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Scale Furai - Scale 20B Nitro Engine

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Old 01-06-2009 | 11:44 PM
  #26  
BigRed's Avatar
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nice update!!!

Originally Posted by DailyDriver2k5
NOW that is cool!!!! Get some video and a sound clip if you can, I could imagine what a pint size rotary woulld sound like! What would the revolutions be on such a small motor,15,19,maybe 25k rpms give or take?
in response to this question, i couldn't even imagine. the small single piston OS engines get up to 50k, and now this one's a rotary. Assuming an average car goes up to 6k and a normal rotary goes up to 9k, and assuming the single piston OS engine is average, this baby will get up to 75k rpm whoa!
Old 01-07-2009 | 12:20 AM
  #27  
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The OS rotaries can't get anywhere near 50K rpms. They are capable of hitting 20K though and hit their peak power at 16K rpm. I have one! 75K. Dream on!!!
Old 01-07-2009 | 10:13 AM
  #28  
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Originally Posted by rotarygod
The OS rotaries can't get anywhere near 50K rpms. They are capable of hitting 20K though and hit their peak power at 16K rpm. I have one! 75K. Dream on!!!
Ahhh...my bad. When I had an hpi nitro car, they told me that the engines are capable of 50k. by using math, i assumed the same ratios guess not
Old 01-07-2009 | 11:42 AM
  #29  
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Originally Posted by BigRed
Ahhh...my bad. When I had an hpi nitro car, they told me that the engines are capable of 50k. by using math, i assumed the same ratios guess not
50K? HAHAHA! THat must be right before the connecting rod goes through the side.
Old 01-07-2009 | 03:59 PM
  #30  
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From: sevenONEfour
this is defintely a sweet project.

makes me want to do something like this, that would be pretty sweet to have my own r/c mini rx-8.

can't wait to hear more updates!
Old 01-07-2009 | 07:39 PM
  #31  
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Originally Posted by MikeTyson8MyKids
50K? HAHAHA! THat must be right before the connecting rod goes through the side.
ok. you think that. it's probably correct for the engine i had at least. refer to this: http://www.rccartips.com/nitro-engines.htm .

EDIT: sorry for "ruining" the thread. good luck, however!
Old 01-07-2009 | 07:46 PM
  #32  
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Brent Ive gotta check theis out in person,,, the next meet you come to make sure to bring this with you...
Old 01-08-2009 | 03:01 AM
  #33  
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You should contact some of the large RC manufacturers and ask for some free parts! lol A cool little project like this can attract attention from different people and what not. Get that car in a RC mag
Old 01-09-2009 | 09:13 PM
  #34  
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=O nice, really impressive work. please keep us posted good luck with the project
Old 01-09-2009 | 10:42 PM
  #35  
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Originally Posted by rotarygod
The OS rotaries can't get anywhere near 50K rpms. They are capable of hitting 20K though and hit their peak power at 16K rpm. I have one! 75K. Dream on!!!
Let's see it.
Old 01-10-2009 | 12:36 AM
  #36  
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Originally Posted by WhiteSnowflake8
You should contact some of the large RC manufacturers and ask for some free parts! lol A cool little project like this can attract attention from different people and what not. Get that car in a RC mag

I agree with this suggestion, to some extent. I think your work is exceptional and could get lots of attention from the general public.
Old 01-23-2009 | 09:47 AM
  #37  
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Originally Posted by EdwardsB
^ all depends on what you want to do. So far I have bought two used complete engines (OS 30 Wankel) for $170 each. They are around $350-400 new and you need 2 of them for a "13b" so far im up to ~$350 on the engine.

I have access to a water jet and milling machines for the center/side plates, if you don't its around $40 an hour to have it sent away. I have not looked into materials for the plates/shaft yet, but I do not expect that to be more than $100.



I'm not going this route but here is another option for joining engines...
What technique was used for joining these engines? Just an adapter "flywheel" like piece?

I am working on a similar project and I hadn't seen this thread....funny! Good luck on your project!

Best regards,

Chris
Old 01-23-2009 | 09:48 AM
  #38  
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Originally Posted by BigRed
Ahhh...my bad. When I had an hpi nitro car, they told me that the engines are capable of 50k. by using math, i assumed the same ratios guess not
Don't forget that real cars are 4 stroke engines, R/c cars are mainly 2 stroke so they rev way more by comparison.

Chris
Old 01-23-2009 | 09:56 AM
  #39  
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dam this is crazy!!!
Old 01-23-2009 | 12:47 PM
  #40  
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I had already posted this as a joke some time ago, but here it is again: Mini wankel
Old 04-14-2009 | 04:51 PM
  #41  
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From: PA/MD
here is my almost complete 13b. So far the only remaining tasks are to buy threaded rod for the long bolts, thread the eccentric shaft, bend the exhaust tubing, and order some new apex seal springs.

The engine does not have the water passages drilled yet because I am waiting to see if they are truly necessary for the model. I will run the engine while monitoring the temperature to decide. I have attached the front OS engine cover (bell housing location) to hopefully gain some cooling from the side mounted fins.

The side housings and eccentric shaft were also heated until they were glowing red and then oil quenched to help harden the surfaces and increase wear resistance. Note to self: do not grab the end of the pliers that were holding red hot metal with you bare hands!

Rear side housing ready to be cut to shape.


Just completed grinding the rear housing profile, the alignment rods need to be cut to length.


The engine completed to this point.



I hope to have a video of it running in the next few weeks. Somehow during the machining I managed to lose one of my fixed gears so I will have to order one of them as well, great waste of $40.
Old 04-15-2009 | 08:03 AM
  #42  
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What type of rpms are you estimating to spin? That tiny of a motor I am assuming the rpms would be north of 15k ? Also on your motor why does the housing have fins or spines on it? Is this for cooling, strength, stress or just by design ?

Such a cool project, keep up the good work.
Old 04-15-2009 | 12:25 PM
  #43  
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^thanks, I appreciate it.

A single OS engine is capable of 1.27hp @ 17k rpm's. I cannot give an exact answer on what my red line will be but, since I have increased the size of the engine the rpm's should be below 17k.

The fins on the housing are for cooling since it is made for rc planes it is air cooled from the propeller.

This project is to develop a prototype to test my machining and get experience with small scale rotaries. If this works I have already begun designs on a scale engine based exactly from the 13b (1/4 scale), and will include side and oil seals, water jacket, oil lubricated bearings, etc. This will not be made from any available engines, so all parts would be one off machined parts.
Old 04-15-2009 | 01:36 PM
  #44  
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Coolest project in the forum.
Old 04-15-2009 | 03:51 PM
  #45  
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Glad to see you are still working on this project and making progress! Can't wait to see the video of this little wonder engine running! If you ever get to the point of making a kit, let me know please!
Old 04-20-2009 | 07:24 PM
  #46  
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Sorry I'm late. This thread is awesome!
Old 04-20-2009 | 09:56 PM
  #47  
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im glad to see you got it up and put together.

get video of it running. very cool.
Old 04-20-2009 | 10:29 PM
  #48  
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I was going to do this a while back as well, until I figured out how big I'd have to make the car

pretty sweet progress, can't wait to see it done.
Old 04-20-2009 | 10:35 PM
  #49  
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I can't wait for a vid. This is the greatest project on the site that I've seen.
Old 04-20-2009 | 10:51 PM
  #50  
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From: PA/MD
thanks everyone!...I just got new seal springs, fuel line and fuel tank in today. Hope to have a video soon.


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