logo
Thread Tools
Old 10-03-2019, 06:00 AM
Viatcheslav is offline
Find More Posts by Viatcheslav
Viatcheslav
Joined Jan 2019
21 Posts
Thank you all for the recommendations, feedback, accurate numbers and so on ...
When ordering a ring with a clearance of 0.001, he hoped for an increase in the performance of the EME 35 motor as a result of which the “Swiss watch” did not work out.
After replacing the Chinese ring 0.015 with a new 0.008, the minimum and maximum revolutions did not change. Then a ring of 0.006 was installed; the maximum revolutions were reduced by 400 rpm, the motor power was less.
Yesterday I checked a motor with different screws and silencers and a canister. The EME 35 cylinder overheats when working with the canister. He made conclusions for himself.
I close the question on the ring with a gap of 0.001.
Have a nice flight.
Viatcheslav is offline Find More Posts by Viatcheslav
Reply With Quote Quick reply to this message
Sign up now
to remove ads between posts
Old 10-03-2019, 06:47 AM
KMatch is online now
Find More Posts by KMatch
Registered User
KMatch's Avatar
United States, TX, Bay City
Joined Nov 2016
584 Posts
If rpms dropped 400 with a lower ring gap your problem isn't rings unless it was improperly installed or damaged. Hoping for a measuerable increase in power chasing ring gaps on an unmodified, low performance engine shows a lack of comprehension in how engines work. This has been backed up with repeated evidence of not understanding manufacture tolerances as well. An engine overheating with a cannister is also evidense of a lack of tuning skills and prop (screw) selection understanding. I can fully understand the frustration of a business being "harassed" by a customer chasing rainbows with an apparent lack of understanding in mechanics.
KMatch is online now Find More Posts by KMatch
Reply With Quote Quick reply to this message
Old 10-03-2019, 07:28 AM
ponyboy082662 is online now
Find More Posts by ponyboy082662
wrongwayfeldman
ponyboy082662's Avatar
United States, AL, Florence
Joined Mar 2010
2,385 Posts
He made no statement about how long he let the Bjorn ring run....did he run it long enough to seat. No wonder his engine makes less power, he has no idea what he's doing.

Oh....and if his engine came with a .015 gap... His bore is .005 larger (as we suspected) than the .010 thoes engines normally come with. So if his engine is .005 larger than the .001 ring Bjorn sent him....do the math....001 ring with a .005 overbore = the .006 he was getting.
ponyboy082662 is online now Find More Posts by ponyboy082662
Reply With Quote Quick reply to this message
Old 10-03-2019, 07:37 AM
JoeT is online now
Find More Posts by JoeT
Racer, Flyer, Dad!
JoeT's Avatar
Canada, ON, Vaughan
Joined Oct 2013
1,211 Posts
Kmatch / ponyboy,

Totally agree, his last post clearly identified a lack of knowledge of how to tune an engine. Plus he completely ignored the message I posted asking for measurements in different languages.

