Flywheel or Flexplate

[Taylorman]

http://i22.photobucket.com/albums/b334/vidrinek/Boat/DCP_5962.jpg

[Sleek-Jet]

Flexplate.... I think.... :D Looks pretty beefy though, SFI maybe???

[DelawareDave]

That is a flex-plate. A flywheel would have a smooth face where a clutch disk would engage.

[1899]

I was kinda wondering myself if we can mount a auto tranny flywheel on the boat instead of a heavy manual flywheel. Is this possible? Are there any advantages?

[AZKC]

I've allways used flexplates, and don't think I've seen a flywheel on a boat. :idea:

[1899]

Well mine deffinatly has a heavy flywheel behind the olds 455. Didint know if it was somthing required or not. I have a flex plate off a car i could try to install.

[IMPATIENT 1]

you would think a flex plate would be less rotating mass weight. only thing either are good for on a jet is starting it.go flex plate.

[SmokinLowriderSS]

The flexplate will let it wind up a bit quicker, useful on a jet boat, beyond that, not much reason to get a preference. Well, there IS the 40 or so pound weight savings ....

[Nucking futs]

You can run either one. I hear the flexplate will get your R's up quicker, but the flywheel is easier on the engine in the long run becuase the weight is allowing the engine to spin with less effort.
Post this over in gearheads and More will chime in on this. there was a good thread on it awile ago but I can't seem to find it at the moment....
If you have a crank with no rods, Imagine taking a flexplate, spin it and see how long it will spin. Now do the same with a flywheel and see how much longer it spins.Yes its more mass, but once you get it there, it works easier.
Just my .02
Tim

[TIMINATOR]

Use an aluminum flywheel! It is light and it won't flex when the starter engages and rip the teeth off. If you don't have a nasty motor, either will work. A flexplate in a car is no problem cause the torque convertor is bolted to it and provides rigidity for the ring gear. The fool that I bought my last alum. flywheel from at a local swap meet laughed to his friends that he screwed me because the flywheel needed to be surfaced and someone told him that it couldn't be done,(wrong again). He "got" me for $10.00 on it. Its still in the boat 4 years later. Yup, I was "got". TIMINATOR

[Moneypitt]

This subject has been bounced off of just about every builders opinion. I have stated before, and I'll say it again. The PS boat is 13.1;1. Right now, because it has a 427 crank in it, we're using an aftermarket aluminum flexplate. This one lost the ring gear the first time I winged it on the trailer. I fixed it and we used it for awhile in the early 90s. And again with this set up. However, we have also used, without any problems whatsoever, a bone stock GM external flexplate on the 454 cranked motors. Never had any problems with starter engagement using a stock GM starter with a P/G nose. I have seen so many other racers fail to start using the high dollar aftermarket flywheels/flexplates and the high dollar aftermarket mini/hi torq starters. It is true that a converter adds alot of strength to the flexplate, but in a boat it is just a starter ring, period. There is no power suppied through the plate. Considering the mass you have to move, any weight saving on a rotating assembly is a good thing. Also, you're not trying to ease a vehicle from a dead stop while letting the clutch out, so you don't need the momentum of a heavy flywheel to prevent stalling the engine. Rotating mass = less is better. The most important thing in a starter/starter ring engagement is a stout battery to spin it up without laboring. The rest is all good.........Now if you're running a MOPAR, you have to use a flywheel because the starter ring on the automatics is on the converter, not the flexplate............MP

[Duane HTP]

Flex plate is the recommended way to go. Just don't go to your local salvage or dealer and buy a regular car flex plate. Like said above they can Flex without the converter bolted to them. This usually results in starter problems sooner or later. Buy a good SFI or the thicker flexplate that is used in the patrol cars. A lot of people don't realize that a starter works harder in a jet boat than it does a car because it not only has to start the engine, it has to turn the pump shaft, the drive line, loaded impeller and move water all at the same time. Running a flex plate in a jet boat is not harder on the engine than the flywheel because the pump shaft, drive line, and impeller serve as the flywheel. Just use a GOOD flex plate. Pioneer makes a good thick one at a reasonable price for most applications.

[396_WAYS_TO_SPIT]

Use an aluminum flywheel! It is light and it won't flex when the starter engages and rip the teeth off. If you don't have a nasty motor, either will work. A flexplate in a car is no problem cause the torque convertor is bolted to it and provides rigidity for the ring gear. The fool that I bought my last alum. flywheel from at a local swap meet laughed to his friends that he screwed me because the flywheel needed to be surfaced and someone told him that it couldn't be done,(wrong again). He "got" me for $10.00 on it. Its still in the boat 4 years later. Yup, I was "got". TIMINATOR
Sounds like you got him;) Thats a smoking deal on an aluminum flywheel.

