This is going to be the best topic in a long time,
Glad to see you come aboard Allen.
I have to run to hospital for my mother in law,
but I will be back later tonight, Hang in there,

Wally
(Affiliation) RC-Aftermarket (Engine Modifier & Engine Designer)

I agree more heat more power, law of Physics you can't get around. If the fins are not hotter the piston is not either, (with the exception of combustion defects). You dont think by exposing the ring more,( by cutting the piston), you increase the rate of heat transfer. If the cylinder is cooler the transfer will be more rapid, how does that cause the piston to expand faster. If pistons expanded faster than cylinders the engine would seize shortly after start-up. On top of that the incoming charge is cooler which is bathing the piston first. What happens to alcohol engines, they have to run the engine for some time at almost full rpm to get heat in the engine before a run, without a cooling system. The reason racers warm the engine up is to get full power from the engine and not lose the btu's in warming the engine, but to make torque.

Chris

The piston has direct contact to the combustion as does the walls of the cylinder but there a couple of things you are not taking into affect.The piston face at the exhaust port is constantly being with heat from the hot exhaust gasses and since we run mufflers for the most part ,the heat at the piston face while the port is closed can be a problem if tuning is off(lean).

The cylinder is designed to dissapate the heat the combustion creates, when you put more heat to the piston when it is cold it will expand faster then the cylinder because it can't get rid of the heat as fast as the cylinder can.When you warm up an engine you are allowing the parts to expand more gradually and together.Once they get to there max expansion you are fine unless tuning is off. look up the term cold seizure, happens all the time because I see it all the time.

As I said before you don't have to heat cycle your engines and you don't have to warm them up, that is your choice but I have and will and my engines last a long time. Peace, Al

""look up the term cold seizure""

years ago I did this once with one of my G23s in a Boat oo-pss

Jim
Buzz Buzz Buzz

Break-in

What I usually do is start the engine and leave it running for the entire tank, no shutdown per say.

On a new heli I use adjustments to help with breakin:

I lift off, check tracking, land, adjust, repeat until right.
I lift off again, check tail rod length in normal mode for no drift and adjust as necessary.
I adjust throttle curves in normal mode to match gv-1, and only use normal mode for the first couple of tanks.

Once all adjustments are done, I fly around for 2 minutes, land for 1 minute and idle, repeat.

I don't use full throttle climbouts, just take it easy do circuits. I don't hover also the entire time. Flying around is easier on the motor than hovering.

I will climb out slowly to altitude as a fly around and autorotate down to have some fun in the process and rest the motor for a minute before liftoff again.

Do this for a couple of tanks, then next couple of take alternate between normal and idle up 1 speeds. Still take it easy on the motor.
Couple of more tanks run more idle up 1 than normal, do some easy aerobatics like rolls or loops without too much collective.

Gradually do more and after 1 gallon through the motor I'll start introducing idle up 2 speeds but sparingly and increase duration I use it. There are many maneuvers that you can do that do not require extreme loads to keep the fun alive, for example sideways flying, backwards flying, inverted flying forwards or backwards, piro flips, etc. I would stay away from tic tocs and full power climbouts and remember to land every once in a while to let the motor rest at idle for a minute.

After 2 gallons complete switch fuel from breakin oil if was using that and do anything you want to do, consider the motor broken in at that time.

That's basically how I do my motors, seems to work well for me so I keep the same routine for new breakin's. Will be doing the same for a new motor rebuild in someone's machine this week to get that all setup for them.

-=>Raja.

1005-G G26 3D Max, 3356 flts
Spectra-G G270 3D Max, 2228 flts
Whiplash-G G270 3D Max, 322 flts

Hmmm....

http://www.mototuneusa.com/break_in_secrets.htm

Dimitris

Hmm is right Dimitris76, I've got a brand new motor that I might try this to.

fly til its dry

these cylinders are not honed at all and these are not 4 cycle engines,plus these are not race engines. When i was building pro motox race bikes we would break them in quickly and would get max power out of them but top ends(piston and ring) would need to be replaced at 10 hr intervals for 80 and 125cc bikes. I'm am not disputing some of his info but he won't repair your engine if you cook it.

These are not state of the art engines, they are primative implement products adapted for our use. Peace, Al

http://www.motorcycle.com/how-to/wr...ation-3420.html

I have not seen an engine without honing, what holds the oil? The heat will transfer faster from a hot to a cold surface, hence the heat from the ring wiil be passed rapidly to the cylinder, equilibrium wants to maintained. The hottest part on the piston is the ring end gap, because of the discontinuity. You will notice the end gap is usually worn more. I don't doubt you have seen seen what you stated occurred, but maybe for different reasons. The piston would show cooked oil on the bottom of the piston crown if the piston got hotter than around 350-400 degrees because most of the oils we use cook somewhere at that temp.

