it's more so the piston to the sleeve :sneaky:

I repeated this until I get hasted of saying it... now, simply I promised to myself to not repeat this phrase. The unique advice I say is to not leave any engine on the hands of someone he's capable of balancing a 1 cilinder engine. because is impossible.

I can sugest you take one of old crancase which you are not going to use, cut it I showed on attached pic, then install new bearings, make sure you don't lubricate them while you balance your work ( then for storage better to lubricate), now you can do your balancing work easier.

Alfonso, it is impossible to do perfect balancing, but it is possible to come pretty close, specialy when we know our usefull range of RPM (when motor is loaded) is pretty narow-between 26K RPM and 42 K RPM. Yes there is very good balancing numbers which make big difference. Just look any of performace 21 engines-they have tungsten inserts on counter weight-this is done to improve balancing. There are many different ways to improve balancing just need to get hands on it.

thanks dude, cool to see that

EdwardN: nice idea, limited machining, good precision.


mugenb46: I guess we are one step closer now.

when you balance these motors for an RPM its balanced.....for that RPM. So if you balance it at 38,000 RPM then it will only be in blance there and out of balance everywhere else, you cant balance these motors for a RPM Spectrum. Its a set RPM area as in 1-2K RPM, not 20K. You absolutely can not balance these engines any further than that. Ive seen modders engines vibrate worse on a dyno than stock....and they claimed to fully balance the crankshaft, ive also seen other modders engines act like stock, no one is balancing them, they may put it on a machine that spins it and say the balance it, but its a big BS fest as far as that goes. Trying to balance these engines is a waste of time and money as you cant do it.

that makes all the sence in the world to me, dammit i'm pissed thats it i quit lol. but how does it get out of balence from one rpm to another, or is it a harmonic balence, that i know some shit about. when you run 30,000 dollar motors in cup and arca cars they have a range were they perform in the perfect balence around 9000 to 9800 rpm this is short track rpm 6500 to 7500 rpm talledaga or daytona the motor is not in it's harmonic balence range. because of the gear they make us pull :sneaky:

yes im pretty sure its harmonic balancing done at the factory, EB Mods claims to balance his this way but its a flat out lie.

I am not going to argue with you. You might be right-I don't know on what info you base. I know what we are doing and how we are checking if it is pretty much balanced. On RC cars you can't really feel it-you are far away from thr car and it is moving fast, so there is no way to check it, but I will get back to where I came from, when you fly control line airplane and engine is not balanced then you feel itching on the control line handle. If somebody fly control line airplanes they will know what I am talking about. So we do make design, try it on airplanes, on different range of RPM (Please don't ask how we mesure it-we have way up to 10 RPM accuracy), Then change design and fly again, and agian and again, after couple of tens samles collected, just make analizes and it is pretty much fit to certain system, which just use common sence can be converted to formula.. Then, just one more time control test and it is ready to go. This is the way how we came to the cut on the pic. Sorry for quality of pic, but this the best I could do.
I am leaiving this up to you to make judjemnt-if we are doing balancing right or no-you can call it BS, or whatever, it is not really bothering me. I know what we are doing and I know phisical results. Balancing can be done very good and averaged to very wide RPM range. We fly on from 25 K to 42 K and it makes a lot of difference compare to regularly static balanced. We tryed all kind of engines, with all kind of modding. No how much difference it is on performance-this is triky question_ i will leav it up to you to decide. :rolleyes: :rolleyes: :rolleyes: If you want to know more obout this talk to Matkemiers brothers-they are really know balancing and they are the mentors on balancing for a lot of engine designers.

Who are you? someone from Axial? All of my information was from Brian Kenny @ Nitrodyne Systems AKA mxwrench on here.

I am just the guy, who is messing with nitro engines since 1976. Learn here, there, you know how it is happened. I know Brian Kinney very well-he is one of my best friends.
And brian info is absolutly correct we did discause with him this many times, but the difference is that our aplication is slightly different to what you try to bring as sample-motorcycle, so it is different leverages on cranck, diffrent RPM, different ratio HP/capacity etc. In motorsport they develope a lot of really good thing, actauly most o it, but all of them just simply can't be transfered to niro engines.So if any time something is taking from motrsport-there is defenetly need corection to fit our needs in RC

LOL, he is the Designer of Axial engine..

BTW, how u going Ed? drop me a PM or Email if you have time

Tommy

figures, i dunno why he couldnt say that tho.

He should'nt have too... :tire:

RC_Alan