hey POPS1 have you disappeared

[LVjetboy]

"The action of an impeller is the same as a propeller. The impeller is just enclosed in a housing."
Impellers and propellers have a lot in common. How they move the boat not entirely the same. With a propeller, forward thrust is transmitted soley through the thrust bearing. With an impeller, part of the thrust is transmitted through the bearing the rest through the pump housing.
"I wish someone would figure it out..."
Someone already has. As usual, not everyone's paying attention. For those not paying attention...we can debate it forever.
"I said, pick up a fire hose and point it at a wall and see if it pushes you back..."
Yep you said that. And the answer's still no. The wall does not push you back. The wall has nothing to do with thrust. If you still choose to believe that your choice. But don't claim the answer's not known and you wish someone would figure it out. Because it is known, someone figured it out long ago and no thrust comes from the wall. You're just not listening. Is that clear enough?
However, a fire hose is a good example of thrust from water acceleration.
Does a fire hose nozzle have a propeller or impeller? Does a fire hose nozzle have a thrust bearing? So then, how can a fire hose nozzle produce thrust even if not pointed at a wall?
The amazing field of physics who would've known?
jer

[OkieDave]

I always thought the forward motion was caused by me pushing forward on the gas peddle. Sort of like when I used to throw the tow rope to my girlfriend in the boat and tell her to sit in her seat and pull on the rope to pull the boat backward off the trailer. she tried it.

[Jet Hydro]

Jer you can be such a "jack ass" at time`s!
I never said the wall would push you back now did I?
I did say the "HOSE" Would because of the pressure that it`s under at the time you point it at a wall. DUH!!!!!!!!!
Try it some time, then get back to me and tell me that it didn't.
I know it will "Been There Done That!"
May not be the same thing as a jet boat pump but it will push back when pointed close at a wall.
Does a fire hose nozzle have a propeller or impeller? Does a fire hose nozzle have a thrust bearing?
No they just make their own water and pressure...DUH
Why do you think they hook a hose from the truck to the fire plug, then the house you use is hooked to the truck with a nozzle on it? doesn't have much to do with jet boats but YES they do have a impeller and a thrust bearing.
Now "Jack ass" being that you called me out to play, you need to read my post a little better. I never claimed to "know it" or "any of it" I said that`s why "I leave it to my pump guy" didn't I?
Now "go-a-way" and troll someone else. I don't like the way you play. I`m going to take my ball and go home.

[pops1]

Originally posted by LVjetboy
"The action of an impeller is the same as a propeller. The impeller is just enclosed in a housing."
Impellers and propellers have a lot in common. How they move the boat not entirely the same. With a propeller, forward thrust is transmitted soley through the thrust bearing. With an impeller, part of the thrust is transmitted through the bearing the rest through the pump housing.
"I wish someone would figure it out..."
Someone already has. As usual, not everyone's paying attention. For those not paying attention...we can debate it forever.
"I said, pick up a fire hose and point it at a wall and see if it pushes you back..."
Yep you said that. And the answer's still no. The wall does not push you back. The wall has nothing to do with thrust. If you still choose to believe that your choice. But don't claim the answer's not known and you wish someone would figure it out. Because it is known, someone figured it out long ago and no thrust comes from the wall. You're just not listening. Is that clear enough?
However, a fire hose is a good example of thrust from water acceleration.
Does a fire hose nozzle have a propeller or impeller? Does a fire hose nozzle have a thrust bearing? So then, how can a fire hose nozzle produce thrust even if not pointed at a wall?
The amazing field of physics who would've known?
jer I brought this point out for you to think on-
Each Impeller design has both a attack rate, flow rate, ride duration and thrust angle. Much like a propeller uses bite, cup, & pitch. Each design has or is directed at a specific volumn of output
with a specific H/P & Torque Range.
As noted above the forward pull is always understated in concepts for some reason when it comes to jets. Thats all!

