive input shaft. Which makes the true driveline height 21" above prop shaft. HOWERVER, I am going to attempt to move those from there to transmission, which means setting engines 6" lower and our drieline center goes back down to 15" as I listed.
    BajaDan likes this.

  16. #36
    PBN User BajaDan's Avatar
    Join Date
    Feb 2013
    Location
    Alabama
    Posts
    5,354
    "Tinker Toy" - Baja 252 Islander


    Ignore User
    I will make the change to an X of 15 but if you are running a jackshaft it won't make any difference as crank centerline does not have to be lined up with the pivot like a plug in would be. What I really need is a pivot height above the transom bottom measuring any way you like to get there.

  17. #37
    PBN User kidturbo's Avatar
    Join Date
    Jun 2013
    Location
    Somewhere on the Ohio
    Posts
    561
    WWW.MARINEMODS.US


    Ignore User
    Dan, I picked up a couple tools to make this go a little smoother. These self leveling lasers are pretty handy. Leveled the boat up last night and took a couple quick measurements. 15 inches is the bottom mark on the template. I'll mount the drive back up tomorrow and measure it all for real. Tell me what ya need and I'll make it happen.

    Name:  20160721_213159.jpg
Views: 49
Size:  81.9 KB

    Name:  20160721_213407.jpg
Views: 48
Size:  40.7 KB

    Name:  20160721_222035.jpg
Views: 47
Size:  66.9 KB
    Last edited by kidturbo; 07-21-2016 at 09:21 PM.
    hook'em likes this.

  18. #38
    PBN User BajaDan's Avatar
    Join Date
    Feb 2013
    Location
    Alabama
    Posts
    5,354
    "Tinker Toy" - Baja 252 Islander


    Ignore User
    Dang Kid, I was thinking a tape measure would be fine. I like the way you work.

    I was thinking about it last night and we may be there, at least as far as the current setup occurs. We know the prop shaft depth, that is very close (and I am assuming to be exactly) even with the bottom of the hull. This gives us our height since we know the relation between pivot and prop and we get length from you other measurements. We don't really care (well, you do) about the relation between drive and engine so the X dimension, for the purposes of this analysis, is not really a factor.

    What we need to decide on is what to assume for a running angle (between 4 and 6 degrees will be close). I also want to take a look at what advantage or disadvantage the extension box gives you. I will modify the geometry to take that out and run another analysis. I am thinking that box is not your friend in that I suspect that it contributes to prop depth changes with boat trim variations. We are closing in on the number.

    I will try and take a look at this today as I will be leaving the country for a couple of weeks after the weekend and I imagine you don't want to wait for me to get back.

  19. #39
    PBN User BajaDan's Avatar
    Join Date
    Feb 2013
    Location
    Alabama
    Posts
    5,354
    "Tinker Toy" - Baja 252 Islander


    Ignore User
    And I do realize you must run the box. I am just curious.

  20. #40
    PBN User kidturbo's Avatar
    Join Date
    Jun 2013
    Location
    Somewhere on the Ohio
    Posts
    561
    WWW.MARINEMODS.US


    Ignore User
    If I can chase down the UPS truck and get my digital protractor this morning we will have exact figures for everything today. I can set the bottom up at 4deg, and then use the laser level against the prop shaft to project a line onto the Vee along the vertical line above. That should give our difference in height running. Also will get the exact distance of that pin off the transom.

    I was reading several posts about running boxes on similar length boats like Fountains. Reggie said "If the boat ran faster with a box, don't you think I would have put them on from factory??"

    The Weismann case is a larger bolt pattern than the #6 pattern on the stand off box. However it's a one way / one time change that can't be reversed if I take them off and break out a drill....
    Last edited by kidturbo; 07-22-2016 at 07:30 AM.

Page 2 of 9 FirstFirst 1 2 3 4 ... LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •