User Tag List

Page 2 of 2 FirstFirst 1 2
Results 16 to 21 of 21
  1. #16
    Join Date
    Aug 2001
    Location
    St. Cloud, FL
    Posts
    4,108
    Mentioned
    0 Post(s)
    Tagged
    1 Thread(s)
    Quote Originally Posted by FUJIMO View Post
    ...proper tie bar adjustment. toe in or toe out, is critical, depending on which direction your turning the props. one tie bar adjustment does not work for both rotations. on a twin install that is surfacing, be they inboard or outboard, it has always been common belief by even the best performance(and non performance) riggers out there, that the leading edge of the gearcases be adjusted pigeon-toed when the propellers are rotating outboard. I believe it to be, in fact, the exact opposite, and have proven this to the likes of bobby moore, don schwebs, bob latham, and others... drive alignment at speed affects water pressure, prop performance, handling, lift, and on & on... its important.
    I would agree with you. I would think ideally, you want the cases to be perfectly straight at speed, so you toe in or out to compensate for any "intolerance" or play in the rigging. Turning props out wants to push the rear of the cases apart, whereas tuning in wants to suck them together.
    2006 Spectre 24' SCS
    2020 Mercury 300 ProXS

    2001 Allison XB2003
    2006 Mercury 250XS

    1988 22' Velocity (sold)

    1995 Allison Grand Sport (sold)
    1998 Mercury Stock 2.5-260 SS

    1990 Velocity 30' - 502's (sold)

    Go Daddy Go! Racing

  2. #17
    Join Date
    Aug 2006
    Location
    virginia
    Posts
    662
    Thanks (Given)
    39
    Thanks (Received)
    63
    Likes (Given)
    277
    Likes (Received)
    725
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by FUJIMO View Post
    ...proper tie bar adjustment. toe in or toe out, is critical, depending on which direction your turning the props. one tie bar adjustment does not work for both rotations. on a twin install that is surfacing, be they inboard or outboard, it has always been common belief by even the best performance(and non performance) riggers out there, that the leading edge of the gearcases be adjusted pigeon-toed when the propellers are rotating outboard. I believe it to be, in fact, the exact opposite, and have proven this to the likes of bobby moore, don schwebs, bob latham, and others... drive alignment at speed affects water pressure, prop performance, handling, lift, and on & on... its important.

    EXELLENT POST...

    please elaborate on this since there is a lot is a lot of ideas from everyone under the sun. one would assume measuring the centerline of the engines first...then measuring the centerlines of the bullet and then the prop shafts all to be the same. i..then would assume you would get the least amount of drag in a neutral position... not toed in or out creating less drag on the gearcases. in this application what is the perferred position for maximum speed. 1:62 sport master, 15 x 32 merc labbed cleavers turning out, 26 american offshore 18 inches of setback. its a bit slow at 98 mph light load.

    Click image for larger version. 

Name:	20170918_081948.jpg 
Views:	14 
Size:	136.9 KB 
ID:	471114
    Last edited by SUNKIST; 08-06-2020 at 12:13 PM.

  3. #18
    Join Date
    Jan 2004
    Location
    Florida
    Posts
    37,827
    Thanks (Given)
    64
    Thanks (Received)
    1667
    Likes (Given)
    337
    Likes (Received)
    19201
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by SUNKIST View Post

    EXELLENT POST...

    please elaborate on this since there is a lot is a lot of ideas from everyone under the sun. one would assume measuring the centerline of the engines first...then measuring the centerlines of the bullet and then the prop shafts all to be the same. i..then would assume you would get the least amount of drag in a neutral position... not toed in or out creating less drag on the gearcases. in this application what is the perferred position for maximum speed. 1:62 sport master, 15 x 32 merc labbed cleavers turning out, 26 american offshore 18 inches of setback. its a bit slow at 98 mph light load.

    Click image for larger version. 

