View Full Version : Heres a crazy idea
If problems exist in a jet boat when rpms reach past a said redline. Why are gears not added in line? if a large gear was added to the engine side and a smaller gear was added to the pump side then it would make the pump move faster maybe twice as fast depending on if the gear was twice the size of the other. If the pump spins faster then it will move more water, at the same time making the boat move faster. Granted you will loose a little torque along the way. Can anyone tell me why this was not done in the past or if has what are some sources I can refer to.
Read this and the next page (http://www.cpperformance.com/TechTips/impeller.htm)
[ June 22, 2003, 10:09 AM: Message edited by: Hal ]
cal***boat
06-22-2003, 02:17 PM
It was tried many years ago with a casale gear box bolted up to the pump by Bruce Halloway from GTH Performace in Pacheco, Cal and it did not work out that good.
That's all i know about the subject.
jlnorthrup122
06-22-2003, 07:34 PM
I have a concept jet drive design that optimizes this cocept however I am to damn poor to build one and I need more engineering it before I would run it. Don't ask for details I am to topseret. pig_flyi
victorfb
06-23-2003, 10:03 PM
ive had this same thought run through my mind a while back. thinking if you like the way your boat performs through its rmp range now, why not be able to install a gear venders gear splitter which reduces rpm by 22% ? lets say you are running 60 mph at 4700rpm, if you can shift a gearsplitter it would bring that rpm down to about 3650 rpm. but maintaining that speed is the question. it seems that 3650 rpm is still in a good range to keep that torque high enough. but im sure many (smart) engine and boat builders have allready thought about it and tested it. but its still fun to teas the brain about it.
victorfb
06-23-2003, 10:06 PM
by the way... Gear venders has not yet tried it nor have they heard anyone else trying it as of yet.
I firmly believe that a lot of things get swept under the rug by people thinking things have been tried already. If I was a pump manufacturer I would seriously look at building this technology into the pump. It would be more efficient and save gas. Seems like everyone would be buying those pumps instead of the ones using the current technology.
After all I believe jlnorthrup has tapped into the very essence of this technology and created the next generation jet pump, but he is broke and Top Secret. :D
victorfb
06-23-2003, 10:20 PM
you may be very right about that. like i said... gear venders has not yet tried it nor have they heard of anyone trying it with thier product. a gear venders gear splitter (if you dont allready know) is basically a 2 spead automatic tranny and can be shifted at any spead and under any load. (even full load) and they are a compact self contained unit. and at 22% gear splitting it seems it would be a great advantage. i wish i had the three grand for the splitter i would try it. :)
do they have a website if so whats the address? Also I thought of a great way to fund it. Everyone on the board pitches in some cash and we all descide what boat to stick it on to see if it works or we just get the company really interested to see if it works then whooola they just cornered a new market and we all win.
victorfb
06-23-2003, 11:26 PM
gearvendors.com
when i talked to them about it they said it wasnt a large enough market i believe. for THEM to try it. but for someone to get one and do thier own install, well thats a diferant story. i would love to but i have an 18' boat and the motor would have to be set further forward to acommidate the splitter unit, and i would think the wieght distribution on such a small boat not desighned for it would be a huge dissadvantage compared to the advantage of having the splitter. but then again, i really dont know. i would think that a 21' hull would be a better choice. not to say i wouldnt try it with mine just to see.
why not just keep the automatic transmission hooked to the motor and connect the shaft of the transmission to the pump via a power takeoff. Much cheaper and can be found in a junk yard.
victorfb
06-24-2003, 08:25 AM
the gear vendors splitter is about 12" long. an automatic trans is much longer. you would need to move the engine very far forward to be able to connect the entire system. unless you have a very large boat i dont see were the gain would be. too much wieght distribution toward the front of the boat. some hulls were desighned that way of course but they are tournament ski boats and such, not jet boats. i suppose you could solidly mount a clutch or empty and welded torque converter, but that even more wieght. yes useing a complete automatic tranny might be cheaper but alot of unwanted wieght. not to mention the size of the tranny itself.
How about if you turn the engine around and use a 4 wheel drive transfer case facing forward keeping the engine weight in the back of the boat then bring the shaft back under the motor and attach it to the pump. Just a thought.
Frosty_pop
06-24-2003, 05:05 PM
dgie:
How about if you turn the engine around and use a 4 wheel drive transfer case facing forward keeping the engine weight in the back of the boat then bring the shaft back under the motor and attach it to the pump. Just a thought. Sounds like a V-Drive.......
right, but with a jet pump
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