[SmokinLowriderSS]

Use an aluminum flywheel! It is light and it won't flex when the starter engages and rip the teeth off. If you don't have a nasty motor, either will work. A flexplate in a car is no problem cause the torque convertor is bolted to it and provides rigidity for the ring gear. The fool that I bought my last alum. flywheel from at a local swap meet laughed to his friends that he screwed me because the flywheel needed to be surfaced and someone told him that it couldn't be done,(wrong again). He "got" me for $10.00 on it. Its still in the boat 4 years later. Yup, I was "got". TIMINATOR
Yep, can't complain about THAT deal. LOL :rollside:

[Taylorman]

Interested in doubling your money on that flywheel?

[Klass Klown]

This subject has been bounced off of just about every builders opinion. I have stated before, and I'll say it again. The PS boat is 13.1;1. Right now, because it has a 427 crank in it, we're using an aftermarket aluminum flexplate. This one lost the ring gear the first time I winged it on the trailer. I fixed it and we used it for awhile in the early 90s. And again with this set up. However, we have also used, without any problems whatsoever, a bone stock GM external flexplate on the 454 cranked motors. Never had any problems with starter engagement using a stock GM starter with a P/G nose. I have seen so many other racers fail to start using the high dollar aftermarket flywheels/flexplates and the high dollar aftermarket mini/hi torq starters. It is true that a converter adds alot of strength to the flexplate, but in a boat it is just a starter ring, period. There is no power suppied through the plate. Considering the mass you have to move, any weight saving on a rotating assembly is a good thing. Also, you're not trying to ease a vehicle from a dead stop while letting the clutch out, so you don't need the momentum of a heavy flywheel to prevent stalling the engine. Rotating mass = less is better. The most important thing in a starter/starter ring engagement is a stout battery to spin it up without laboring. The rest is all good.........Now if you're running a MOPAR, you have to use a flywheel because the starter ring on the automatics is on the converter, not the flexplate............MP So what you are saying is the extra weight (in the form of a flywheel) would not help you keep the momentum(rpm) up in the motor into a turn?? I understand your point yet do you mine?

[wsuwrhr]

Now if you're running a MOPAR, you have to use a flywheel because the starter ring on the automatics is on the converter, not the flexplate............MP
Damn Mopars.
Brian

[Moneypitt]

So what you are saying is the extra weight (in the form of a flywheel) would not help you keep the momentum(rpm) up in the motor into a turn?? I understand your point yet do you mine?
What type of boat, and what type of turn.......Vdrives have NO problem keeping the Rs up around a turn, IF the driver is on the right pedal while he's on the left pedal. However, the west coast single pin turns usually require backing off and hitting the plate. Then getting the Rs back up is the heavy flywheel issue, more mass= slower Reving. As I said, we're not talking about letting out a clutch to move a vehicle. Quite frankly, I can see no reason what so ever to add additional weight to a rotating assy in a boat, regardless of the drive type.........MP

[Klass Klown]

You obviously NO NOTHING about torsional harmonics. Case proven.. :p

[Moneypitt]

You obviously KNOW nothing about elementry school english........torsional harmonics.......hmmmmmmm, lets see a harmonic is a vibration, so the more weight you spin up has more harmonics? I didn't think vibration was something you wanted in a rotating mass. I remember the Ford Courier trucks, so under powered they had to put a 40 lb flywheel in them to keep from stalling the motor when you let the clutch out......Now, explain to me what advantage this additional weight has on a rotating mass in a boat. MP

[396_WAYS_TO_SPIT]

well I can just say that I run a "heavy" flywheel in my boats and they never let me down;) Im sure the flexplate would be better but "if it aint broke, then dont fix it" ;);)
MP, you do have a point in your last post;)

[Klass Klown]

You obviously KNOW nothing about elementry school english........torsional harmonics.......hmmmmmmm, lets see a harmonic is a vibration, so the more weight you spin up has more harmonics? I didn't think vibration was something you wanted in a rotating mass. I remember the Ford Courier trucks, so under powered they had to put a 40 lb flywheel in them to keep from stalling the motor when you let the clutch out......Now, explain to me what advantage this additional weight has on a rotating mass in a boat. MP
Ok M.P, let's see have you ever seen a one lung very very old motor with a FLY WHEEL ( hence the name)??? With more rotating weight ( once it is spinning) ( not perpetual motion) let's say in a car.. You leave the line at let's say , well, you load the clutch or trans brake up to 6500 rpm, Now a heavy car which could use the extra rotating mass coupled to the tranny will leave and lug the motor to say 5000 rpm depending on tire size, efficiancy of the set up tire spin etc. would benefit with the heavier rotating mass as opposed to a lighter flex plate.. Would you agree???? So in a boat the question is once the rpm is attained would a heavier flywheel help or hinder?? Without the extra weight it would pull the motor down quicker Under a load correct? So exactly how much the extra weight hinder's the overall acceleration is what's debateable... Can you HONESTLY TELL ME YOU KNOW BASED ON TIME SLIP OR LAP TIME?? Your post is very DEBATEABLE!!! And I honestly think you are chartering in grounds Unbeknown to you!!!!!!!!!!

[Klass Klown]

One more thing, you take the pro stock class in N.H.R.A they run lenco's, Liberty's etc, Do you not think in the most Competitive class in N.H.R.A if rotating weight was such the issue i.e. above they would be running ---oh let's say an automatic HA HA lol Lmao Guess again!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!! I guess boats are more of a science than prostock cars!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! ENOUGH SAID

[Moneypitt]

And I honestly think you are chartering in grounds Unbeknown to you!!!!!!!!!!
Ah, the key word here is Ground. In both your examples you are refering to moving a mass on the ground. A direct conection to the ground, flywheels, clutches, driveshafts, and of course gears and tires. IMO,you can not compare the requirements of automotive performance and boat performance, nor can you compare the rotating mass required to bring a boat out of a corner with the inertia required to launch a vehicle. You mentioned the need to maintain Rs through a corner, but you forget the massive power to weight ratio advantage in a boat. With hulls weighing around 400 lbs bare, and everything added is primarily for purpulsion, a boat just doesn't need the rotating mass. In fact, having a motor that will lay down suddenly when you want it to can be a tremendous advantage. Example: Down the front straight, green flag start at about 60 MPH and 5/16ths of a mile into the first turn. The motor goes to 7500, the speed is around 100 as you come to the turn pin. You're on the inside lane with 5 or 6 boats outside you. You drive the boat as deep into the turn as possible, allowing for distance to break your speed down to almost nothing to do a u turn in a boat length, and stay in your 10 foot lane, on BOTH sides of the pin. IF your motor wants to continue spining because of the "rotating mass", you are not going to be assisted in slowing by the reduced speed of your prop, and would have to lift way too early to keep up with the boats on the outside, that can keep their Rs up as they turn much wider. Once you lose the lane, or fall behind the pack you are in for a rough ride for the rest of the race, even if you have the power to stay with the pack you are just far enough behind to never find any good water. By the same token, you must be able to re rev the motor like turning on a light switch, or once again, you will fall back. Please remember these boats are geared and proped to come to RPMs right now. And again I say, in a boat, there is no reason to add additional weight to a rotating mass, UNLESS the combination is way under powered for what it is trying to pull, and even then it would only apply while initial engagemeent is taking place. Once the boat is in motion under power it will get drier and drier and require less inertia to maintain RPMs. I think we are trying to compare apples to oranges.....Weight issues aside, a rigid flywheel does have it's advantages in a boat while starting, IF, flexplates are flexing away from the starter gear. As I said initially, I have ran stock GM flexplates with stock GM starters, cranking a 13.1:1 motor with 37* degrees in a locked mag without any problems for years. I try very hard to make the rotating mass as light as possible, and it revs, click on, click off, click on, click off........MP

[Squirtin Thunder]

Cars like heavy fly wheels !!! :cool:
There are lots of good points, but I will make one also. The FLYWHEEL is heavy, much harder to slow down, FLEXPLATE is light much easier to slow down. And the same with acceleration. Now if you are trying to beat the next guy out of the corner you want the snappiest throttle responce as possible, but when catching air because of rough water you want to drop Rs as quick as possible to protect parts. In NHRA, IHRA and many more drag racing series it really does not matter being the rubber is your breaking point and basically stays loaded to a degree even when you haze the tires. In Off-Shore racing they have an extra guy to run the throttles and they still have problems. In a Jet Boat you will destroy a impeller with a heavy Flywheel, because you can not slow the rpms quick enough, 396 has a perfect example of that somewhere. By loading and unloading hard at high rpm, 5500 and above they will crack and break.