Name:	20170918_081948.jpg 
Views:	14 
Size:	136.9 KB 
ID:	471114
    ...honestly, "there being a lot of ideas from everyone under the sun", are not "proven" ideas. my career proved what i learned, to actually work, through untold years of testing. most all of it hi-performance. without seeing & touching your boat in person, there is so much more to know & learn about your particular boat, i would just be generalizing, as every boat is different. even boats that came out of the same mold sequentially. hard to believe. for example, not even knowing what horsepower your engines are, and having absolutely no idea what your boat weighs(important), i would wildly guess that if your capable of turning those 15 x 32 what ever they are props, at the engines rated WOT rpm(could be more, could be less...)...that your cruis'n along pretty good the way you are. But, there are so many variables that come into play, that again, it would be simply generalizing.

  4. Likes tunnelfun liked this post
  5. #19
    Join Date
    Jan 2004
    Location
    Florida
    Posts
    37,827
    Thanks (Given)
    64
    Thanks (Received)
    1667
    Likes (Given)
    337
    Likes (Received)
    19201
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    ...measure at the leading edge of both gearcases. measure centerline at back end of propshaft, to centerline at back end of propshaft. this tells you where you currently stand. i prefer to do this when both props are off, to be the most accurate. thats just me. on the trailer, level parking area, motors/drives trimmed straight up & down, pointing straight ahead. any play in the steering due to air, or loose or sloppy hydraulic cylinder(s) ends or hardware, tiebar ends worn/loose, engine motor mounts worn/loose, etc? these & more come into play for an accurate alignment measurement while static, and while under a load.
    Last edited by FUJIMO; 08-06-2020 at 01:20 PM.

  6. #20
    Join Date
    Apr 2003
    Location
    New Smyrna Beach, FL./LOTO
    Posts
    6,606
    Thanks (Given)
    600
    Thanks (Received)
    901
    Likes (Given)
    1679
    Likes (Received)
    7085
    Mentioned
    3 Post(s)
    Tagged
    1 Thread(s)
    The issues that you are dealing with is precisely why having a GOOD pair of hydraulic brackets is vital to everything. Very seldom will you NOT see: 1. motors are at different heights to match water pressure side to side (a balance tube connecting the motors helps). 2. Propellers change water pressure 3. Trim indicators be accurate. (one motor being trimmed just slightly more then the other is causing the boat to want to "twist" which leads to all other issues). 4. Motors misaligned. Its hard to get the motors aligned perfect with out laser guidance (I have thought mine were perfect, put a set of lasers from STR on the shafts and surprise "I was way off") --As mentioned above this affects propeller efficiency, case lift, handling, water pressure, and overall drag.

    Engine height and trim is "the key to the city" with a cat (especially when you want to run on the edge with a big surfacing case like we are now). You will be amazed at what your boat will do in the rough water with the motors dropped two inches from kill compared to someone that has theirs on the edge and in a fixed position.

    Jack Plates: I personally like the Porta Brackets or Stainless Marine Gorilla plates only but I am sure that there are other solid ones out there that I am not aware of. Adjustability and accurate monitoring makes solving these problems a piece of cake as long as you have it hooked to a smart craft display for monitoring trim, pressure, rpm, speed, and (height -to use as a future baseline). Trim indicators: (digital or Stainless marine are my go to choice only).

    Its all in the final details to make something go from good to great.

    Hope this helps,

    Joe

  7. Likes FUJIMO, Beak Boater, HydroSkreamin liked this post
  8. #21
    Join Date
    Feb 2004
    Location
    Palm City Fla
    Posts
    7,197
    Thanks (Given)
    0
    Thanks (Received)
    831
    Likes (Given)
    0
    Likes (Received)
    6491
    Mentioned
    13 Post(s)
    Tagged
    1 Thread(s)
    Quote Originally Posted by Davidlake View Post
    Water Ramps like this?? Sure do!

    Ohh sure , now I got "ramp envy" ….

    They do look like that though .. only smaller ..

