Rudder Water Pickup - How to get more water flow?

[LuckY07]

I picked up an OSE-80050 rudder from here and will be installing it (water inlet only on one side) on my Voractiy 36.

502b20-2.JPG

This is what the stock Voracity rudder looks like (it has water inlets on both left and right side)

prb281029.jpg

Since the stock rudder has 2 water inlets, will the upgraded rudder need more flow?

Should I file the new rudder down on the trailing edge to make the single inlet bigger?

[runzwithsizorz]

I picked up an OSE-80050 rudder from here and will be installing it (water inlet only on one side) on my Voractiy 36.

[ATTACH=CONFIG]145531[/ATTACH]

This is what the stock Voracity rudder looks like (it has water inlets on both left and right side)

[ATTACH=CONFIG]145532[/ATTACH]

Since the stock rudder has 2 water inlets, will the upgraded rudder need more flow?

Should I file the new rudder down on the trailing edge to make the single inlet bigger?

I would not, my method works best. Buy a drumel tool set, and add the drill bits as well, it's great item to have around!.
Also, how on earth are you getting such long run times? Do you have a battery/cell checker? if not GET ONE!
Take everything you hear about water cooling with a grain of salt. There is a HUGE thread on this, and apparently the jury is still out. IMHO, more, and colder is better.
And speaking of more, once things start to heat up, they're really not going to cool down with you doing half throttle or less. Decide what kind of run you want to do and stick to it. In short, try to be smooth.
Your temps are pretty darn good, almost unbelievable. Until you start modding, or propping up, let sleeping dogs lay. Did you move the jacket tube from top to bottom? and do you know why?

[LuckY07]

I would not, my method works best. Buy a drumel tool set, and add the drill bits as well, it's great item to have around!.
Also, how on earth are you getting such long run times? Do you have a battery/cell checker? if not GET ONE!
Take everything you hear about water cooling with a grain of salt. There is a HUGE thread on this, and apparently the jury is still out. IMHO, more, and colder is better.
And speaking of more, once things start to heat up, they're really not going to cool down with you doing half throttle or less. Decide what kind of run you want to do and stick to it. In short, try to be smooth.
Your temps are pretty darn good, almost unbelievable. Until you start modding, or propping up, let sleeping dogs lay. Did you move the jacket tube from top to bottom? and do you know why?

Not sure how I got such a long run time with cool temps. The only thing I can thing of is I was taking it easy with the boat and going 30-50% throttle
most of the time and the water was like glass.

After I was done with my run I checked my batteries with my multi-meter and they were ~11.1v each. I then charged them to 11.4v for storage.

I did notice on my startups (from no throttle) that there was a bit of gurgling noise until I got the boat up to speed. Is that normal? Sign of running wet?

The boat had just a couple drops of water in it after my run, I did tape the hatch but was also using reverse where it kicks the water back to the canopy.

As for the jacket tubes, I haven't touched anything.. it's exactly how it came from the factory. How/why do you move the jacket tube from the top to bottom?

Is the method you're suggesting for my rudder to add a second water pickup on the rudder? Or just make the existing hole bigger?

[Tamelesstgr]

Here is a chart I like to use for battery reference, you want to have about 20% capacity left in the packs to keep them performing the best for the longest amount of time (pack health long term)

Battery Voltages.JPG

The gurgling is the propeller starting to spin up under the water, it's common. People refer to it as Cavitation "the formation of bubbles in a liquid, typically by the movement of a propeller through it." Too small propeller for your specific setup will have lots of cavitation and the boat will struggle to get up on plane. On the flip side, too large of a propeller and the prop "grabs" the water and you can actually flip the boat when hitting the throttle too fast.

"Running Wet" refers to the hull attitude, when the bow of the boat is plowing water that is running wet. You want the back ride pad or sponsons skimming ontop of the water without affecting your ability to drive or handle waves etc.

[Tamelesstgr]

This section is worth a browse as well:

http://www.offshoreelectrics.com/info.php

[LuckY07]

This section is worth a browse as well:

http://www.offshoreelectrics.com/info.php

Thanks for the link! I didn't see this and I'm going to read it all.

[LuckY07]

Here is a chart I like to use for battery reference, you want to have about 20% capacity left in the packs to keep them performing the best for the longest amount of time (pack health long term)

[ATTACH=CONFIG]145533[/ATTACH]

The gurgling is the propeller starting to spin up under the water, it's common. People refer to it as Cavitation "the formation of bubbles in a liquid, typically by the movement of a propeller through it." Too small propeller for your specific setup will have lots of cavitation and the boat will struggle to get up on plane. On the flip side, too large of a propeller and the prop "grabs" the water and you can actually flip the boat when hitting the throttle too fast.

"Running Wet" refers to the hull attitude, when the bow of the boat is plowing water that is running wet. You want the back ride pad or sponsons skimming ontop of the water without affecting your ability to drive or handle waves etc.

Great info! That chart will be saved and I will use that for reference.

I always figured you just run the boat until the LVC kicks in, but maybe I was wrong.
I don't think my LVC kicked in (or I didn't notice it) before I brought my boat in from the first run ever.

Is it bad to run the batteries until the LVC kicks in, assuming I will set it to storage charge (11.4v) afterwards?

The confusing part is my manual says the default LVC is 3.2v/cell. So that wouldn't even kick in until the 3s battery was down to 9.6v..

the highest you can set the LVC to is 3.4v/cell on this ESC which would still be under 11v.

[Tamelesstgr]

I personally don't trust the LVC, it's best to know by trial and error how long you can run till your packs are down 20 about 3.75-3.80 volts. That's based on running full throttle the whole time. For example, my Shockwave is a 3 minute boat, I don't run any longer than that, sometimes the packs will have a little more juice in them, but I'd rather be safe. If your batteries run down too low bad things can happen. LIPOS will "puff" from the breakdown of the chemicals inside the cells. Read up on proper charging and storage as well. I personally always balance charge and only charge based on the recommended "C" rating

[LuckY07]

I personally don't trust the LVC, it's best to know by trial and error how long you can run till your packs are down 20 about 3.75-3.80 volts. That's based on running full throttle the whole time. For example, my Shockwave is a 3 minute boat, I don't run any longer than that, sometimes the packs will have a little more juice in them, but I'd rather be safe. If your batteries run down too low bad things can happen. LIPOS will "puff" from the breakdown of the chemicals inside the cells. Read up on proper charging and storage as well. I personally always balance charge and only charge based on the recommended "C" rating

I'm going to try and charge/discharge the batteries after every usage by using the "storage mode" feature on my charger (sets it to 11.4v).

One thing I was wondering after reading up on battery storage is whether or not they can/should be put in the fridge to keep cool. My house is generally humid and warm in the summer so the only options to keep them cool are in the basement or fridge. The basement has the furnace, so that doesn't seem like the best place.. what are your thoughts on storing LiPo's?

[Tamelesstgr]

I store my lipos in the little silver charging sacks inside a metal toolbox that has some vents in it. You don't want a completely sealed container if something does happen to go wrong you want the smoke and pressure to escape. I keep everything in my basement which is cool enough I think. It's also important to note, don't leave lipos in direct sunlight or in a hot car during the summer.

[jwohlt]

I have to side with Jay....test have shown just having a small flow is just as good. Somehow people think they need some high pressure water and it cools better...not the case. If anything you increase pressure and you might create leaking at your cooling can or worse...blowing a hose off...which I use plastic ties on all nipples anyway. I do like rudders with both side pickups.

[LuckY07]

I have to side with Jay....test have shown just having a small flow is just as good. Somehow people think they need some high pressure water and it cools better...not the case. If anything you increase pressure and you might create leaking at your cooling can or worse...blowing a hose off...which I use plastic ties on all nipples anyway. I do like rudders with both side pickups.

The reason I wanted to upgrade my rudder was because of the breakaway feature. I don't want to rip the transom if I hit something.

Can't I just use a brass bolt as the bottom bolt in my stock rudder to achieve the same "breakaway" as this new OSE rudder?

I like how the stock Voracity rudder has 2 inlets vs this aftermarket one.. but I am worried if I hit something.

[pistol18]

The reason I wanted to upgrade my rudder was because of the breakaway feature. I don't want to rip the transom if I hit something.

Can't I just use a brass bolt as the bottom bolt in my stock rudder to achieve the same "breakaway" as this new OSE rudder?

Yes you can use a brass or plastic bolt to save your transom and it is simple insurance.

Also, regarding dual water cooling lines, the veterans have shared their knowledge above and my simple analogy is this. I have both a motley crew and lucas oil cats(same boat, all stock, motor/escs)
MC has dual cooling lines, 1 to motor, 1 to esc
LO has stock single line to both esc/motor.

Both run @40-42 mph on 4s and both have motor/esc temps within 2-3* after a 4 minute run. So my scientific deduction is that single line cooling works fine for stock boats.

[Tamelesstgr]

That's really interesting on the two different cooling setups, thanks for sharing. I guess I should rethink my builds going forward, made sense to me initially

[Jeff Wohlt]

Yes....just plastic bolt and nut are good. My ace hardware carries that stuff.