need to find small transmission

[fishon91]

im designing a boat(just in very early design stage) powered by twin vanguard 35's. i need to find a transmission that has only a reverse-nuetral-forward and about a 1.4:1 ratio in forward, maybe 1.7:1 in reverse.
how do i go about finding something like this? i have no experience in regular boat design. my whole life has revolved around mud motors, so i know not much about inboards or even outboards.
this is just a project i am designing for a buils years down the road and thanks for any help.

[whitepointer23]

hello fishon, check out hurth transmissions. they have small models, don't know why you want different ratios for forward and reverse though.

[CDK]

The European subsidiary of TwinDisc specializes in small gearboxes:

http://www.technodrive.it/english/index-eng.htm

[fishon91]

thanks yall, and sorry for bringing back an abandoned thread.. i dunno why i didnt respond..
id want a lower revers gear for power, lower rpms and more power would be more necessary in reverse. this is a mudboat type design so reverse would be mostly necessary for helping get out of sticky situations. i thought reverse was typically a lower gear in most transmissions.

[whitepointer23]

Originally Posted by fishon91

thanks yall, and sorry for bringing back an abandoned thread.. i dunno why i didnt respond..
id want a lower revers gear for power, lower rpms and more power would be more necessary in reverse. this is a mudboat type design so reverse would be mostly necessary for helping get out of sticky situations. i thought reverse was typically a lower gear in most transmissions.

not in marine trans. r&f are same ratio. you might have to use a car transmission for what you want. i would have thought correct prop selection would give the result you need with out having to use odd ratios.

[EvilBoater]

Most of the small Transmissions I that have seen are limited to the 16 H.P. range. (comet makes an F-N-R gear box, Glen-L has a F-N-R design for a small gas engine as well) I do have a design for a chain and belt driven transmission that utilizes electric clutches from a lawn tractor to select from F-N-R as far as the "Gear Ratio" this all depends on the size of the pulleys. I have never tested it with an engine bigger than 16 H.P. BUT I would imagine if you could get strong enough and thick enough belts, it might handle a lot more H.P. OR you could try using a 4x4 transaxle out of a 1970 Dodge Ramcharger One ton OR a small 3 speed transmisson out of a chevy vega Rear wheel drive. (Clutching would be your only problem with the transmission and transaxle) If you want the pulley set up plans contact me and you can have them.

[michael pierzga]

Go to a marine junk yard. Marine engine shops have used gearbox's stacked up like cord wood. See what they have, research its suitability, then buy one . A good price would be 10 cents on the dollar. Transmissions are durable and rebuildable.