bentwings

I though this might be a good place to pose this question since you guys deal with water cooling all the time.. I fly warbirds and not flying boats. haha Anyway a big P-51 (96 in span) has a tough time cooling a G-62. It requires quite a large hole in the bottom of the cowl which is far from scale and looks like crap. I also have scale functioning exhaust so it gets pretty hot under the hood.

Do you guys think it would be possible to machine the motor fins down to round, cut circulation slots so water could flow around the smaller fins, then machine a sleeve that would be the outer shell of the cooling jacket. I think it would be sealable with 1/16 section o-rings. With todays epoxies I think I could fabricate a radiator to fit in the scoop of the plane. They actually have a large exit door on the rear of the scoop so it would be closer to scale. A smoke pump would handle circulation I think. I realize there is a weight penalty but I've got at least 4 pounds I could add to the gross weight and not really change the flight capability much. I also have a 5.8 motor that would even be better if I could convert it to water cooling.

I also have my own TIG welder and am skilled in small weldments in aluminum, steel, and stainless so welding is not a problem. I've even considered the possibility of welding the cooling sleeve to the cylinder. I do have machine shop capability available too ....not cheap however.

What do you guys think.???

firelite_marine

I see where your coming from but still wrong forum bud. also I think you may have answered your own question.

mopartybob

bottom line........unadvisable...........w/o the cooling fins should you spring a leak [:@] or pump malfunctions,your cooked....and dead stick, try diffusing/circulating more air into the cowl with diverters that reroute air thru-out the cowl...been there,done that on my 1/5 p-51

BB Modss

I have to agree, at one time i had a 150 twin that we cut for water cooling, used some pre made 120mm rads from aqua computer in Germany, and had a mag drive pump on it, the issue we had was the exhaust overheating, so we made some water blocks for the exhaust, in the end the extra weight really took away from the planes ability to fly correctly, we ended up with 2lb's worth of weight at the trailing edge of the wings to fix the cg, by then i was running out of power to push the plane along.. Im with Bob, try some shrouds or good ducting first.

c-cat

How about a belt driven fan? Maybe some high temp ducting around cooling fins and exaust?

cyclops2

You are going to do something.
How is this, there is a scale radiator under the wing. You only need to dump some of the engine heat there. Water cooled head. small water pump, Tygon tubing. Radiator is 1/4" Aluminium thin wall from Special Shapes,run it front to rear several times in the belly radiator.

You are only dumping the EXCESS heat the nose can not handle. Less than a pound of weight. With a battery.

PM me & we will work it out. Very doable with your skills. Macmasters will supply what we need.

Rich

Justaddwata

My Feedback: (3)

No harm in asking a plane question in the boat forum - I have asked boat questions in the plane forum It is good to go where the experience is.

I have a pair of water cooled G62's. The generate a lot of heat I will agree. Probably the bigger consideration I would be thinking about is the added weight. I know there are some smaller aluminum radiators out there these days (check out some of the liquid cooled computers for ideas) but think the size would need to be pretty large (a few pounds) which would equate to some weight. Add to that a potential need to regulate that heat (thermostat of some kind). True a plane motor is not going to be working as hard as a boat motor so you would not need as much cooling capability as a boat but I am just curious how practical it will end up for you. I guess there is one way to find out

Let me know if you would like pictures of the cooling modifications done to my motors.

cyclops2

Since combustion engines rarely exceed 28 % efficiency It means that a lot, about 70 %, is going out the exhaust as heat & noise. SOO. How about we check up on cooling with a custom Aluminium muffler copied from a Brisson for volume of the noise chamber. Many shapes to make it. Could simply be a double walled exhaust pipe runing around the space in the cowl. Cooling the exhaust would do 2 major things.

Remove heat from the engine compartment.
A cooled exhaust is a VERY quiet exhaust.
Easy enough to make a double walled exhaust with water in it and a car windshield washer pump for circulation. Make the muffler hose nipples same as the pump size. If you put sand between the double walls & in the inner opening, you can bend tight curves.
I think we are getting there. I have used 3/8 copper tubing with VERY tight 180 degree U couplings. Plumbing store. We could use Copper for the muffler. Smaller size, faster heat removal.
Maybe a Brisson straight down with a Cooling box fabricated around the muffler. There are probably 3 or 4 ways to drop the temperature in the cowl. We think, you fabricate. Doable.

BB Modss

Washer pumps were not made to run at 100% duty cycle, they do burn up! magdrive is the only way to go, dangerden sells a 12v dc mag drive thats thin and light. A few of my comp's are water cooled, 2 are under phase change, and my main benching rig runs LN2 for cooling (this is a total loss system) its whats needed for 6.5+ghz benchmark runs.


hmm...Ln2 the motor?? lol

cyclops2

Good news. The duty cycle of a overpowered plane is low. All my washer motors lasted a long time. The disc thermostat which I have several types of, will cycle the pump only when needed.
That is the whole cooling system electrically. Thermostat & a water pump.

Rich

Edit : My 8' PTB was first powered by a 66 CC chainsaw engine with a thermostat and 2 Chrysler windshield washers. Did fine. Except it could not plane at 80# of waterline weight.
A 41# thrust trolling motor in the hull runs it easier with no cooling problems.

Rich

sheograth

BB modss, that picture brings back hilarious memories. Before I got into RC I was building cascades and such

BB Modss

Yes I to was building cascades, whats your name bud?