Loader question

« **on:** August 28, 2015, 12:53:01 PM »

Got a hold of a different style loader and was wondering if this would benefit my boat or not?

Pro and cons?

18ft Bahner 454 12jg approx 450 hp boat does mid 70s.

Sent from my iPhone using SoCalJetBoats

« **Reply #1 on:** August 28, 2015, 01:28:46 PM »

Current set up spins an A to 5000rpm no Diverter or droop.

Sent from my iPhone using SoCalJetBoats

« **Reply #2 on:** August 28, 2015, 01:39:47 PM »

It will load your pump better and most likely drop rpm with that loader

Sent from McIntyre park

« **Reply #3 on:** August 28, 2015, 01:53:40 PM »

What kind of boat and what power? One test is worth a thousand theories. Let us know what you find.

« **Reply #4 on:** August 28, 2015, 02:04:30 PM »

Quote from: jyeager on August 28, 2015, 01:39:47 PM

It will load your pump better and most likely drop rpm with that loader

Sent from McIntyre park

So dropping RPM id most likely loose MPH correct??

« **Reply #5 on:** August 28, 2015, 02:10:25 PM »

Quote from: Flusher on August 28, 2015, 01:53:40 PM

What kind of boat and what power? One test is worth a thousand theories. Let us know what you find.

Its a fairly light layup 82 18ft Bahner Bubbledeck. Mild 454 bored to 461, oval port heads, smaller cam, Victor Jr with a 750 DP, MSD HEI, OT Bassets. Approx 450 HP Spins an A impeller about 5000rpm. Mid 70s

« **Reply #6 on:** August 28, 2015, 02:50:45 PM »

The long loader might make it feel "stuck to the water" if the ramps hang down too far. But since you don't have a shoe, a more aggressive loader might help load the pump harder. Unless you are currently unloading the pump, I don't think you would see a difference in RPM.

« **Reply #7 on:** August 28, 2015, 03:00:48 PM »

Quote from: Flusher on August 28, 2015, 02:50:45 PM

The long loader might make it feel "stuck to the water" if the ramps hang down too far. But since you don't have a shoe, a more aggressive loader might help load the pump harder. Unless you are currently unloading the pump, I don't think you would see a difference in RPM.

My southwind 18 lost 200 RPM with that exact loader. B impeller no shoe or rideplate and 550hp.

Sent from McIntyre park

« **Reply #8 on:** August 28, 2015, 03:11:32 PM »

Quote from: jyeager on August 28, 2015, 03:00:48 PM

My southwind 18 lost 200 RPM with that exact loader. B impeller no shoe or rideplate and 550hp.

Compared to?

« **Reply #9 on:** August 28, 2015, 03:44:44 PM »

Quote from: Flusher on August 28, 2015, 03:11:32 PM

Compared to?

My old boat had a Very similar set up to his.

Sent from McIntyre park

« **Reply #10 on:** August 28, 2015, 07:06:49 PM »

Jake, did you have a loader in it before going to the ramp style loader?

« **Reply #11 on:** August 28, 2015, 07:29:00 PM »

Quote from: crewchief22 on August 28, 2015, 07:06:49 PM

Jake, did you have a loader in it before going to the ramp style loader?

Me? Or other Jake?

I looked on the Berkeley site and the one I have in now looks like the "SE" sport edition loader, and this new one looks like the SS loader.

I just wanna know if it'll hurt performance or not. Guess I should just try it then...

Sent from my iPhone using SoCalJetBoats

« **Reply #12 on:** August 28, 2015, 07:29:02 PM »

Quote from: JBASHAM on August 28, 2015, 02:04:30 PM

So dropping RPM id most likely loose MPH correct??

This comment is incorrect.

On a jet boat, RPM has little to do with hull speed.

The determining factors are, in no specific order;

Hull weight, center of gravity, nozzle volume and velocity, drag coefficient.

RPM only indicates the relationship between the horsepower and the pumps ability to absorb it.

GT

« **Reply #13 on:** August 28, 2015, 08:17:27 PM »

Quote from: GT Jets on August 28, 2015, 07:29:02 PM

This comment is incorrect.

On a jet boat, RPM has little to do with hull speed.

The determining factors are, in no specific order;

Hull weight, center of gravity, nozzle volume and velocity, drag coefficient.

RPM only indicates the relationship between the horsepower and the pumps ability to absorb it.

GT

So if the pump is being loaded harder wouldn't it take more horsepower to sustain the same rpm? Therefore losing mph?

Sent from my iPhone using SoCalJetBoats

« **Reply #14 on:** August 28, 2015, 08:39:16 PM »

Quote from: JBASHAM on August 28, 2015, 08:17:27 PM

So if the pump is being loaded harder wouldn't it take more horsepower to sustain the same rpm? Therefore losing mph?