[Klass Klown]

And I honestly think you are chartering in grounds Unbeknown to you!!!!!!!!!!
Ah, the key word here is Ground. In both your examples you are refering to moving a mass on the ground. A direct conection to the ground, flywheels, clutches, driveshafts, and of course gears and tires. IMO,you can not compare the requirements of automotive performance and boat performance, nor can you compare the rotating mass required to bring a boat out of a corner with the inertia required to launch a vehicle. You mentioned the need to maintain Rs through a corner, but you forget the massive power to weight ratio advantage in a boat. With hulls weighing around 400 lbs bare, and everything added is primarily for purpulsion, a boat just doesn't need the rotating mass. In fact, having a motor that will lay down suddenly when you want it to can be a tremendous advantage. Example: Down the front straight, green flag start at about 60 MPH and 5/16ths of a mile into the first turn. The motor goes to 7500, the speed is around 100 as you come to the turn pin. You're on the inside lane with 5 or 6 boats outside you. You drive the boat as deep into the turn as possible, allowing for distance to break your speed down to almost nothing to do a u turn in a boat length, and stay in your 10 foot lane, on BOTH sides of the pin. IF your motor wants to continue spining because of the "rotating mass", you are not going to be assisted in slowing by the reduced speed of your prop, and would have to lift way too early to keep up with the boats on the outside, that can keep their Rs up as they turn much wider. Once you lose the lane, or fall behind the pack you are in for a rough ride for the rest of the race, even if you have the power to stay with the pack you are just far enough behind to never find any good water. By the same token, you must be able to re rev the motor like turning on a light switch, or once again, you will fall back. Please remember these boats are geared and proped to come to RPMs right now. And again I say, in a boat, there is no reason to add additional weight to a rotating mass, UNLESS the combination is way under powered for what it is trying to pull, and even then it would only apply while initial engagemeent is taking place. Once the boat is in motion under power it will get drier and drier and require less inertia to maintain RPMs. I think we are trying to compare apples to oranges.....Weight issues aside, a rigid flywheel does have it's advantages in a boat while starting, IF, flexplates are flexing away from the starter gear. As I said initially, I have ran stock GM flexplates with stock GM starters, cranking a 13.1:1 motor with 37* degrees in a locked mag without any problems for years. I try very hard to make the rotating mass as light as possible, and it revs, click on, click off, click on, click off........MP
Answer my question have you ever timed a lap using either???????/ We are comparing apples to oranges I just dis agree with some of your advice.. So I would assume you use a 49# crankshaft and aluminum rod's correct?? As well as the longest possible rod length and lightest piston?? Just curious because there are more than one way to skin a cat.

[Moneypitt]

Answer my question have you ever timed a lap using either???????/ We are comparing apples to oranges I just dis agree with some of your advice.. So I would assume you use a 49# crankshaft and aluminum rod's correct?? As well as the longest possible rod length and lightest piston?? Just curious because there are more than one way to skin a cat.
Circle racers do not race the clock, they race each other. Lightest piston, well, they are hollow dome; .250 long, lightest steel rods I can find, (Aluminum rods don't really have the life expectancy we require), and we can't afford 49# crankshafts. When running an apple, IMO lighter is better, and I understand your dis agreement with my advice when driving an orange, but it is only MY opinion, as I stated in the first post, and my opinion works for me as applied to apples. I have driven oranges, have you ever driven an apple? MP
PS: If heavier is better, why were aluminum flywheels created for oranges??

[sleekcrafter]

Bottom line here is that the extra mass has to be accellerated whether rotating or linear, it's all in what your trying to accomplish. IMHO I perfer the lighter mass approach, makes for quicker accelleration period on water.
Sleek

[Klass Klown]

Circle racers do not race the clock, they race each other. Lightest piston, well, they are hollow dome; .250 long, lightest steel rods I can find, (Aluminum rods don't really have the life expectancy we require), and we can't afford 49# crankshafts. When running an apple, IMO lighter is better, and I understand your dis agreement with my advice when driving an orange, but it is only MY opinion, as I stated in the first post, and my opinion works for me as applied to apples. I have driven oranges, have you ever driven an apple? MP
PS: If heavier is better, why were aluminum flywheels created for oranges??
Yes I have, back to my point. I understand your point And agree to a certain extent with your advice I would not completely rule out a flywheel if I were on a budget and i was already in posession of one! As you cannott afford a 49# crank a Titanium rod, you obviously use what you can afford!! Although it has been my experience that does not always get you to the winner's circle!! :rollside:

[Taylorman]

I just wanted to know if i have a flywheel or flexplate guys. Wow this has gotten to deep. Heres my vote, lighter is better in an engine. End of story. You two are giving me a headache.

