Automobile Transmission, why not?

Discussion in 'DIY Marinizing' started by Ken Gasch, Oct 5, 2004.

  1. tom kane
    Joined: Nov 2003
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    tom kane Senior Member

    Automobile Transmission,why not?

    I had a look at another local boat yesterday with a Holden 186 motor and hydrodrive auto box,running a hydrodrive unit, that is a propeller pod surface drive.It has been installed many years.Bad luck though,it picked up some large kelp floating,bent shaft and bits.It is almost back to normal now,ready for the new season.It would be interesting to know how many automotive automatic boxes are fitted to boats.
     
  2. blared
    Joined: Aug 2005
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    blared ALFA

    They put car engines on the boats all the time.. Just marinize the engine before u put it in. What they say is that it spends too much gas so most people prefer the diesels. You can even run a drive shaft to the outdrive. For a 17 feet boat, a v6 will be more than enough. You can use the transmission too just install one of those heavy duty tranny coolers. Try to find a small engine.
     
  3. saeble
    Joined: Mar 2005
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    saeble Junior Member

    I think I'm going to try running twin Holden (Chev) V6's in my boat with the standard 4spd auto trans. I expect I will never ever use a couple gears, but at $250 odd dollars US, (cheaper if you buy them with the motor), Im not going to complain. You can avoid the thrust issues if you use some forms of stern drive systems, or build your gland nut/stuffing box with thrust bearing capacity.
     
  4. will go fast
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    will go fast New Member

    Took a Ford 302 out of a truck. . . Rebuilt it, slapped on an Osco Bell Housing, wit a Velvet Drive Clutch..... Rummaged around for Mercruiser Stern Drive exhaust manifolds, Used Rubber hosing for exhaust, had an open circulation system pulling water from the outside, trapping/filter, blow the exhaust out the back end . . End result . .??????? #1 Total cost of around $1400.00 . . Well over 200 H.P. . . . . 1.75:1 gear ratio , 9 pitch left hand wheel, 18" in diameter, cabable of (A) Getting on top, (B) Pushing a barge 120' in lenght of needed, boat could turn on a dime, 24" total draft (wheel and rudder) Advanced fuel efficiency . . No two cycle oil, Took care of the spark problem with additional blowers and fans and efficient deck/intake design . . excellent fuel efficiency, lost the cost of having to use the outboard portion of a stern drive power package . . Dependibility up way way way high . . . I know this is probably years too late being as the origional post was '04 but some of the posts made me laugh me arse off, anyways, right now I am getting ready to hook up some 4 cylinder motors from front wheel drive mini vans onto pontoons for a campboat/houseboat . . cooling problem for transmissions? Keel coolers . . Motors? Again, keel coolers . . Cost? a couple hundred dollars to a junk yard for the status of having twin engine manuverability . . . Never say never, never say it can't be done . . Oh, and dependability on my last Ford unit? 10+ years, 24/7, pushing freight, harvesting oysters, etc., etc., etc. . . . . . . I love marine design/applications . . . .
     
  5. saeble
    Joined: Mar 2005
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    saeble Junior Member

    wow, talk about thread necromancy :)

    this is a common sort of reaction sadly

    when you question the ways, you often get stomped on and derided

    in any case its good to see there's a few others who like to take the same approach I do. :)

    I'm still messin' about with my design, unfortunately life keeps getting in the way of my plans, so I haven't got much past initial drafting for CNC cutting the hull parts.
     
  6. SamSam
    Joined: Feb 2005
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    SamSam Senior Member

    Excellent! I've often heard of old time stuff where the families car or truck engines were used to keep the boat fishing. You could always get a ride to the store but you had to have the boat going to make the money to take to the store.

    Will-go-fast, did you have any problems with the 'no thrust bearing' thing that is always brought up? Did you use an application where that didn't matter?

    I think one of the big differences between vehicle and marine applications is overflow of the carb if the float gets stuck. Somehow marine aps take care of the problem, maybe it flows back to the tank instead of on top of the engine and into the bilge. Whatever it is, I'm sure it's covered somewhere in this section of the forum (DIY Marinizing).

    [​IMG]

    http://www.oldboatsonthebrain.com/

    .
     
