When cooling your electric R/C motor with a cooling system there are a few things to remember.
Rules of thumb:
- boats running on 12 cells or above must have cooling keeping the motor in top condition and maximise efficiency.
- boats running more than 16 cells needs form of thermostat (read below)
- depending on motor size will vary the size of the mouth on the water pickup
- generally 3mm - up to 700 size
- 4mm - 820 can size an above
- engine mount breather holes recommended over 14 cell use
- brush cooling is also recommended for boats using 16 cells or more
Following these simple rules will help you keep your investment form costing you a new motor.
Motor water cooling
Using over 12 cells and requires cooling to keep your motor in top condition, keep temps down and to maximise the working efficiency of your powerboat. Water is pulled from the lake you are driving in by adding a water pick up to either your hull, trim tabs or built into your rudder. Via silicone hose the water is passed into your boat and through to your motor cooling coil. The cooling coil is made out of 3/16 aluminium tube and acts as a heat sink when placed around the motor, when the water passes through the coil the motor is cooled down. From the coil the water flows via silicone hose to a water exit, back into the lake!
Making a thermostat
Before we go into creating a thermostat you must understand exactly what it is. Thermostats regulate the flow of water passing through something either for efficiency (like on your car in the driveway). Without going in to deep, this system on our model boats is far less complicated than the thermostat systems you see used on all cars. You see, it is one thing to install a cooling system in your monster 14 - 16 cell boat, but if the water passes through the whole system in a blink of an eye, (at top speed) then there will be little time for the water to do its job properly.
So what we need to do is decrease the amount of water passing through the cooling coil by decreasing the diameter in the cooling tube. We do this by putting a zip tie around the silicone tubing connected between the water exit and the cooling coil. Be careful not to apply the zip tie too tight other wise it will be restricted far to much or even completely cut off, which we do not want to see. Simply tighten the zip tie around the silicone tubing to slightly restrict the flow of water passing through so it sits in the coil a little longer and cools your powerplant down to a more manageable level.
Engine Mount Breathers
Where your motor bolts onto your engine mount, be sure to grind out the venting holes to the same shape to that of those the can of the motor its self to maximise airflow in cooling. This can be done by either a dremel or drilling a start hole and a finish hole and using a rat tail file to take out the rest in between. If you don't want to go to all the trouble MPS already have 2 different types of engine mount with breathers already cut out.
Where the terminals are on the rear of the motor brass tubes are soldered to the inside of each of the terminals (nearest to shaft.) Cooling line is then extended to flow through one side then through to the other, then exiting the boat via the existing water outlet.