Smoke systems are a real pleasure to the eye and to the realism of the plane,especially aerobatic aircraft. The system I am talking about is installed on my Midwest Cap 232 with US 41 and a B&B Smoke muffler. The Club President(Gerry Raworth)runs a converted 35cc chainsaw engine with a B&B smoke muffler also. The smoke that his Extra 300S puts out is tramendous and even better on a calm day with no wind.
Once you have all your equipment it's time to start installation. The first thing to do would be to see if your plane has room for all the equipment. The smoke pump should be mounted as close to engine as possible for best pump performance.If pump is too far away it will not work because the pressure line expands too much therefore the pump won't get enough pressure. Try to keep the pressure line no more than 12 inches (not quite sure what the actual length should be but use this as a rule of thumb)
Check to see if your engine has
been tapped for cranckase pressure. If it's already tapped your all set. If it's
not you'll have to take the cranckase apart and examine it for the best spot to
drill a hole.Make sure your fitting will not interfere with the crank shaft or rod. Make sure there is sufficent metal for the threads to grab or else
the fitting will not stay in.Some engines, such as the US Engines 35/41's, or Quad 35/42's
have a small cylinder afair on the side of the lower half of the crackcase that is
designed for crankcase pressure. If you got one of these your in luck.You'll see a
small grouve cut out for pressure on the bottom half of the crankcase. The grouve
isn't big enough. You'll have to take a Dremel with a metal milling tool and make
it bigger. I made mine big enough so you could lay a 9/64 drill bit in the whole
grouve. I tried making smoke with just the grouve as it was from the factory. All
it would do is make smoke at 1/4 throttle and that was it. After i made it bigger
it worked 400% better. Making this hole bigger doesn't affect the engines performance.
Make sure you put a little bit of Loctite(i just use the light 242 stuff)on the fitting
threads upon final assembly.(the bell crank for the throttle assembly isn't worth a damn. Too much slop. I made a bell crank out of 1/8 aluminum.A little bit of overkill but there's no slop now!)MAKE SURE YOU GET ALL DIRT AND FILLINGS
OUT OF YOUR CRANKCASE BEFORE PUTTING IT BACK TOGETHER. FILLINGS DESTROY ENGINES
(If your using a B&B Smoke muffler or any kind of muffler where the muffler stacks just thread in, take them out and get a machine shop to make metal ones only get them to make the threads as long as possible. If your muffler has steel stacks your all set.Steel holds more heat than aluminum. The secret to getting great smoke is to get the oil to get as hot as possible and stay in the muffler for as long as possible.Aluminum pipes work very good also but steel is better. Also get them to weld the stacks in or else they will fall out due to vibration (if your running a gasoline engine).
Next you should mount your pump as close to the engine as possible. I don't think it matters how the pump is mounted(y,x and z axis).Notice on your two fittings on the side of your pump. There is an arrow indicating the direction of flow of the oil. The arrow pointing to the middle of the pump is hooked up to the line that goes to the valve then to your tank(I wished i could show you a diagram. I will try to have one in the future).The fitting with the arrow that points away from the pump goes to your muffler and of course the fitting pointing out of the pump in the middle is your pressure fitting that is hooked up to your crankcase for the suck/blow action that moves the oil(this pressure line should also be of the large neoprene type. To get some visit your local snowmobile/saw shop dealer or any small engine shop).Your tank should be mounted directly on the CG(center of gravity). In other words you don't want the balance of your plane to shift when your smoke tank is full or bone dry(it will be dry most the time because a 12 oz tank won't last much more than a minute!). Also you will need to install your gasoline stopper as well as a three line system. A three line system consists of a vent line, a filling line, and a pump line(line going to pump).To do this you just have to punch out another hole in your stopper. The vent line lets air in the tank so it won't make a vaccum. The filling line is for filling and draining the tank. The tank doesn't have to be wrapped in foam but I do because smoke oil can do a good job on radio equipment if it ever leaked out.Your filling line should be neoprene(the black stuff) because it doesn't get stiff when you run oil through it. Since your going to have to plug in your filling pump connector it makes it alot easier. Also it is easier to install a fuel line plug into. You'll have to plug your filling line because it will leak like a seive if you don't. Don t plug your vent line or else it will create a vacumm. A fine thread screw works good for a plug or you can buy plugs from your local hobby shop.
Install your valve. There are directions on the package as to the on/off setting.The Du-Bro valve comes with a bunch of neoprene which is what has to be used going through the valve.You will not need to run the line through both groves. One is sufficent.Don't forget to run a line from your pump to your muffler. Use neoprene for this because it will grip the muffler's fittings better plus it stands up to heat a bit better.
With your servo,valve,pump,tank,and lines installed, put some oil in her and fire the beast up. She should put out so much smoke it'll make your head spin. If you have any problems, questions or comments please e-mail me and i will do my best to help you. Thanks
