Around the Pattern
Membership
At the September Club meeting, a membership dues adjustment was approved. Through timely renewal and electronic receipt of the newsletter, most members will see no dues change. Various age brackets have been re-defined to align with AMA and State Park brackets. Each current member should have already received a membership renewal form. Contact Dick Stewart if yours has not arrived. Please complete all information and renew early – mail it in or bring it to a Club meeting. As of this printing, 103 members have already renewed. Renewals will be considered “early” until January 15th. All the early renewals will be entered into a raffle; three people will win prizes as an expression of thanks for renewing early.”
WRAM Show Club Bus Trip Signups Under Way
The annual Delaware R/C Club bus trip to the 2004 WRAM Show in White Plains NY will be on Saturday, February 21, 2004. Diane Hudak is organizing the trip. You can sign up for the trip at the Club Meeting on January 6, or contact Diane personally (phone: 302-366-0246 or e-mail: av8orsangel@delaware.net) to make your reservations. All those who have participated in past trips can relate stories about the fun that was experienced by all. The cost of the trip is $36 per person, which includes the cost of the bus, admission to the show, and light refreshments on the bus.
Field Maintenance Report
A big “Thank You!” once again to James Cistola! The Pavilion plastic wrap was damaged in the high winds we have been experiencing. James has some replacement material on hand and is leading a repair party that should have things “wrapped up” before the Freeze Fly.
Help Us Keep You Up To Date
In order to keep all our members informed of all Club news, it is crucial that the Club remain informed of all changes to our members’ contact information. Please send all changes of address and phone number to our Treasurer, Dick Stewart (302-368-2911 or BALTICPLY@aol.com). E-mail address changes should be sent to John Kirchstein (jakirchstein@comcast.net) and Carl Hauger (cewhauger@yahoo.com).
Classifieds
FOR SALE:
Great Planes Slow Poke with an O.S. FX .25 engine plus servos, no receiver. All for $110
Contact Del R/C member Herb Crossan 814-435-6314
Engine Troubleshooting, Part II
[Editor’s Note: this information was contributed by Rick Scott and was obtained through an Internet search. The source is unknown. Additional segments may appear in future issues of Glitch Busters]
Short, Long, Cool, Hot
Plugs are sometimes rated as cool to hot. The size of the filament is mostly what determines this rating however the length of the plug has some effect.
A cool plug means that it will not as readily ignite your fuel. This sounds like a bad thing, but not necessarily, timing is very important. If the fuel ignites too soon the piston will be at top dead center or maybe not even all the way up, this is called pre-ignition. (It causes spark knock or backfiring in automobile engines.) If you ignite the fuel too soon while the piston is at top dead center or before, you can damage your main bearings or the engine will stop on you. In this case a cooler plug may help delay the ignition.
The hotter plugs are hotter because they have a larger filament and reach farther down into the ignition chamber. (Warning: some engines may not be able to use a long plug, because it can hit the piston when it comes up. (This is rare) Always turn your engine over by hand after you change a plug.)
If ignition occurs after the correct point, compression is less so the fuel air mixture is wrong, you loose power or the engine quits. Four cycles have this problem because of the length of time between ignitions, i.e., ignition / power stroke - exhaust stroke - intake stroke - compression stroke - ignition /power . . . Due to the length of time the plug cools off and is slower to ignite the fuel.
Some plugs have idle bars, a small bar of metal mounted over the filament. This protects the filament from being cooled by the fuel thus the plug is hotter when starting. This sometimes allows a better idle.
I wish I could give you a rule to go by as to which plug to use, but there are none. There are too many veritable that effect what plug to use. It is another thing like fuel: start with what the manufacturer recommends then try everything else until something works…..
Other then having the wrong kind of plug you can have other problems with glow plugs.
If the plug burns out it is usually a voltage/current problem with your glow starter. Only use the kind glow starter that has a single battery built into the unit. Never use the glow starter built into power panels mounted on flight boxes. They are never right and will blow your plug in an instant, you can easily knock the knob out of adjustment and fry the plug too. Not to mention that they are unsafe, it is easy to get the wire in the prop.
If you are using a glow starter and still have bad plugs all the time your problem may be vibration, try balancing the prop or using (or not using) a soft engine mount. Some very high compression engines or engines that experience rapid throttle changes like on fun fly planes will blow plugs.
Another problem glow plugs have is the filament will be come clogged with oil or dirt, cleaning them works sometimes, but not often. Check the center connector on top of the plug, the insulator will sometimes crack or leak, bubbles around the plug insulator may be an indicator of this. Always check that the small washer is in place when you change the plug. This washer helps to seal the plug and lifts the plug up higher out of the combustion chamber.
Cracked filaments will not cause your engine to stop once the engine is running the filament will work even if there is no electrical connection as long as it is still in the plug. Of course it will not start your engine again.
Glow plugs also have problems with the screw threads striping on the engine. The threads on glow plugs are not always correct even though there is only one thread size. If the plug is loose or will not tighten you could be loosing compression. Unfortunately it is never the plug that strips, it is usually the engine. They do sell dies to re-thread glow plugs and it is a good idea to run the plug through the die to make sure it will not damage your engine.
If you are having problems with idle or low speed running and nothing seems to work you might try an on board glow plug starter that turns on whenever the throttle is set low. Note: This can be dangerous. Your engine could start when you don’t want it to. Be careful not to turn your prop with the power on, unless starting.