    Zero to three eights deep over an eight inch span . Why are they two and a quarter inch's wide … ? Cuz that's how wide my air file is …
    Un~common sense says that they should be maybe a quarter inch deep on the outside and a little more than a half inch deep on the inside to negate the seventeen degree dead rise of the sponson .. or maybe I should lean the motors in at the top to match the notch's …
    Putting trust in the people who made the boat is nice . Same for the people who rigged it . Truth is , none of them are perfect . The best you can do is find some level ground , level the transom (use the trailer tires air pressure in you have to. Measure from the ground to the keels , strakes , engine mount holes , any place you can use as a reference . Told ya they aren't perfect .. It's not that big of a deal , if the bottoms are flat when the transom is three tenths of a degree to one side. That's your base that you can return to any time.
    When I bought my cat , the jackplates were crooked and a quarter inch different from side to side. I reused the four half inch bolts on each engine and when I came back and looked they were both leaning .. noticeably .
    I built my own plates , mounted them correctly with six bolts to the boat and eight bolts from the motor to the plates.
    BTW .. when they moved , it threw the "toe" off by a quarter of an inch . It didn't change , speed , RPM , or water pressure . It did handle as bad as Bubba Wallace drives . If entry angle changed water pressure , no one would ever be able to make slight adjustment to the wheel at speed , let alone make a full ……. turn
    Propshaft height , with the keel level and the propshafts level . ( I check across the flywheels when I'm alone ) I have a four foot long straight edge with a "flag' that's I scribed a line on every eighth of an inch . Clunk ,against the bottom , slide back till it touch's the gear case .. Quick , simple , accurate .. and about $6 worth of aluminum .
    Tow in / out , Lets say the props are spinning "out" . They are on top of the water , well half of it . So the blade goes in the water on the outboard side of the shaft , scoops down , inward and up .. seems "out" is slang , compared to direction of work.
    Tow .. how you see fit ..
    Me , I remember .. no , that's not true. I had to take the props off and look at my notes... Then it took someone else on the other side . No don't use the little bent up clip on the end . Hold it where the one inch line is against the little dot on the front of the case .. No , the other one inch , yes the longest line beside the number one .. &&*%%^**( @%^*( #&^*(#$ .. yes your fired , you cant ever read a *&^%^*** tape measure ..
    So I have a bar of aluminum with a hole at one end that slips over the nose of the sporty … and yes the other side has scribe marks . I already know my number , so no I don't waste time removing prop's , finding level ground , plumb bobs etc. . I did that once already … doing it over and over again only proves I wasn't paying attention the first time ..
    I tried remote pick-up's , erratic pressure readings at best. A fellow G.O.B.I.T. graduate said, Waelp Charlie , with yur boat a bouncin up an down in the ocean , seems to me that the bottom of the boat aint a always touchin the water . But I'll betcha you don't jump it hi enough to have that lower unit sukkin air .
    I ditched the remote *^&$%&^*(*( *(^%^ and worked the water inlets to
    "The Witch's Nose" standards .. and went from 9 -10 lbs to 22 pounds @ the same height .. but that's not for a motor that Mercury is responsible for , but then neither would be drillin and tappin holes fer crossover lines , remote pick-ups .. five gallon buckets with a hand pump etc .. Looks like the best ya can do is take the time to learn what ya got ( or more important listen to it tell you what "IT" wants) .. or waller out the holes on the left side , drop that behemoth an eighth inch an send it ..

Page 2 of 2 FirstFirst 1 2

Similar Threads

  1. 25 daytona twin 300r
    By city in forum General Boating Discussion
    Replies: 5
    Last Post: 03-31-2020, 05:47 PM
  2. 25 daytona twin 300r
    By city in forum General Boating Discussion
    Replies: 14
    Last Post: 03-23-2020, 04:09 PM
  3. 1994 21' Eliminator Daytona Twin 260's
    By AH22 in forum Hulls larger than 20'
    Replies: 8
    Last Post: 11-18-2019, 07:34 PM
  4. Eliminator Daytona twin 2.5 260’s
    By 91daytona in forum Hulls larger than 20'
    Replies: 7
    Last Post: 03-11-2019, 10:51 PM
  5. 25 daytona repower from twin yamaha 300hpdi to mercury 300r
    By city in forum General Boating Discussion
    Replies: 1
    Last Post: 01-04-2019, 01:05 PM

Posting Permissions

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