Hi to all
i have a question what is the BIG difference between FB rings to the original ones?
why peaple run to change there original ring?
why to open a brand new engine and replace the ring?
is FB rings made from gold or diamond?
i fly for many years gas engines without FB rings always use 32:1 synthetic oil for normal fly and for run-in i used 32:1 mineral oil for the first gallon
so far my engines are running like new,seriousness i can'tunderstand the logic behind this

Happy flying

ilan</p>

i think just on the china made engines guy's have been changing the ring,me included.FB rings are made from a softer cast material and seat better on a not so well machine cylinder.also his ring gaps run from .001-.003 at the largest,the biggest gap i had from any of his rings was a tight .002 and you always get more compression with his rings. the china made engines or any less quality, high dollar engine can run from .014 to .030.they also have a lot less tension on the cylinder wall,makes a smoother running engine.as far as opening up a new engine for me it is always better to start off with a new cylinder along with a new ring,no wear patterns from the ring before.
not so sure if they are needed on a better built engine like 3W,DA,Brison,BME.

+1

Yak 54, considering you are from Israel you may not want to spent the money buying a new piston ring from the USA, if you are happy with your engines that's great.
For the record I use Bowman rings for the reasons Closetguy mentioned, the extra cost is next to nothing considering what most of us spend on an airframe.
Last order I made had 4 rings and the postage was only a few dollars to Australia, well worth the money.
If they were made of gold or diamond they would be a lot more than $12

I have no China build engine, yet every engine bar none that I have put a Bowmnan ring in showed a marked improvement in performance from the very first start up.

Karol

what engine have you been using them in,just would like to know if it makes a difference on the top self engines too.
i have DA's and BME's also, and would like to know if they could use a FB ring.

I have placed Frank Boman rpiston rings in my &amp; my friends gas engines andhis rings havethe best fit &amp; the material is very good. Every engine ran better &amp; smoother. I have a DA Desert Aircraft 50cc engine. The compression is good but the ring seems rather narrow as the fit in the ring grove seems to be very loose. This makes a click you can hear at the exhaust port and cansee the extra "play" the ring has in the groove as you wiggle theprop back and forth. I will most likely replace it. Capt,n

Frank makes rings for just about every one of our hobby engines and I have been using them for several years, and have installed them in Italian made Super Tigres, Zenoahs and DA engines.

Karol

"If they were made of gold or diamond they would be a lot more than $12 "

Probably more like $15. Franks seems to love what he does. I doubt he is making anything given his prices. I priced buying the correct cast iron bars to try my hand at making rings but could not justify it based on what the raw material cost.

I had heard about this when I bought my first DLE20 so I called Valley View RC when Jedi Jody still worked there. He told me that the first bunch of engines had had and issue with hard rings so it took longer to break the engine in but at some point they had gone to a softer material and that the ring replacement was no longer really necessary. Unless you really really want to milk the last bit of power that this engine can give I think you will be fine with the stock setup. I know I am having no problems with mine...........of course I'm not racing or hovering or whatever........I'm just flying.

Couldn't agree more. Me too. My engine is working great, as are all of them I have first hand experience with.
-Al

the extra rpm is only the small part of the advantage for me,100-300 more rpm.it's the better seal,much smaller ring gap,and a lot smoother running.
thats why i didn't realy know if there was a advantage in a better quality engine,but from the reports i guess there is a advantage with those too,for 10.00-12.00 bucks it's money well spent.

We replace them on the new DLE's too. I'm not a machinist but our engine guy builds racing engines for a living and he uses FB rings on his engines and says he can see the quality difference just by looking at them.

Now if Frank would just chime in and tell us a little about how in the heck he makes a piston ring.

thats the 6 millon dollar question.i have ask two different machinest, does he cut them out of flat plate or does he use roll stock,they had no idea.
would you put it out on the internet how you made them?

He has told how he made them at one time in the past.

They are made from Mehanite bar stock. He told to what size he made them and cut etc.

Ditto here as well. Frank's rings on my Ryobi conversions turned them into different engines.Also use them on Zenoahs, Quadras, and a Chicom CCRC 40.

Many years ago, I believe it was engine expert Clarence Lee who said that Fox engines felt like they were high compression engines when in fact their compression ratios were moderate. He said the reason for that was because Duke Fox made the rings round in the same fashion that automobile piston rings are made instead of the typical way model engine rings are made.
I have no idea how car piston rings are made but if someone in here knows the answer he could give us a clue.

