Nats and F2D
by Mark Rudner
rudner@mit.edu
The Control Line (CL) Nats and US F2D (CL Combat) Team Trials are right around the corner. In case you are still undecided, I urge you to go. Just do it! This is our premiere event of the year, so if you want to support the sport, this is your moment.
To show the AMA that we are serious, and to secure support for our national CL Combat team, we need to have a good turnout at the team trials. Come fly, have a great weekend of Combat, and show your support for the CL Combat community.
Engine Maintenance
In keeping with the how-to theme of this month’s issue, I’ve decided to dedicate this column to engine maintenance. Of course, it is not possible to do the entire topic justice within a single column, so consider this part one of a series of an as-yet-unknown length.
For those who might not be in the habit of regularly opening and disassembling engines, it’s natural to be slightly nervous about messing something up. It’s actually quite straightforward, and by keeping your engines in tip-top shape, you’re bound to fare better in the circle. Follow procedures and use common sense (no shortcuts), and you’ll be fine.
To make sure that everyone is on the same page and to build confidence, I’ll start with a basic decarbonization. I’ll cover deep cleaning and changing the bearings in a future article.
When you run your engine on castor oil fuel, carbon residue can build up into a thick, black layer on the piston and head and degrade the engine’s performance. Fortunately, it’s simple to get rid of in a matter of minutes.
To begin, remove the plug from the head then loosen the head and take it out of the engine. Be sure to keep track of all of the shims and do not bend
them. Next, you’ll need to remove the backplate. In many engines, the piston skirt fits into a slot in the backplate when the piston is at the bottom of its stroke. In this configuration, the backplate cannot be removed; therefore, before you try to pull out the backplate, be sure that the piston is set close to the top.
Now it’s time to remove the cylinder liner. If you’re lucky, you can simply slide it out with one finger. However, if it doesn’t budge, tighten a propeller on the engine. With the piston at the bottom of its stroke, insert a cable tie down into the cylinder. The aim is to get the clasp end of the cable tie into the exhaust port (see the photo). Turn the propeller so that the piston pushes up on the cable tie and pushes the cylinder out of the case. (The soft, plastic cable tie won’t damage anything.)
Finally, reach in through the back of the case, pop the rod off of the
crankshaft pin, and let the piston fall out gently onto your hand or workbench (see the photo). As you can see in the picture, the engine that I used for demonstration had a lot of carbon buildup on the top of the piston and the head. This will all be gone in a few seconds.
My weapon of choice for carbon removal is the Mr. Clean Magic Eraser. Mike Willcox turned me onto this miracle sponge. Cut off a small piece of the Magic Eraser and slightly dampen it with water. Applying gentle pressure, rub the head and piston top to wipe away the carbon buildup.
As simple as that, your head and piston top are shiny—like new. Now you simply need to wipe the parts dry and reassemble the engine.
When you reinstall the piston, be sure to do it with the proper end facing back. On a Fora engine, for example, one side of the piston has a longer skirt. This side always faces the rear. Before you push the connecting rod onto the crankshaft pin, add a few drops of oil to the pin (you might need to rock the crankshaft back and forth a little while gently pressing the rod onto the pin).
Next, install the cylinder. It is crucial that you have the cylinder properly rotated to align the ports when you push it down into the engine. On many (most) engines, there is a small pin in the case that keys into a slot on the flange of the liner to fix the alignment. Make sure that when you push the cylinder into the case, the pin goes all the way into the slot.
Finally, throw a few drops of oil into the cylinder, set the head back in (being sure to replace all of the shims that
When installing the liner, be sure that the notch in the flange aligns with the pin in the case, and that the liner seats all the way down into the case.
were there when you opened it up), and reinstall the backplate. Be sure that all of the shims are seated flat on the flange of the liner and not bent or sitting askew. Double-check that the backplate screws are tight.
That’s it. Your engine is now clean and ready for action. In a future article, I will discuss how to clean and change bearings.
Phoenix Shout-Out
Finally, I just want to give a big shout-out to Lance Matassa, Arlene Pyles, Jeff Hanauer, and the whole Phoenix crew for putting on another great F2D March Madness competition this spring. This year we had the biggest turnout to date, with 34 entries in triple elimination F2D. We had many exciting rounds and finished at dark.
The final standings were Mark Rudner, first place; Cary Minor, second place; and Alex Prokofiev, third place. In Friday’s F2D Fast competition, which also had an excellent turnout of 27 pilots, Andy
Minor took first place, while Jeff Johnson and Chuck Rudner placed second and third, respectively.
See you at the Nats!
SOURCES:
Miniature Aircraft Combat Association (MACA)
www.mac asite.org
Mr. Clean Magic Eraser
(800) 867-2532
www.mrclean.com/en-us