Chris

""I have not seen an engine without honing""

my MVVS 35cc was not Honed !!

Jim
Buzz Buzz Buzz

Justin Stuart If everybody though along your lines we would not have the engines we have today. Engines have been around for more than a hundred years and advancements are made every day. There is still a lot not known about engines today. I never said anything about Al's engines I think he has a solid reputation, we are just discussing thoughts. Don't be so defensive of Al I think he can handle a discussion.

Chris

Justin Stuart If everybody though along your lines we would not have the engines we have today. Engines have been around for more than a hundred years and advancements are made every day.

Tell me this: How long have you been modifying Zenoah 23cc engines for? How much experience do you personally have modifying Zenoah engines for RC helicopter use? So why then do you think you're going to be the guy to come up with the "next great idea" when it comes to 23cc Zenoah RC helicopter engines?

All these motorcycle guys come along thinking they have some new way to run the exact same engines which have been used in this hobby for 20+ years. Well, just because it worked on a 125cc dirt bike doesn't mean it's going to work well in a 23cc Zenoah motor hard mounted to a helicopter with sensitive gyros and delicate electronics.

I see the same thing happen in these forums year after year. Some new guy comes along and thinks he's going to build a better mousetrap. Not meaning to be disrespectful, but why not just listen to Toxic Al's 20+ years of experience. He probably knows something more than you do.

What this hobby needs is a new kind of engine. Something not based on the same old Zenoah we have been using for decades. That's where the efforts should be made.

Avant RC
Scorpion Power Systems
Thunder Power RC
Kontronik Drives

Thanx Ra:

For Honestly and Sincerely laying the Cards Out

I let mine come to soak for 2 or three minutes prior at hover speed and settle back down upon touch down - till I hear it fall back.

I can tell by sound and literally by smell " Hot Dog's" and if the Lube is vaporizing or leaving a stench.

I hate chasing needles and do use my hover pitch and hover throttle adjustments depending on temp and humidity.

Thanx again Raja for contribution & confirmation !

Here's a pic that will catch some HEAT : Just after I removed the exhaust diaper and switched to pure syn / syn. )0( pitch smooth as warm oil - Don't reccomend if your a neubie :

Still have one set up question on servo resolution issue to de- sensitze one of my cyclic s - { SE } and if it will shorten servo life - maybe closer to spring I'll bring it up see If we can get a resolution. Can't whip it mechanically.

greyeagle

Still have one set up question on servo resolution issue to de- sensitze one of my cyclic s - { SE } and if it will shorten servo life - maybe closer to spring I'll bring it up see If we can get a resolution. Can't whip it mechanically.

not sure I understand your question. A very easy way to de-sensitize your cyclic is to simply use negative expo in your radio setup. That has no impact on anything to do with servo life. it simply changes the pulses that the servo sees and responds to

did I miss your real question?

If you're not flying a gasoline helicopter
You're paying 10 times too much for fuel!!

Justin Stuart You are not adding anything productive to the discussion.

Chris

Think you got it Carey: I'm just not sure If Expo is the answer.

Presently I run around 20% all around on a 1005 SE Conversion w / A pro head and standard CNc mixing arm's. Mechanically in the head - I have the throws set up as docile I can get it - along with the bell crank drive line leading up to it.

The cyclic handles' nothing like my standard and is just stinking red hot touchy even with a set of Hevey FAI's and standard paddles.

I do run a pretty High head speed 1800 + /- 1900 & + 6 to 7 degree on the cyclic all around

If I pile on the expo say 40% can I - de tune the aggressive cyclic?

I believe I tried it once - according to my card's and didn't get any noticeable results.

I was thinking the only thing left is to turn down the resolution from 100 to 80 or more >>> just to shorten the throw's -- give it a softer feel - but will it sacrifice the servo life ??

greyeagle

sure you can just lower the ATV's to get less overall travel

never heard of that ever causing a servo problem

with the SBus and other programmable servos, you can set the ATV directly in the servo if you want.

If you're not flying a gasoline helicopter
You're paying 10 times too much for fuel!!

I'll DO It !! no guts no glory -----My stuff is sold Old -9Cs- s Bus Technology will just have it faint.

I'm still using Frequency Modulation & Morris code

Could be interesting Expo + Lower ATV's

PS > Thanx For the Confidence ! Jack

greyeagle

I hate to ask this, but just to clarify..

When you say 20% or 40% expo.. You do mean -20 and -40% right...?
Futaba correct?