[Klass Klown]

I just wanted to know if i have a flywheel or flexplate guys. Wow this has gotten to deep. Heres my vote, lighter is better in an engine. End of story. You two are giving me a headache.
Than run the lightest rotating assy. you can buy, light crank,LONG aluminum rod's, Ultra light piston's etc and watch your spring pressure on the seats for your Titanium valves LOL LOL LOL!!!!! :idea:

[Squirtin Thunder]

Yes I have, back to my point. I understand your point And agree to a certain extent with your advice I would not completely rule out a flywheel if I were on a budget and i was already in posession of one! As you cannott afford a 49# crank a Titanium rod, you obviously use what you can afford!! Although it has been my experience that does not always get you to the winner's circle!!
Biography:
Highly competitive at everything
Location:
Palmyra, Virginia
Interests:
Any foorm of racing
Occupation:
Buisness owner
Your Boat:
several :rollside:
PM me your contact info, I'd like to talk to you for a min.
Thanks
Jim

[LakesOnly]

Either can work, the flexplate is probably more popular among the custom built ***boats and a quality flexplate is fine. Personally, I have a lightened aluminum flywheel on mine.
LO

[Klass Klown]

PM me your contact info, I'd like to talk to you for a min.
Thanks
Jim
So is this how it works someone goes against the norm and they're profile is published?? Nice!! send me a P.M and we'll talk......

[SmokinLowriderSS]

Yes I have, back to my point. I understand your point And agree to a certain extent with your advice I would not completely rule out a flywheel if I were on a budget and i was already in posession of one! As you cannott afford a 49# crank a Titanium rod, you obviously use what you can afford!! Although it has been my experience that does not always get you to the winner's circle!! :rollside:
It seems that the general concensus is this : "Either will work just fine 80% of the time, in 90% of the boats out there."
Now, Boats are not cars, even drag boats are not drag cars. Jet drives & ?rop drives have only 1 thing in common with a car's driveline, they have an engine attatched to them, period.
For that other 10% of the boats out there, and the other 20% of the times out there, flexplates and the faster throttle response is important enough to sway a preference tht way. There are times you may actually WANT the engine response to be nearly instantaneous, as described earlier. At those times, 50 pounds of flywheel is a BAD THING.
If you ever actually "detatch" a car from the ground, you are going damn fast & for a ride, and you are no longer "driving".
It is comon to put a boat airborne at speeds as low as 50 MPH. If you do not learn to "pedal" the throttle when you go airborne, you will break parts very soon, gears in a prop and impellers in a jet.
My 454 came with a factory steel flexplate, been flawless for 27 years, not about to change now.

[SmokinLowriderSS]

So is this how it works someone goes against the norm and they're profile is published?? Nice!! send me a P.M and we'll talk......
Well, I just looked, none of it was a secret, you published it for all to see. The "highly competetive at EVERYTHING" was no surprise to me either from the way this thread went.

[Sleek-Jet]

So is this how it works someone goes against the norm and they're profile is published?? Nice!! send me a P.M and we'll talk......
...Actually it would be "their" profile... and this thread wasn't started to be a pissing contest, just someone wanted to know if he had a flexplate or not. :D

[FLYTE RISK]

It seems that the general concensus is this : "Either will work just fine 80% of the time, in 90% of the boats out there."
Now, Boats are not cars, even drag boats are not drag cars. Jet drives & ?rop drives have only 1 thing in common with a car's driveline, they have an engine attatched to them, period.
For that other 10% of the boats out there, and the other 20% of the times out there, flexplates and the faster throttle response is important enough to sway a preference tht way. There are times you may actually WANT the engine response to be nearly instantaneous, as described earlier. At those times, 50 pounds of flywheel is a BAD THING.
If you ever actually "detatch" a car from the ground, you are going damn fast & for a ride, and you are no longer "driving".
It is comon to put a boat airborne at speeds as low as 50 MPH. If you do not learn to "pedal" the throttle when you go airborne, you will break parts very soon, gears in a prop and impellers in a jet.
My 454 came with a factory steel flexplate, been flawless for 27 years, not about to change now.
So with that being said I suppose your rotating assy. is the lightest you could make it as well??? And as far as getting a boat airborne I dont think any boat, motor, outdrive, pump,v-drive, or whatever form of propulsion (unless it has wing's) was designed to take that form of abuse.. :rollside:

[Taylorman]

So is this how it works someone goes against the norm and they're profile is published?? Nice!! send me a P.M and we'll talk......
You sure are coming out the gate swinging with 19 posts.