[OMEGA_BUBBLE_JET]

pops1, other than the obvious fact that the aggressor impeller has a more 'aggressive' pitch isn't the surface of the blade slightly concave?
Jer what effect would this have on the water moving over the blade???
I find this all to be very informative. thanks for all the info pops.
Omega

[jet4fun]

i didnt read through the other posts so someone may have already said something like this... but if you have ever held the nozzle of a fire hose or any high velocity nozzle you will figure out how a jet boat is propelled. there is something called nozzle reaction which is basically the force of the water coming out of the nozzle pushing back at you. that force is enough to push someone over. i cant even hold a 2 1/2 inch line by myself if i am running it full bore. it takes 2-3 people.
that same force is what pushes a jet boat forward. the nozzle reaction on steroids... that is what makes the place diverter work, when you put the nozzle up you are changing the thrust angle which basically uses the back of the boat as a pivot point which lifts the front of the boat up and frees it up which causes an increase in speed because of less wetted surface of the boat. that is why usually if you put the diverter up too far it will start slowing the boat back down again because too much will cause the ass of the boat to basically shovel or drag into the water.
if the pulling of the impeller on the water was what pulled the boat forward then how do you explain the fact that when you are running across the water the intake in front of the impeller has a positive amount of water pressure inside it keeping the impeller loaded.
if the impeller was pulling then there would have to be a vacuum of water in the intake pulling more water in, causing the boat to move forward... ummmm that doesnt work, that causes cavitation... which we all know doesnt work
make sense???

[cyclone]

Originally posted by jet4fun
i didnt read through the other posts so someone may have already said something like this... but if you have ever held the nozzle of a fire hose or any high velocity nozzle you will figure out how a jet boat is propelled. there is something called nozzle reaction which is basically the force of the water coming out of the nozzle pushing back at you. that force is enough to push someone over. i cant even hold a 2 1/2 inch line by myself if i am running it full bore. it takes 2-3 people.
that same force is what pushes a jet boat forward. the nozzle reaction on steroids... that is what makes the place diverter work, when you put the nozzle up you are changing the thrust angle which basically uses the back of the boat as a pivot point which lifts the front of the boat up and frees it up which causes an increase in speed because of less wetted surface of the boat. that is why usually if you put the diverter up too far it will start slowing the boat back down again because too much will cause the ass of the boat to basically shovel or drag into the water.
if the pulling of the impeller on the water was what pulled the boat forward then how do you explain the fact that when you are running across the water the intake in front of the impeller has a positive amount of water pressure inside it keeping the impeller loaded.
if the impeller was pulling then there would have to be a vacuum of water in the intake pulling more water in, causing the boat to move forward... ummmm that doesnt work, that causes cavitation... which we all know doesnt work
make sense???
no that is a great question. i'd like to hear more about this "nozzle reaction."

[pops1]

Originally posted by OMEGA_BUBBLE_JET
pops1, other than the obvious fact that the aggressor impeller has a more 'aggressive' pitch isn't the surface of the blade slightly concave?
Jer what effect would this have on the water moving over the blade???
I find this all to be very informative. thanks for all the info pops.
Omega Yes! It also has a longer duration of ride, larger passages, a flatter thrust side.
Its mis-leading when you show a detailed impeller. #1 thy always polish the face of the vane. Thats the non working side of the Impeller- Yet most go "OOO" and "AAAA"
The side you see has so little to do with the Impellers performance. Its all in what you do not see. Yet guy's pay the man $250.00 for OOOO & AAAAs
#2 You cannot make a racehorse out of a camel. If the functions are not there, you will not grind them in.
The same with bowls and all other parts. One clown has a write up on bowls on his web site. It is the funnest BS lack of knowledge piece I have ever seen.
Use your eye's and head and you will learn. Remember the winners don't buy if it don't work.

[jet4fun]

Originally posted by cyclone
no that is a great question. i'd like to hear more about this "nozzle reaction."
ummm, its like this... you hook tab A into slot B which goes into fold C. then you wire up the flux capacitor reverse polarity in series with the bada bing. next thing you know you have a 100 mhp jet boat

[OMEGA_BUBBLE_JET]

Originally posted by pops1
Yes! It also has a longer duration of ride, larger passages, a flatter thrust side.
Its mis-leading when you show a detailed impeller. #1 thy always polish the face of the vane. Thats the non working side of the Impeller- Yet most go "OOO" and "AAAA"
The side you see has so little to do with the Impellers performance. Its all in what you do not see. Yet guy's pay the man $250.00 for OOOO & AAAAs
#2 You cannot make a racehorse out of a camel. If the functions are not there, you will not grind them in.
The same with bowls and all other parts. One clown has a write up on bowls on his web site. It is the funnest BS lack of knowledge piece I have ever seen.
Use your eye's and head and you will learn. Remember the winners don't buy if it don't work.
thanks for the reply pops Jer care to answer my question on what effect the contour of the blade has on its ability to 'pull' water into it
love the comment about not making a camel into a racehorse but I think this one works better for the given scenario:
'you can't polish a terd'
Omega