Hi-

I’ve been flying electrics for the last couple of years, but now want to try a .40-sized IC powered ship. I’m already sold on the idea that I want a 4-stroker for a number of reasons, one of which is the reduced amount of fuel to clean up at the end of the day. From what I learned from this board, fuel is expelled from both the crank vent and the exhaust. Some engines have routed the crank vent to the carburetor, which greatly reduces the amount of unburned fuel dumped into the air and on the plane.

My current setup is a GP Cessna 182 with with a brushless motor and 15 cells which turns a 13X10 prop at about 7,400 RPMs. Doing some Mickey Mouse math, I figure that this setup is about as powerful as an O.S. FS-52S (0.83 HP; 530 watts, 4.91 lbs of thrust). Unfortunately, running time is a bit low at ~ 10 minutes. I’m happy with the power of the electric setup, but I’d like to fly longer (I’m fortunate enough that no one has the same frequency as I do at our club).

1) I was an auto mechanic in a prior life, so routine maintenance does not bother me. However, I hate cleaning - what is the cleanest engine in this class?

2) Any ball park figures on running times? This plane came with an 8oz tank and I typically only use full throttle during takeoffs.

Thanks in advance,

Paul

Hey Paul,

All glow engines will make the same oily mess comparatively, its the fuel content that contributes to that. A fuel mix comprised of synthetic oil will leave a small amount of residue compared to one with a large amount of castor oil in it.
I use a 15% Nitro- 18% Oil (100% Synthetic) Fuel mix, but add approx. 3 oz of castor oil for a 20% oil content. A small amount of castor is beneficial if you should have a "lean" run. If your OS 52 engine is new (For Break-in) or if you plan to use a Saito I would use a fuel with a little more castor oil in it up to 5%. Saito's do not have an aluminum bronze bushing in the connecting rod. Castor oil is cheap insurance if you don't mind a little mess.

An 8 0z tank should run a 52 at full throttle for about 12 minutes.

Happy Fly'n....

If your running your engine at the correct needle setting, they will all put out about the same amount of oil residue. If it's not throwing oil, it's too lean and your engine won't last long. Rather than try to avoid getting oil on your model, look at better ways to clean it quickly. Do a search on cleaning, you'll come up with a lot of ways to clean it off. I mix my own cleaner, one oz. dish detergent, 16 oz. Isopropal Alcohol, 111 oz. water. It cleans very well, and I use the cleaning time to look the model over for any obvious problems. By the way, I prefer the OS four strokes for their reliability.

PaulF:

Or you could use a real gasoline engine. 23cc to 28cc would weight just aboutthe same as your electric, and be more powerful.

Bill

Runs as good as any engine I have seen! Leaves VERY LITTLE residue on the plane-

6 oz. about 12- minutes depending on throttle management- Mine is on a Magic

Good luck!

Which direction you point the muffler can have as much effect on the amount of goo as anything. With a 4 stroke muffler, you sometimes can get the exhaust heading away from the plane and you don't have too much to clean. I've also had good luck with the exhaust deflectors that go on the end of the muffler on 2 strokes.

Larry

I use an 8' silicon tube sold by either Dubro or Dave Brown that attaches to the muffler and attach the other end to my landing gear so its always blowing the exhaust downward. Works real well cost less than $5

dpsper:

I use "Aerotrend" tubing for just that purpose. Makes a whale of a difference in the mess.

http://www.aerotrend.com

The silicone tubing comes in several sizes, ID from 1/4" to 3/4"and standard length is one foot, longer by special order. Just one item in their line.

It also works very well for a fully enclosed engine. I've attached a picture of the right engine nacelle of my "Tiggerkitty," the exhaust is the pipe in the upper left.

You do have to test when using these pipes, some engines do not want to run well with them.

HTH.

Bill.

PS: Due to the higher exhaust temperature, these pipes are not recommended for 4-stroke engines. wr.

I use the Aerotrend silicone tube with an OS 52FS on a Morris the Knife. The tube is 12" long and diverts the exhaust to the underside of the fuse. It makes a huge difference. The only mess in on the underside of the profile fuse and a little on the rudder.

Although Aerotrend says not to use the blue silicone tube with 4-strokes, it works for me. The silicone does cook a little at the muffler. When it starts to crack (after 10 to 15 flights) I simply cut 1/2" off and re-attach it.

Jason

Gentlemen-

Many thanks for the replies. Earlier today I ordered a Saito 50 and all the required ground equipment. I'm eagerly looking forward to trying this new setup. I think the Cessna was setup to direct the exhaust away from the fuse; if not, I will try the silicon tube method.

Pepe & Dave- I’ll exercise your advice on the castor oil and cleaning methods.

William Robison - was that a real suggestion or are you being sarcastic? The smallest gas engine I've seen is > 1.5 kilos; I wish they made them smaller.

Gent's how are you attaching to the muffler? Answer here or PM me please

Paul:
Dead serious. They DO make them smaller. Look at the RCS website for SMALL gas engines.

www.rcshowcase.com

Smallest one is 22cc, about 1.4 ci. Including ignition, 2 pounds, 0.9 Kg.

Also, see the l'Essence construction article in the May '03 issue of RCM - just arrived by subscription, may not be on the stands yet. He is using the RCS 1.8 gas. The 1.8 is 55 ounces, right at your 1.5 Kg.

HTH

Bill.

PS: For future reference, I try not to leave any question when sarcasm is included. wr.

My method usually is selecting the correct ID to be a tight push fit on the muffler outlet, sometimes adding a plastic tie.

Two places I did it differently.

The "Tiggekitty" has the tubes glued in the firewall with RTV silicone.

My "Diablo" with a K&B 61/Pitts muffler kept blowing them off, so I drilled through the stacks of the muffler and stuck a piece of wire through the stacks and both hoses. No more lost hoses.

HTH

Bill.

VERY nice setup, Bill. It's nice to see additional options when it comes to engines. I think I now have another reason to get that quarter scale Cub....

Cheers,

Paul