[SmokinLowriderSS]

So with that being said I suppose your rotating assy. is the lightest you could make it as well??? And as far as getting a boat airborne I dont think any boat, motor, outdrive, pump,v-drive, or whatever form of propulsion (unless it has wing's) was designed to take that form of abuse.. And yes I have been down the liquid 1/4 mile in 7+ secs. 8secs. 9secs and 10 I have also been known to Hang out with the bestHA HA HALmao And I am the Klass Klown not the class bully LOL LOL LOL :) :p :220v: :)
Nope, mine could be lighter. I'm sure somebody makes a lighter flexplate than mine, GM made mine. I have an 80% boat most of the time. She'll run low 70's and I am trying to push her to low 80's, but she's a skiiing/tubing/anchored floating sipping beer workhorse, not a circle-boat nor a drag-boat. I've never deliberately launched her, but it has happened on occasion, once several FEET when I did not see a cruiser-wake while outrunning another jet (my kidney's still remember it like yesterday).
Someday I will be able to get to a SDBA or such race and put her in River Racer, just to do it once. The ones once held locally for about 15 yrs, have been gone the last 3, no local sponsor support. :cry: Congrats on your racing experiences.
What I build for a living are meant to fly, yes, what I enjoy on the lake, is not, but I intentionally try to NOT break it while having a good time which is not always puttering arround the marina.

[Moneypitt]

This thread was about as long and opinuated as the last one on this subject. What fun......Some good point, some bad points and some with no points at all......but everyone has their idea of what works best, what HAS worked best for them and what they will recomend to others as BEST......If we all wanted the same items on or boats/motors there would probably be a shortage, and the costs would be even more than we pay now. Anyway, everyone have a safe and sane New Years, keep the wet side down....MP

[Klass Klown]

So with that being said I suppose your rotating assy. is the lightest you could make it as well??? And as far as getting a boat airborne I dont think any boat, motor, outdrive, pump,v-drive, or whatever form of propulsion (unless it has wing's) was designed to take that form of abuse.. And yes I have been down the liquid 1/4 mile in 7+ secs. 8secs. 9secs and 10 I have also been known to Hang out with the bestHA HA HALmao And I am the Klass Klown not the class bully LOL LOL LOL :) :p :220v: :)
Who is this guy?

[396_WAYS_TO_SPIT]

In a Jet Boat you will destroy a impeller with a heavy Flywheel, because you can not slow the rpms quick enough, 396 has a perfect example of that somewhere. By loading and unloading hard at high rpm, 5500 and above they will crack and break.
Amen!!! Been there and done that! Destroyed 2 impellers due to airing it out.......

[SmokinLowriderSS]

Amen!!! Been there and done that! Destroyed 2 impellers due to airing it out.......
Just quit usin' that cheaper white metal 396. Nice, strong, shiny silver Stainless Steel the way to go. No more breakages. (no more boating either 'cause all the gas $$$ went into the $950 impeller :cry: )

[396_WAYS_TO_SPIT]

Just quit usin' that cheaper white metal 396. Nice, strong, shiny silver Stainless Steel the way to go. No more breakages. (no more boating either 'cause all the gas $$$ went into the $950 impeller :cry: )
Thats the plan up my sleeve :cry: :cry: :cry:

[Taylorman]

Just quit usin' that cheaper white metal 396. Nice, strong, shiny silver Stainless Steel the way to go. No more breakages. (no more boating either 'cause all the gas $$$ went into the $950 impeller :cry: )
How about letting off the gas in the air. Little cheaper in my opinion.

[SmokinLowriderSS]

How about letting off the gas in the air. Little cheaper in my opinion.
That's why I learned to pedal my 454, so as to not blow up my 'luminum. :rollside: :rollside:
The new HP this year and next tho demand steel, the budget demands Mag-Bronze, the budget won. :cry:

[Squirtin Thunder]

That's why I learned to pedal my 454, so as to not blow up my 'luminum. :rollside: :rollside:
The new HP this year and next tho demand steel, the budget demands Mag-Bronze, the budget won. :cry:
How much power do you have ???

[Taylorman]

That's why I learned to pedal my 454, so as to not blow up my 'luminum. :rollside: :rollside:
The new HP this year and next tho demand steel, the budget demands Mag-Bronze, the budget won. :cry:
Ive seen broken bronze impellers also from not pedaling.

[Squirtin Thunder]

I will be running a A3 aluminum all season @ no more than 5500rpms.
You can buy 4.285 Aluminum impellers for the price of one Stainless.