Sent from my iPhone using SoCalJetBoats

You're looking at it funny.

So lets say I can force some water into the pump with a very small increase in the drag effect.
Let's say that extra water provides the inlet of the impeller with a 30 psi NPSH (might want to look that up "Net Positive Suction Head" I'm a major nerd when it comes to this stuff.) That net pressure gain is a "freebie" and is work the impeller does not have to do. Now spin the impeller through it gaining a delta pressure of over 120psi..... That 150psi outlet pressure will be really valuable at the nozzle.

The reason the engine will be dogged down is because of the lack of cavitation, which "robs" the impeller of performance, or the ability to absorb power. Which can equate to added thrust. Ultimately that is the goal. Correct?

GT

« **Reply #15 on:** August 28, 2015, 08:48:48 PM »

Correct?! You tell me! Lol! You know way more about this than I do.

I just want some opinions if this loader would be worth installing or not.

Sent from my iPhone using SoCalJetBoats

« **Reply #16 on:** August 28, 2015, 08:49:02 PM »

The impeller should be the determining factor for RPM. Anything that deprives the pump of water will cause RPM to increase. Our current philosophy is to load the pump as hard as possible and cut the impeller to match the engine power curve.

Bowl pressure is directly influenced by suction pressure. Say your pump has the ability to step up the pressure 250 PSI. If you are loading your pump as hard as possible and you're developing 50 PSI on the suction side, bowl pressure will be 300 PSI. If you are only producing 10 PSI on the suction side, bowl pressure will only be 260 PSI.

« **Reply #17 on:** August 28, 2015, 08:54:18 PM »

Quote from: Flusher on August 28, 2015, 08:49:02 PM

The impeller should be the determining factor for RPM. Anything that deprives the pump of water will cause RPM to increase. Our current philosophy is to load the pump as hard as possible and cut the impeller to match the engine power curve.

Bowl pressure is directly influenced by suction pressure. Say your pump has the ability to step up the pressure 250 PSI. If you are loading your pump as hard as possible and you're developing 50 PSI on the suction side, bowl pressure will be 300 PSI. If you are only producing 10 PSI on the suction side, bowl pressure will only be 260 PSI.

Isn't that what I just said? Hahaha

Yes, if installed properly and not set too deep, that loader is worth trying.

What do you have in it now?

GT

« **Reply #18 on:** August 28, 2015, 08:56:04 PM »

Ok. I re-read your response.

So this loader should build more bowl pressure at a lower rpm because there will be less cavitation...correct?? More bowl pressure equals more mph regardless of the engine rpm?

Sent from my iPhone using SoCalJetBoats

« **Reply #19 on:** August 28, 2015, 08:57:55 PM »

Quote from: GT Jets on August 28, 2015, 08:54:18 PM

Isn't that what I just said? Hahaha

GT

To much multi-tasking makes me slow of the line

« **Reply #20 on:** August 28, 2015, 09:05:08 PM »

Quote from: JBASHAM on August 28, 2015, 08:56:04 PM

Ok. I re-read your response.

So this loader should build more bowl pressure at a lower rpm because there will be less cavitation...correct?? More bowl pressure equals more mph regardless of the engine rpm?

Sent from my iPhone using SoCalJetBoats

Theoretically yes. You're looking at it funny though.

It's difficult to use an absolute as far as the cavitation statement.

So lets just say if there is cavitation present, for sure. Providing the drag effect is kept in check.

GT

« **Reply #21 on:** August 28, 2015, 09:07:20 PM »

Quote from: Flusher on August 28, 2015, 08:57:55 PM

To much multi-tasking makes me slow of the line

You taking a dump or clipping your toenails?

Lmao... I unfortunately know what your talking about.

GT

« **Reply #22 on:** August 28, 2015, 09:11:20 PM »

Hahaha thanks a lot guys! I'll give it a try and report my findings.

GT, the loader in it now is a "SE" sport edition style loader.

Sent from my iPhone using SoCalJetBoats

« **Reply #23 on:** August 28, 2015, 09:12:25 PM »

Quote from: GT Jets on August 28, 2015, 09:07:20 PM

I unfortunately know what your talking about.

GT

Indeed you do!

Arguing with the wife while trying to buy bolts to mock up a fuel tank.

I much rather be talking about loaders on SCJB. I just need a job that will pay me to do that.

Cheers,

Joe

« **Reply #24 on:** August 28, 2015, 09:13:45 PM »

Quote from: JBASHAM on August 28, 2015, 09:11:20 PM

Hahaha thanks a lot guys! I'll give it a try and report my findings.

GT, the loader in it now is a "SE" sport edition style loader.

Sent from my iPhone using SoCalJetBoats

I think the Ass-O-Nom-Meter will be able to differentiate a performamce gain. It won't be huge, but betting you can tell.

GT