Hello All, I don't normally post on very many sites but I was asked to describe how I make rings, and the difference between my rings compared to other rings. After reading some of the other posts I just want to say if you are happy with your engines that is great, happy flying. If you want more performance with smoother lower idle, more peak RPM, better compression and lower operating temperatures then maybe you need a different ring. Manufactures generally make rings oversized, cut pin notches & slit rings with various sizes of slitting saws so when rings are installed the ring will close gap. Often pre load tension in rings is too much to try & force ring to seat in cylinder. Their machineing methods sometimes will cause rings to be out of round or uneven. By the time the ring seats ring gap widens and during operation that much tension just heats engine more than low tension rings like mine. My rings are round to begin with so I don't need to force them to seat and the low tension prolongs ring life with lower temperatures during operation. I will tell somewhat of my methods of making Piston Rings but please understand there is a lot more involved than what I will discuss here. I make my rings from solid fine grained cast iron bar stock. My finish cut on outside diameter of ring tube is .002. I machine the O.D. to exact cylinder bore dimension. This will insure a round ring without grinding OD. After finishing I.D. I part off rings from machined tube, ring thickness + .002. I use a feeler gage in Piston Ring Land to determine what correct top to bottom ring thickness should be. I hand lap ring to correct thickness, cut in anti rotation pin notch in rings if pistons are equipted with pins. Then I use a custom made tool to snap ring. I then stack rings on jig, secure with tie wire so rings stay flat on the jig during heating process. I place an outer sleeve over the rings and mount jig on my home made turn table. I then spin jig slowly while heating outer sleeve to a little over 1,850 degrees F, red hot. Radient heat goes through outer sleeve to rings stacked on jig. After slight cooling remove rings from jig to cool. I then hand file ring to get .001 to .002 gap to a bore gage that I make for every ring size. Cast iron is the one of the least expanding metal during the heating process soo ring gaps need to be kept tight as possible as all other metals from steel, aluminum, plated metals, chromed metals all expand more than cast iron. There is a lot of confusion as to ring gaps, which includes large gaps for lubrication of cylinder walls, etc. I have found large gaps allowing hot gas to escape down into crankcase and just heats engines more. All I know is a tight ring gap doesn't affect lubrication but does increase power. Loose gap means lower compression, less power, higher idle, lower peak RPM. I have made thousands of cast iron rings for Gas, diesel, glow fuel, 2 cycle, 4 cycle, marine, motor cycle, snow mobile, engines all with tight gaps. I'll let my customers tell what my tight ring gaped round rings do for their engines. There are 2 employees in my business, My Wife & Me. I get my insperation & guidance from my Lord and always try to deal fairly with all in my business. All I wish for is to make the best ring & do the best I can in everything that I do. Thanks Frank Bowman

You might as well post how one can get your ring's as well.

This is a good subject to do some test on. I have two RCGF engine's,20cc in service and broke-in, andone new. Also the same with a RCGF 26cc. Also a Dle, one broke in and one new. And the same with CRRC 55 twin's. I'll see if I can get with Mr. Bowman and get ring's for allfour new engine's and see what the difference between stock and new ring's are. How's that sound?
E-mailed Mr.Bowman.

I forgot to mention, The Lord & I built my business, I'm am a proud American, Viet Nam Vet, Army 173 Airborne 1970-71 and my rings are made here in New Mexico, USA. Take Care to all. Frank Bowman

Frank is a very good fisherman also. I have had the privilege of talking with Frank about Engines, how he makes Piston rings and Trout fishing. I know he is a Good man, as I talked with him I could tell he really does Trust in the Lord and it is good, for more people too doo the same. Like Frank says...do your best in everything. God bless you Frank...your quite a Man, no dought about it. Capt,n

>> I have redone the reed block mod and insured that the reeds do not show any air gaps when wet. They are slightly bowed, but do not show any air gaps. I also soldered the hole in the choke plate closed. The plane sat for almost 3 weeks without running. When I took it out last week, it pulled fuel and popped with the choke closed after 7 flips and started after another 7 flips with the choke off. Low end was very good, transition and mid range are improved so I conclude that the Bowman Ring, Reed Block mod and closing choke hole made this DLE 30 much easier to start and it runs better on low, mid range, and full throttle. Well worth the effort IMO. >>>

Here's a post from Flying Giants that I borrowed. Hope that's legal!

Nicely said Frank.How in the world do you keep up with your work?
I finally got check mailed off for the rings for the Rear Exhaust DLE 30&55.
My flying friend Dan from Duboise caught a 12 lb Brown in the Wind river a few days ago and then a 6 lb a day or so later.I will try and post a picture when I learn how again.My brain lost a lot of things when they had me in a coma for days.It was not too good in the first place. Have your rings in all of my DLE engines seven I think.Got to go flying last week end ,weather hear is beautiful glad I do not live in the East rightnow,
God Bless, BCCHI (AMA 2500).