[Taylorman]

I will be running a A3 aluminum all season @ no more than 5500rpms.
You can buy 4.285 Aluminum impellers for the price of one Stainless.
What brand A3?
What is 4.285 aluminum?

[SmokinLowriderSS]

How much power do you have ???
Thius summer, with the thru-transom headers, I should pull 400HP without the Sniper nitrous plate (replaces the 75HP MMM setup from '79), another 100-150HP. Next year's porting on my heads (BBC open chamber '049's) with valve up-size should net me clost to 500 HP total according to the head shop that does DuaneHTP's. The nitrous will then drop to 100 (if not already there) and stay there. Close to 600 HP total by spring '07. My budget won't let me do stuff all at once.

[SmokinLowriderSS]

And I don't plan to forget how to pedal her when necissary.
Hmmmmm Somehow that just doesn't look, or read, quite as "right" as it sounds ......... :D :D :D

[wsuwrhr]

What brand A3?
What is 4.285 aluminum?
I am guessing there are 4.285 aluminum impellers in the cost of 1 stainless impeller.
Brian

[Taylorman]

I am guessing there are 4.285 aluminum impellers in the cost of 1 stainless impeller.
Brian
How do you fit 4.285 impellers in a jet drive?

[sleekcrafter]

How do you fit 4.285 impellers in a jet drive?
Now your talking a multi-stage pump impeller.
[QUOTE=SQUIRTIN THUNDER]You can buy 4.285 Aluminum impellers for the price of one Stainless.
Jim, who want's the head ache, of changing out impellers on their boat, or pulling it apart to check it out. It's like point's ign vs Electronic ign, you want to change points every 10,000 miles or not. Just some perspective, I pitty the people who break because of lack of proper maintance, and go out beating the crap out of things. Aluminum. Bronze, and Stainless all have their places.
Sleek

[MACHINEHEAD]

Once the flywheel sucks the power from your engine, it has to be decellerated to release it. Sounds counter productive in a boat.
Oh yea its a flexplate!

[396_WAYS_TO_SPIT]

How about letting off the gas in the air. Little cheaper in my opinion.
I did that but when you load the pump again is when it tears up parts.....

[Squirtin Thunder]

What brand A3?
What is 4.285 aluminum?
Berkeley
4.285 aluminum impellers for the price of one stainless.

[Squirtin Thunder]

Now your talking a multi-stage pump impeller.
[QUOTE=SQUIRTIN THUNDER]You can buy 4.285 Aluminum impellers for the price of one Stainless.
Jim, who want's the head ache, of changing out impellers on their boat, or pulling it apart to check it out. It's like point's ign vs Electronic ign, you want to change points every 10,000 miles or not. Just some perspective, I pitty the people who break because of lack of proper maintance, and go out beating the crap out of things. Aluminum. Bronze, and Stainless all have their places.
Sleek
I don't have a set back pump it takes about 1.5hrs to change the impeller. But I am very curious to see if the impeller has cav burns or the suction housing or anything else. I also like to check my thrust bearing, being I put tons of use on the boat. Hell I have never went 10K without a tune-up of some sort. I mean When always shooting for optimum performance you have to check and tune. I mean I only have 478K on my stock untouch engine in my truck and it gets better milage today than the day it came off the showroom floor.

[Squirtin Thunder]

Thius summer, with the thru-transom headers, I should pull 400HP without the Sniper nitrous plate (replaces the 75HP MMM setup from '79), another 100-150HP. Next year's porting on my heads (BBC open chamber '049's) with valve up-size should net me clost to 500 HP total according to the head shop that does DuaneHTP's. The nitrous will then drop to 100 (if not already there) and stay there. Close to 600 HP total by spring '07. My budget won't let me do stuff all at once.
I ran 560hp all season with no problems, I will be putting about 700hp to the A3. But the trick is not turning over 6K and keeping the pump loaded.

[CrdStang]

Oh man, this thread has been great..I can't believe so many of you are so lost about the whole flywheel issue. :rolleyes:
Bottom line, unless your boat has a clutch, your flywheel is only hurting you.
(possible ring gear issues notwithstanding)
In a car, the rotational energy stored in the large mass of flywheel is used to help the engine get the car into motion while the clutch is engaging. Once the clutch is locked up, the flywheel is only hurting your car too. :idea:
:argue:

[sleekcrafter]

Jims right, I ran an American Turbine AA impeller for 5 years, with 700HP never had any issues, cracks, or excessive wear, Treat it right and they will last a long time :crossx:
Sleek

[steelcomp]