Case closed.. IGNORE!!
JoeT is online now Find More Posts by JoeT
Reply With Quote Quick reply to this message
Old 10-03-2019, 07:11 PM
AKNick is offline
Find More Posts by AKNick
It's Tougher in Alaska
AKNick's Avatar
United States, AK, Juneau
Joined Feb 2014
363 Posts
Quote:
Originally Posted by Viatcheslav View Post
Thank you all for the recommendations,
After replacing the Chinese ring 0.015 with a new 0.008, the minimum and maximum revolutions did not change. Then a ring of 0.006 was installed; the maximum revolutions were reduced by 400 rpm, the motor power was less.
This is a great place to learn information and experiences from others if their is an openness to listen and teach. I'm a little disappointed in some of the attitudes here. So I'm sorry about that. Hopefully that's water off a ducks back.
The only thing I can tell you/ask (and was mentioned before) is how much time did you allow the ring(s) to break in? Should take a few gallons before getting optimum performance. If comparing a broken in ring and a non broken in ring I would expect the numbers to not be accurate right away. Another thing to keep in mind it a lot of cylinders, pistons, and rings actually break in together/better as a matched set, so swapping so many rings all the time isn't doing the engine performance any benefit in my opinion. Just my opinion.
Since you are fighting to get perfection, you may need to start over with a new cylinder/piston/ring. Gap it yourself since the mfgrs tolerances are not accurate enough to get a pre-gapped ring apparently (from what I'm hearing here?). Then break it in properly in the air, THEN check the numbers after a 10 tanks up to a gallon. It's takes time for these engines to wake up with a new ring sometimes.
Anyways, I hope you succeed in your mission! I don't think I have much else from my limited experience to help you, but happy to try!
AKNick is offline Find More Posts by AKNick
Reply With Quote Quick reply to this message
Old 10-04-2019, 02:21 PM
Cycletech is offline
Find More Posts by Cycletech
CycleTech
Cycletech's Avatar
United States, CT, Greenwich
Joined Jun 2019
145 Posts
I build high performance 2 strokes for a living and cant believe the amount of effort being put into one of these motors! Honestly I cant knock anyone from trying to learn and try to never criticize. Now with that said the OP needs to LISTEN to whats being asked. These engines are very low performance compared to what Im use to working with. A bore with .003" taper or Out of round is no good in my world because stroke and RPM values have us maxing out piston speeds to the point were that taper would cause ring bounce and flutter. I finish hone to within .0002"- .0007" on a cylinder as far as taper and consentricity. Anyway what Im saying to the OP is if you cant perform a basic 6 point bore inspection and subtract the numbers to find your taper and out of round then just leave this all alone untill you have become more educated on engine dynamics and concepts. Dont drive yourself crazy chasing your tail over a couple thou on your ring gap because honestly you have not controlled the verables to even come back with relevent results. Just run it and go fly.
Cycletech is offline Find More Posts by Cycletech
Reply With Quote Quick reply to this message
Old 10-04-2019, 03:18 PM
Frankieb is offline
Find More Posts by Frankieb
Registered User
Frankieb's Avatar
PR
Joined Mar 2007
95 Posts
It's beeing a great instructional matter. I learn a lot from it. I've purchased Jorn rings for 20cc and 55cc engines. No problem so far.
What is more interesting for me is the fact that buying a $15 ring the guy wants to make perfection out of a "economic" engine instead of looking for improvement. It is just my opinion.....
Frankieb is offline Find More Posts by Frankieb
Reply With Quote Quick reply to this message
Old 10-05-2019, 04:13 PM
karolh is offline
Find More Posts by karolh
Registered User
Mandeville, Jamaica, West Indies
Joined Aug 2007
615 Posts
Quote:
Originally Posted by Cycletech View Post
Anyway what Im saying to the OP is if you cant perform a basic 6 point bore inspection and subtract the numbers to find your taper and out of round then just leave this all alone untill you have become more educated on engine dynamics and concepts. Dont drive yourself crazy chasing your tail over a couple thou on your ring gap because honestly you have not controlled the verables to even come back with relevent results. Just run it and go fly.
Sound like some real sound and practical advice being given here
karolh is offline Find More Posts by karolh
Reply With Quote Quick reply to this message
Old 10-06-2019, 11:22 PM
RcwBone is offline
Find More Posts by RcwBone
Registered User
Joined Jun 2015
373 Posts
Quote:
Originally Posted by KMatch View Post
In the end I haven't seen a single reason why the engine wouldn't run just fine. I would love to see a dyno comparison between a 30-50cc standard design engine with .001" versus .005" and .010" all taken with the same engine back to back testing. My money is on the dyno not knowing the difference at anything above mid throttle. If I ordered and expected a ring with .001" gap I'd like to see that, but the electricity alone wasted in complaining is worth more than the precision being demanded in a 30cc every day low quality mass produced Chinese engine. In the end, that's all it is. We're looking for Swiss quality in a Walmart watch. The watch works fine and keeps time, but it ain't a Rolex regardless of how many shiny parts you throw at it.
Well my tests were done on a complexly difirent engine. I built a 822 CI mountain motor prostock engine a 4.78 bore diameter. I assembled the engine with a ring gap of .028 I then ran it on the dyno it made 1340 ft lbs of torque and 1837 hp. This was an avrage of 3 pulls. I then pulled the heads and oil pan. I re gaped the rings to .04 and ran it again. Made the same power. I repeated the same thing over and over again increasing the gap until I found a power loss of any measurable kind. I finally stopped at a ring gap of .155 . With this wide a$$ gap the motor still made 1835 hp and 1330 pounds of torque. So I would not give too $hits if I got a ring with a gap of .006 on any RC engine. This was on a $ 100,000 engine that holds the record for the quickest NA pass in a prostock car ever recorded. The record was set by Pete Berner in his Summit racing sponsored pro stock in 2010 if my memory is correct. He went 6.206 at 225 mph this was done with a .050 ring gap.
RcwBone is offline Find More Posts by RcwBone
Last edited by RcwBone; 10-06-2019 at 11:28 PM.
Reply With Quote Quick reply to this message
Old 10-06-2019, 11:48 PM
KMatch is online now
Find More Posts by KMatch
Registered User
KMatch's Avatar
United States, TX, Bay City
Joined Nov 2016
584 Posts
That's a helluva lotta work! What was the point? Was there really that much demand in gap testing or was this gapping due to some other test requirement?
KMatch is online now Find More Posts by KMatch
Reply With Quote Quick reply to this message


Quick Reply
Message:


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools