Newbie ESC Water Cooling Question

[VedderHunter]

Finally got my PB Impulse 31 up and running. First off....I love this boat. Sold my old nitro AC Wave Slave and bought this boat. Excellent choice in my mind. But I have a question regarding the water flow through the ESC. Did not see much water coming out the port on the side when running so I was concerned there might be a blockaged. Felt temperature of batteries (2x 2S 40C Turnigy 5000mah) and stock ESC, and both were just warm after 7mins of giving it hell. Though I am still worried about the water flow issue. So I disconnected the tube off the rudder and found it very hard to blow through. So I slowly checked piece by piece starting with the motor cooling jacket. Air went through fine. When I got to the ESC, I could barely get any air through. Is this normal? Is there a better way to check this or am I just being paranoid?

All stock setup. Any advice would be appreciated.

[CeilidhKeith]

How i check water lines is with a squeezy bottle of water pumping water through the pipe that you take off the rudder then watch for water squirting out of the outlet on the side of the boat.

[FRED]

Now from what i read posted, blow thru the rudder top and check the flow. I would increase the size of hose as i,ve seen dark blue hose which seems to collaspe while some hoses are thicker and more uniform. Also the rudder water-pickup has holes and you could gently ream and sand smooth afterwards. These are suggestion. Reply back on what you've found. NICE POST_ NICE BOAT>









also

[BHChieftain]

I use probat 60A ESCs in a couple of boats and I can blow air thru those without a problem. You want to see a steady stream of water exiting the boat when you run (does *not* need to be a firehose, but not a dribble...). But note, your definition of "hard to blow through" may not equal mine...
Take a mouthful of water and blow it thru the rudder tube and see if you can get a light stream of water to exit.

Like Fred said, the rudder is frequently a problem spot-- if you have problems in the future check there first as they can get clogged.


Chief

[backbayboy]

I've had sporadic problems with Proboat ESC's. I'd suggest buying the compressed air from any CVS,Riteaid,Radio Shack, what is used to blow off computer keyboards and electronic parts, it comes with a small tube which you can fit into the imput of the ESC, Remove the input tube and place the tube from the can directly into the imput of the ESC, you should get a very strong flow of air, you might blow out some dirt which will block the water flow. Dirt tends to get stuck in the Proboat ESC and this is a good practice. This should work for you. You can also buy a plastic water pickup and silicone it to the transom if you don't want to drill another hole and run this. I've found this forces a much higher water pressure than the rudder pick up. You can get the plastic pick ups at TH or get the metal ones here at OSE, I've silicone the pickup to my SV27 and my Widowmaker with no problems and have greatly increased the efficiency of the waterflow. good luck

[madmorgan]

at walmart in the rv sectin i found a little piece you can screw into the end of your outside water hose and it has a nipple in it for like 3 bucks its called a blow off plug or something i attach water lines to it and turn the water on. i dont think the pressure from them little cans of keyboard spray is enough. or if you have access to a air compressor you can find a barbed fitting that screws into a blow gun and really push some air through . i would knock down pressure to about 25 or so though as it would be about 90 psi coming out. also i use the yellow or blue large fuel line for water lines.

[FRED]

I think the answer is to discontinue using the rudder pickup. I mentioned this in my post............. I'd use use and make it 5/16" size and taper it at the bottom to catch water. This time of year we have crap that is bigger than rudder pickup. Now by the tine a boater realizes that no water is coming out. Trouble could already be brewing. This can happen and might save a headache. Now you could go the PROP WASH route.

[Derrick Davis]

Here is another suggestion / thought -
I have found that there is a strong possibility that the "blockage" is actually due to how the ESC was assembled. They may have added a bit too much silicone when they screwed the metal nipples into the ESC. If you have checked the rest of the cooling system - tubing, rudder, motor cooling jacket...then there is a good chance that there is dryed silicone obstructing the flow from inside one (or both) of the metal nipples that is connected to the outside of the ESC where the tubbing connects. You can simply unscrew the nipple(s) and make sure you don't see silicone hanging down in front of the hole. Once checked (and cleaned, if needed) you can simply add a dab of new silicone to the nipple before you screw it back in. It's a snap!
I encountered this with a replacement Proboat 60 AMP ESC. Works like a charm now with very good water flow. My 3/4 cents...for whatever it's worth. :tiphat:
Ciao,

D

[JIM MARCUM]

Another look at your options. Pull the H2O hoses off the rudder & blow thru them. If it flows well it should be OK. Lots of variables here, so the first thing you need is an IR temp gun. Use it to check Motor, LIPOs & the ESC temps after a few full speed passes. If the motor & ESC are below 130-140 F you're OK. The lower the better.

You won't get that much water flow from the discharge ports at low-medium speeds. Do a high speed pass or two for a visual check.

Enlarging the rudder intake holes won't have a negative impact on water flow, but it will create a tiny bit more drag. Over all - no big deal.

You can quickly check flow thru an ESC or motor water jacket by blowing thru a short (6-12") piece of water tubing. I have found blockage in an ESC that way. Blockage was caused by a combo of left over metal shavings from the threading process & excess sealant. Removed the water nipple, used a hand drill & bit the same size as the nipple hole to clear it out, and blew out the crud with an air hose. After that it worked great.

Hopes this helps. JIM

[properchopper]

All of that blowing and flow checking is not an accurate way of diagnosing the problem unless it exactly duplicates the flow rate and pressure of the rudder pickup. The two likely suspects, as have been mentioned are excessive sealant on the motor barbs and assembly sealant blocking the speedy. Solution is to ream and clean. Not mentioned but often the culprit is the motor barbs being screwed in too far and contacting the motor can, blocking flow. By unscrewing and carefully notching the threaded motor end of the barbs this won't restrict flow if the barb gets screwed in too far.:thumbup1:

[madmorgan]

i actually worked on a forklift that was over heating one time that had a freshly built engine , the rebuilder went in access of silicone ont the water pump instead of buying new gaskets. let me tell ya the cooling line was near plugged up cuz they started the motor and the water pulled the squished uncured silicone into the line. same concept though i figured i would give a idea on new builds to precheck for water leaks.

[JIM MARCUM]

Tony, so blowing sucks?:confused1: JIM

[m4a1usr]

Felt temperature of batteries (2x 2S 40C Turnigy 5000mah) and stock ESC, and both were just warm after 7mins of giving it hell. Though I am still worried about the water flow issue. Any advice would be appreciated.

After seven minutes of run time your worried about heat? Trust me when I say if your getting seven minutes on a stock setup, and more importantly, your happy with the performance, heat issues come into worry or concern? Your good. Oh you can make it cool better. Or should say it can be more efficient. But whats the point?

I'm not being sarcastic so please dont misinterprit my comments. Its just that what you describe is not anything to truely be concerned about. Good run time. Low thermal impact to operating components. Boat not performing below your expectations. Sounds not all that bad to me. Just my 2 cents.

John

[JoeOvercoat]

When you suggest "a high speed pass or two for a visual check", how much water should be seen in this boat/typical boat?

And/or do you have a guess at how much water should spout out of the rudder with the hose disconnected...how tall that should be?

(Question moved to http://forums.offshoreelectrics.com/showthread.php?35008-How-Much-Water-Pressure-Should-A-Typical-Rudder-Pickup-Generate&p=427231#post427231 )

[JonD]

Enlarging the rudder intake holes won't have a negative impact on water flow, but it will create a tiny bit more drag. JIM

Hi Jim,

When I increased the size of the rudder intake holes on my Genesis I started shearing the nylon safety screws with ease, and even with the brass screws that I am using now, they are getting quite deformed after about four x 15min runs. I am putting this down to the extra drag on the rudder due to the larger inlet holes - they are quite a lot larger. I can now see a very decent show of water squirting out the outlet on the side of the hull, even at moderate speeds (guessing about 20% of it's 60mph top speed). Now thinking I may have gone a bit far in increasing the size of the inlet holes.

I am going to be offsetting the rudder, and thinking about doing things a bit different. I certainly like the extra water flow that the increased size inlet holes give me, but when I offset the rudder this extra drag is going to make the boat veer more to one side. So I am thinking about filling in the rudder inlet holes and putting a hull mounted water inlet pick up on the other side to componsate for the normal rudder drag. Does this make sense?

One concern I have about a hull mounted water pick up on the Genesis, either under the bottom of the boat, or mounted on the transom, is will it pick up a consistent and reliable flow of water especially at high speed if the boat is barely skimming (flying) across the top of the water ? At least with a rudder pick up you can guarantee it is always under water.

Just thinking, on the Genesis the transom is mounted higher and fully out of the water. Maybe the pick up needs to be attached to the back of the sponson. Didn't you do a conversion from rudder inlet to separate twin water pick up on a Genesis? I seem to remember a posting from you a few months ago on this.

Jon

[JIM MARCUM]

Hi Jim,

When I increased the size of the rudder intake holes on my Genesis I started shearing the nylon safety screws with ease, and even with the brass screws that I am using now, they are getting quite deformed after about four x 15min runs. I am putting this down to the extra drag on the rudder due to the larger inlet holes - they are quite a lot larger. I can now see a very decent show of water squirting out the outlet on the side of the hull, even at moderate speeds (guessing about 20% of it's 60mph top speed). Now thinking I may have gone a bit far in increasing the size of the inlet holes.

I am going to be offsetting the rudder, and thinking about doing things a bit different. I certainly like the extra water flow that the increased size inlet holes give me, but when I offset the rudder this extra drag is going to make the boat veer more to one side. So I am thinking about filling in the rudder inlet holes and putting a hull mounted water inlet pick up on the other side to componsate for the normal rudder drag. Does this make sense?

One concern I have about a hull mounted water pick up on the Genesis, either under the bottom of the boat, or mounted on the transom, is will it pick up a consistent and reliable flow of water especially at high speed if the boat is barely skimming (flying) across the top of the water ? At least with a rudder pick up you can guarantee it is always under water.

Just thinking, on the Genesis the transom is mounted higher and fully out of the water. Maybe the pick up needs to be attached to the back of the sponson. Didn't you do a conversion from rudder inlet to separate twin water pick up on a Genesis? I seem to remember a posting from you a few months ago on this.

Jon

Jon, I'd use the H2O inlet(s) that come with your new offset rudder. If you need more cooling, just epoxy a 1/2" aluminum "L" on the sponsons, drill a hole in them to insert the brass tubing pickups, pass the brass thru the sponsons, and hookup silicone tubing to your ESC/motor. The brass pickups ends should be about 1/4" below the sponsons to assure adequate H2O flow at speed. JIM:spy:

[VedderHunter]

Thank you guys for all the great ideas. I have pretty much isolated the issue to the ESC. I tried the mouthful of water idea and found that water flowed freely from the rudder to the ESC input nipple and also from the ESC exit tube to the hole on the side of the boat. As mentioned above, there is a good possibility there is some excess sealant inside of the inlet or outlet of the ESC. I will try to remove the nipples tonight and see if any visable sealant can be found and removed.

On a side note, I did have the boat out last weekend for one run with a new balanced and sharpened X442 Octura Prop. Wow did that make a difference in speed over the stock prop. Only ran 2 min run as I did not want to over heat the motor or batteries.