One more thing, you take the pro stock class in N.H.R.A they run lenco's, Liberty's etc, Do you not think in the most Competitive class in N.H.R.A if rotating weight was such the issue i.e. above they would be running ---oh let's say an automatic HA HA lol Lmao Guess again!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!! I guess boats are more of a science than prostock cars!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! ENOUGH SAID
This made no sense at all! :rolleyes: MP's right, and anyone else that says that rotating mass, AFA acceleration in a boat, is a BAD thing. Simple physics.
Who is this guy?? :notam:

[Glencoe MiniDay]

In A jetboat If you were setup with the right parts say like a Stainless impeller you would not have to worry about swelling the impeller at high r's
Also wouldn't the water in a pump that has an inducer act like the fluid in a converter in a car??

[Squirtin Thunder]

In A jetboat If you were setup with the right parts say like a Stainless impeller you would not have to worry about swelling the impeller at high r's
Also wouldn't the water in a pump that has an inducer act like the fluid in a converter in a car??
Actually that does happen Bottom Feeder has run some test that confirm this, but it is at the bowl.

[steelcomp]

In A jetboat If you were setup with the right parts say like a Stainless impeller you would not have to worry about swelling the impeller at high r's
Also wouldn't the water in a pump that has an inducer act like the fluid in a converter in a car??Actually, a 316 stainless impeller will grow quite a bit at higher R's. In a torque converter, the fluids are contained. Not so in a jet pump, especially on the low pressure side, where the inducer is.

[Duane HTP]

It sounds like Klass Klown doesn't know that most boats do not have a clutch.
KK, there is no clutch in a boat, Therefore no need for all of that flywheel weight. We want these babies to spin up quick. NOT worried about cornering or burn outs. Less weight means quicker acceleration. Besides, the shaft and impeller work as a flywheel anyway.

[steelcomp]

It sounds like Klass Klown doesn't know that most boats do not have a clutch.
KK, there is no clutch in a boat, Therefore no need for all of that flywheel weight. We want these babies to spin up quick. NOT worried about cornering or burn outs. Less weight means quicker acceleration. Besides, the shaft and impeller work as a flywheel anyway.Duane, check out the boat drags...there's plenty of boats with clutches in them. Granted, you don't have to "slip" it like in a car, therefore you're right about not needing the flywheel, but there are boats with clutches, none the less.
Happy New Year! :D

[Duane HTP]

Steelcomp, Please read my post again.
most boats do not have a clutch.

[steelcomp]

Duane:KK, there is no clutch in a boat,
Make up your mind.

[Duane HTP]

Most boats don't have clutches. Especially jet boats and that's what I normally deal with. Second sentence was a mistake, the thread is not about how many have clutches. Rather, should you use a heavy flywheel. I say no.

[MACHINEHEAD]

Next season Im going to run a 292lb. flywheel connected to a large mass of rubber bands and garage door springs, coupled with a flexplate (of course)and a coppernickel impellor :rollside:

[steelcomp]

Most boats don't have clutches. Especially jet boats and that's what I normally deal with. Second sentence was a mistake, the thread is not about how many have clutches. Rather, should you use a heavy flywheel. I say no.I know, Duane, just messin with ya. :p We agree on the flywheel.
Happy New Year!! :D

[phegan]

i just wanted to add, in case it wasn't mentioned. With the heavy flywheel you are adding to the gyroscopic effect. what i mean is it will resist a change in direction, like when you want to turn.those resisting forces could be quite large.Plus, all those forces will have to be transmitted thru the hull to the main bearings and at the speeds you guys run you would want keep that to a minimun. Anyone who has used a electric die grinder will know what i mean.
Happy new year

[Duane HTP]

Happy New Year to you, and everyone else reading these threads.
Duane HTP

[sleekcrafter]

Happy New Year to you, and everyone else reading these threads.
Duane HTP
So who's reading?? I just look at the pictures :D
Happy new year!

[wsuwrhr]

How do you fit 4.285 impellers in a jet drive?
Are you serious?

[SmokinLowriderSS]

Next season Im going to run a 292lb. flywheel connected to a large mass of rubber bands and garage door springs, coupled with a flexplate (of course)and a coppernickel impellor :rollside:
Hey Duane, THAT looks like a hot ticket. I've got a couple spare garage door springs, can you get me a line and price on the copper/nickel alloy impeller? Size "A". I have a bronze and an aluminum I can go in on trade with. Now to e-mail my mail-person friend about big rubber bands for cheap.
:D :D :D

[Taylorman]

Are you serious?
About as serious as the winking dog in your avatar.