I'm new to this hobby. I have a Piper Cub that is about 85% done. My plan is to mount the engine upside down. I have a K&B .45 engine that is about 7 yrs. old and I just got done breaking it in since it was never used. Basically, it's new. I went to the hobby shop to get the engine tuned because because I couldn't do it myself. I found out the glow plut was crapped up and I had the low speed disc setting too rich. My hobby shop guy told me to get a special glow plug (one with a bar near the coil) if I was going to mount it upside down.

Q1: Will I have problems mounting this engine upside down. My reason for this is because the head doesn't stick out of the cowl when it's upside down. The WHOLE engine is in the cowl.

Q2: Will I have heating problems because the engine head is not sticking out of the cowl. My plan is to cut out some holes in the front of the cowl to let some air in to cool the engine as well as to vent the carb. Also, I plan to cut out a hole at the bottom part of the cowl to have an outlet for the hot air. Basically, air goes in through the front holes, and out the bottom hole.

Q3: I just broke the engine in today according to the manual. It said to let it run on a rich setting for about one hour. I did that. It took about 5 refills to my 10 oz. fuel tank. This is different from what the hobby shop guy told me.
My hobby shop guy told me to run it rich to where I can touch the head, then run it lean till it heats up and you can't touch it anymore, then run it rich again till it cools. Keep doing this for 5-6 refills.
I tried the way the hobby shop guy told me, but I didn't know it was too hot to touch. Heck, even at the richest setting it was too hot to touch for more than 2 seconds. I got frustrated and just broke it in the way the manual says because it was more objective.

Well, thanks in advance and I'll post more questions in another post as not to crowd this one. I hope I used terms that you experts can understand.

It will be fine. The only issue is it may drip because the carb is lower than the tank. Mount the tank as low as possible.

Sounds fine as long as there is enough airflow. Run the engine without the cowl for the first few flights. Then add the cowl. If it loses power, then heat may be the problem.

Running it without the cowl at first will helps as it will be easier to adjust the carb.
I have never seen an engine that could run that cool. It is also good to stop, let it cool then run again. The heat cycles are part of the break in.

More questions from the newbie

Q4: I plan on setting the throttle and servo system to where when I put the throttle trim all the way down and pull the throttle all the way back, it closes the throttle completely and shuts off the engine. The problem came when I found out that when I put the throttle trim all the way up (as to not shut the engine off when I pull all the way back on the throttle), and pushed the throttle stick all the way up, the servo wants to move the throttle arm on the engine past it's upper extreme. Basically, there is not enough slack. Is there some device that can solve this. I was thinking I could implement some type of spring system to where when I push the throttle stick all the way up, the spring will take up the extra movement and not drain the battery.

Q5: The engine instructions said not to use anything over 15% nitro and less than 18% oil until the engine is broken in. I used exactly 15% nitro and 18% oil when I broke it in today. Is there a problem with this. I used it because it was what I bought before my hobby shop guy told me that he usually uses 10% nitro.

Q6: The engine instructions said that the midline for the fuel tank should be 1/8"-1/4" below the fuel line connection to the engine. It is difficult for me to do this because the engine is upside down and the fuel line connection to the engine is quite low. The fuel tank would need to be all the way to the floor of the plane (if even possible) for me to conform to the instruction. Would it be a problem if the fuel tank midline is level with the connection or even a little bit above it. What is the reasoning behind what the instruction says?

You need to reduce the throw. Either use a shorter arm on the servo or adjust the ATV on the transmitter. Since the trim effects the full throttle setting, I assume your radio does not anve adjustable travel (ATV). The small wheels that come with the servos have several holes. Some are closer in.
I use 15% for everything. 10% gave me very poor performance on some engines. I always recommend using one fuel and sticking with it. Changing it after break in is not a real good idea. Some enginse seem to develop a preference to one fuel.
Get it as low as easily possible. If it is higher it will not be problem. Like I siad before, the carb may drip as the fuel free-flows when it is not running. One nice thing with the engine inverted, is this fuel will drip out rather than fill up the crankase.

An engine mounted upright and the carb lower than the engine would be a problem. It will likely flood before you get it started.

For cooling, 150% OUTLET AREA FOR A GIVEN SIZE OF INLET AREA.
For the throttle problem, a snug fitting piece of fuel line (1") over two pieces of pushrod, make sure the rod extends past the fuel tubing 1/4" on either side. Connect to carb, and servo, the "excess" movement will be taken up by the sliding action of the tube/pushrod.