  7. whitepointer23

    whitepointer23 Previous Member

    what gonzo says about auto engines exploding if you look at them and having no thrust bearings and not getting on the plane is a complete load of rubbish, the man sits on his computer waiting to pounce on anyone that has a different idea. a friend of mine who is now in his 80's has just launched another boat with a ford engine and auto trans. he fits a crossmember with a thrust bearing to take the thrust and from there he uses a shortened auto tailshaft to the gearbox so he can fit the rubber mounts that came with the engine, the props are fairly large to give it speed in reverse and uses 1st gear to get out of the marina and then it drops into 2nd and third when he accelerates. all his boats are 30 to 35 foot atkin designs, and they perform very well and never give any trouble. the oil coolers he makes himself with 2 lengths of different diameter copper pipe. this man has built over 120 petrol inboards over a 65 year period and never had a fire or explosion. i would like to see you tell him he is dangerous or doesn't know what he is doing gonzo. he also makes his own heat exchangers with copper pipes about 12 foot long, the inside has the coolant and the outside has the salt water, as for the comment that its only good for low speed, his boats that i have been in cruise all day at 15 to 24 knots.
     
  8. tom kane
    Joined: Nov 2003
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    tom kane Senior Member

    Some boaties need to have someone holding their hand and telling them what to do all of the time and don`t want to use their own skills and imagination or research about a suggestion made, that they don`t know anything about.
    No progress can be made with that attitude in boat safety or anything else. The Law is seldom always right and experts prefer to safely copy everyone else in case they make a mistake. Or upset a Manufacturer.
    Take the thread Safe Remote Fuel System for Boats for instance. It is always Buyer Beware with anything you buy and a lot of mi-information in the selling of a product.
     
  9. whitepointer23

    whitepointer23 Previous Member

    another advantage of using an auto transmission is you don't need an anchor, when you find your fishing spot you just shift it into park.
     
  10. powerabout
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    powerabout Senior Member

    Brilliant!!
     
  11. EvilBoater
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    EvilBoater New Member

    One person has said that Automotive Transmissions do not have thrust bearings. This is a Complete and total falsehood. Automotive transmissions have thrust bearings, this is what keeps the shafts from punching through the aluminum casing of the transmission assembly, No internal thrust bearings, equals blown transmission! (Have you ever seen a car with a broken U-Joint? I'll bet you didn't see the rear transmission shaft out through the transmission case did you?) ALL transmissions have thrust bearings! Without them, they wouldn't work. The same goes for transfer cases, they'd blow apart without the thrust bearings to keep the shafts inside. Borg-Warner Marine Transmissions, and Borg-Warner car transmissions and transaxles share lots of parts, including thrust bearings, gears, shift forks, many of the parts are interchangable and bear the same part numbers.


    Marine Transmissions use both internal and external thrust bearings because of the length of the prop shaft, and the fact that props shafts are not wedged into a differential to keep them from shooting backwards.

    A car automatic transmission can be used, You need a High Stall torque converter, a good cooler to cool the transmission fluid, a street/strip tranny rebuild kit, a trans brake (so that you can stop the transmission rotation to shift into reverse without doing damage) and a way to be able to drain the transmission fluid and change the filter when necessary. You will probably need to have a drive shaft yoke made to accommodate the standard marine prop shaft couplings, and external thrust bearings and keepers to keep the prop shaft from moving too much under a load.

    Note: Most of the smaller lobster boats I have worked on have car engines, with car automatic transmissions most without making the investment to convert the power train to marine grade components at all, sometimes it works just fine, sometimes they regret that salvage yard engine and transmission they picked up on the cheap.
     
  12. tom kane
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    tom kane Senior Member

    My first boat had a three speed auto transmission, I would like to try a modern automatic 9 speed transmission.
     
  13. powerabout
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    powerabout Senior Member

    problem is most are electronic controlled so a custom controller will be required
     
  14. DCockey
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    DCockey Senior Member

    What benefits would you expect from the 9 speed transmission?
     

  15. tom kane
    Joined: Nov 2003
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    Location: Hamilton.New Zealand.

    tom kane Senior Member

    automobile transmission,why not?

    With the gearboxes I used in my boats I could try a variety of propellor pitches and diameter and run them fast or slow in subsurface or surface mode. A three speed box was not enough but with multi gears there is more choice.Maths never works out optimum performance but only gives a theory about what might be. How many times have design forcasts failed to deliver what is possible or what the customer asked for. I used to make my own fablricated props from high strength sleel and running at different speeds was most enlightning. The choice of running a motor on a boat fast and the prop slow is good in tricky seas and shallow water where a grounding would stall a motor at the wrong time. Driving a single blade propeller (Auger) in the shallows was another experiment,so a choice of gears was essential.
    Messing about with to many controls on a pleasure boat is not realy fun but easy control is.
     
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