Automobile Transmission, why not?

The transmission shifts VERY FAST thru the 1 st gear until the load on the prop puts the same amount of load on the tranny as a car rapidly accelerating.

A transmission does not KNOW OR CARE if it spinning a tire or a boat prop or a airplane prop or a 100 hp water pump in a farm field.

All HAVE been done. Some are more sucessfull than others.

 

you put it in gear and it moves, pretty simple really. the trick is to set the prop size to second gear, that gives a good reverse as well. you have a shaft lock with the park pall so spinning in neutral is not a problem. i don't understand why you don't get it. it is a low budget idea that works , its not to compete with a proper marine setup. i am thinking of putting a 400 hp cummins and 13 speed road ranger in my boat then i can use the jakes to stop it surfing down waves.

 

I thought a "Jake Brake" worked on engine compression. Why is a transmission needed?

 

An auto tranny works by pressures oposing another. Governor pressure increases as the shaft increases RPM. when it exeeds throttle pressure (depending on how big your boot it ) it will shift. Press the throttle more and it will shift down again.

When you boot a car the modulator comes in with max line pressure to hold all the clutches tight so they dont slip. If you give it full throttle it will kick down over riding the governor pressure, so that HAS to be disconnected

Now do you think it will work?

 

sorry, i was trying to be funny.

 

yes i do think it will work because as i said i have driven boats with them and they were mainly used in 2 or reverse but did drop into top if the boat was going fast enough. kick down cables were still connected to maintain hyd pressure. why don't you put one in an old boat and try it frosty.

 

Jake brake, That was a good one, lol

 

It does actually work.
My brother in - law installed 2x 307 chevy into a 29 ft scarab hull complete with transmissions.

 

Love to see some photos
what drives were used?

 

I would also like to see photos of that.

How much did the engine mounts need to be moved forward to allow space for the transmissions? Did he redo the back seat & engine compartment on the 29 to fit?

 

I don`t have any photos , sorry.

Vince ( brother in law ) has moved on since then , it was over 20 years ago ...He had a thriving business importing chevy engines and V8 performance parts from the US .... the blocks came from Mexico....the business was called Superchev" and local petrol heads all went to him for their stuff....he has moved on since then ...is now into trucks and truck engines.

It was a fun boat , it had air craft landing lights set flush with the hull...
It does work.......

 

Compared to a sterndrive..about 3 feet

 

There is only about one foot or 18" between stock engines and the back seat on the 29 scarab. He must have redone the sunpad, bench seat and maybe moved the engine bulkhead forward I think. Too bad there aren't photos or a video of it going up on plane and shifting.

 

I don`t know if this helps any , but have a read anyway...

http://www.google.com.au/url?sa=t&s...sg=AFQjCNHrPH0INQj02CJcWddgtQ06BUThkg&cad=rja

 

It would have been a oz built 29
I had a few customers with them some with 260 and some with 330/370trs's
They were built as bad as the ones in the US so light and went ok