Jetts

geish,
First things first. Welcome to RCU and RC flying. Great hobby with a lot of terrific people.

Second, do not try to fly alone. It is much more difficult than you might think, and I don't want to see all your hard work destroyed after 20 seconds in the air.

Find a local club. They'll have instructors who'll help you learn to fly. No cost and they'll keep your plane in one piece.

Now on to the plane. A Piper Cub has some idiosyncrasies that don't make it all that easy to fly. You'd be much better off getting a trainer to start.

Okay. Your questions:
1) Mounting the engine inverted. You've gotten good advice. Do watch the height of the tank; once the fuel gets flowing, your tank will empty itself through the carb.
2) As Jetts said, 150% airflow out. (If you cut a one inch hole in the front of the cowl, you'll need three inches in the rear.)
3) Your engine is broken in now. Not much you can do to change that. BUT, it sounds like you did everything right, and the fuel you're using is fine too.
4) Get the pushrod as close in on the servo as possible, and as far out on the engine's throttle arm as possible. This will keep the throw as short as possible. Then you can try other stuff if it's not enough.
5) Refer to #3 above.
6) See #1 above. You normally want the center of the tank to line up with the throttle barrel. It most likely won't be possible mounting inverted. But you will need to be careful about fuel syphoning out the carb.

I'd recommend mounting the engine on it's side, or at a 45 degree angle. It'll be much easier in the long run. Both for running, and for the fuel issue. As a newbie, you need to reduce potential problem areas.

You never mentioned the muffler either. Did you get a "Pitts" style in-cowl muffler. If not, you'll have to cut a hole in the cowl for the muffler to stick out anyway.

I wan to say again. GET AN INSTRUCTOR!
Joining the AMA is pretty much required to fly this size plane. It will almost certainly be a requirement to join a local club.

Here's a link to the AMA site. http://modelaircraft.org/templates/ama/

Good luck,
Dennis-

"You never mentioned the muffler either. Did you get a "Pitts" style in-cowl muffler. If not, you'll have to cut a hole in the cowl for the muffler to stick out anyway."

I used the muffler that came with the engine. It DOES stick out of the cowling. I had to sand some of the side of the fuselage because the muffler was hitting it.

Let me just say that you guys are a load of information. I have never been in contact with such nice people. Once I get this built, I'll definitly join the club near my house. I live in HOUSTON if any of you are from around here. The nearest club from me is in George Bush Park. It's right next to the gun range, which I also go to.

geish,
Happy to hear you'll be looking up the club. But don't wait until the Cub is finished! Get over there tomorrow, early afternoon. (That's when most people are likely to be out.)

Introduce yourself, tell them about your Cub, find out who their instructors are, and if the instructors have preferences for radio equipment. (They'll have to be compatible for training purposes.)

You'll probably find the guys there equally friendly, and as full of opinions as we are.

Good Luck, and keep us posted.
Dennis-

geish

You have received a lot of good info from all above but most of all from DBCherry concerning getting involved with a club and mentor (I hate the word instructor, its not very descriptive of what this person will actually be doing for you). Glad to hear you
are taking it to heart.

First off I would just like to say an inverted engine mount is the least desireable in the training environment due to flooding/fueling problems and the ideal position for that airplane is sideways not up right. In a cub the fuel tank positioning is also difficult with an upright position and the inability to get it high enough. This is why in most cub kits and arf's the engine is mounted sideways.

Lets talk a bit about your engine. If it is a K&B and marked .45 then it is a Sportster. Now discontinued they were fine engines that received somewhat of an undeserved reputation because of some unique features not used by others. Built during the production years in sizes of .20, .28, .45 and .65. They are a plain bering engine that is not ABC, instead they are AAC. A High nitrate alloy aluminum piston runing in a sleeveless aluminum
cylinder that is chrome plated. It is for this reason that your engine is not broken in yet. It takes awhile but that does not means you cannot start flying, just that it will not be at its best for a bit.

By the way all Sportsters make a delightful rattling sound at idle and is normal. The other major differance is the type of midrange mixture adjustment used and many are not aware there is a midrange adjustment (it is not a second needle type or an air bleed) so it would be helpful at your club if you asked around for someone with K&B experiance for a hand with the engine.

Don,t listen to any one who says that Sportsters are just sea anchors, they are good engines I use a .45 Sportster on a trainer For cross country flights that carrys 50 ozs of fuel and done just over two hours non stop covering eighty miles, They are good engines.


Welcome and best of luck

John