Go Back  R/C Tech Forums > General Forums > Nitro Off-Road
Piston c-clip position??? >

Piston c-clip position???

Community
Wiki Posts
Search

Piston c-clip position???

Thread Tools
 
Search this Thread
 
Old 10-21-2009, 06:33 PM
  #1  
Tech Adept
Thread Starter
iTrader: (-1)
 
Join Date: Dec 2007
Posts: 155
Questions?? Piston c-clip position???

What's the better c-clip position to place when we change connecting rod??

I have recieve my Jammin 28 as in #1 pics, but want to know you, how you install it, because i think that the position of the clip is important.

pic #1


pic #2


pic #3
dakamat is offline  
Old 10-21-2009, 06:51 PM
  #2  
Tech Elite
iTrader: (25)
 
Racecrafter's Avatar
 
Join Date: Apr 2007
Location: RC Mecca
Posts: 4,140
Trader Rating: 25 (96%+)
Default

It doesn't matter as long as it is in the grove securely.
Racecrafter is offline  
Old 10-21-2009, 07:02 PM
  #3  
Tech Master
iTrader: (12)
 
motomatt's Avatar
 
Join Date: Mar 2007
Location: WI
Posts: 1,283
Trader Rating: 12 (100%+)
Default

It DOES matter.
when that engine is going 40,000 rpm, that little clip is: moving in one direction, stopping almost instantly, then reversing direction 80,000 times per minute. That's a lot of inertia. It's own mass can cause the clip ends to "close towards each other" more freely if the gap is at the 3 or 9 o'clock position. I ALWAYS assemble with the gap at the bottom or top. ( 6 or 9 o'clock)
motomatt is offline  
Old 10-21-2009, 07:17 PM
  #4  
Tech Elite
iTrader: (25)
 
Racecrafter's Avatar
 
Join Date: Apr 2007
Location: RC Mecca
Posts: 4,140
Trader Rating: 25 (96%+)
Default

Originally Posted by motomatt
It DOES matter.
when that engine is going 40,000 rpm, that little clip is: moving in one direction, stopping almost instantly, then reversing direction 80,000 times per minute. That's a lot of inertia. It's own mass can cause the clip ends to "close towards each other" more freely if the gap is at the 3 or 9 o'clock position. I ALWAYS assemble with the gap at the bottom or top. ( 6 or 9 o'clock)
You're not serious are you?

The tension of the clip will out hold the inertia of it's own weight.
Racecrafter is offline  
Old 10-21-2009, 07:35 PM
  #5  
Tech Master
iTrader: (12)
 
motomatt's Avatar
 
Join Date: Mar 2007
Location: WI
Posts: 1,283
Trader Rating: 12 (100%+)
Default

Originally Posted by Racecrafter
You're not serious are you?
Very.
The stroke of a .21 engine is approx. 17mm. This means the piston would travel 17mm 40,000 times per minute/666 times per second/ for a final value of.........11,333 mm traveled per second. "Uncle Albert's" theory of relativity states that E= MC squared. Energy equals mass times the square of the velocity. Inversely, as speed doubles the energy of the mass (insert the word circlip) squares.
motomatt is offline  
Old 10-21-2009, 08:00 PM
  #6  
Tech Addict
iTrader: (36)
 
Join Date: Sep 2006
Location: Lynn Haven Florida
Posts: 512
Trader Rating: 36 (100%+)
Default

Uncle Albert's theory is not what's at play here. The equation you cited indicates how much energy would result from the complete conversion of the mass of the clip into energy, not its inertia nor even its momentum (which is what is really the force involved). The momentum (momentum=mass x velocity), the decceleration, and the spring constant of the clip would be used to determine if the clip would deform enough to dislodge from the groove.
rstnboy is offline  
Old 10-21-2009, 08:09 PM
  #7  
Tech Elite
iTrader: (1)
 
imaxx21's Avatar
 
Join Date: Nov 2007
Location: LA
Posts: 2,753
Trader Rating: 1 (100%+)
Default

It doesn't matter as long as it is in the grove securely.
imaxx21 is offline  
Old 10-21-2009, 08:12 PM
  #8  
Tech Master
 
Join Date: Dec 2008
Location: So Cal
Posts: 1,696
Default

Ok moving away from theory and to actual practice.
I slap the clips in and run the motor till the rod breaks in half

Seriously though, it does not matter where the clip is pointing.

Next thing we'll be debating is if having your motor tilted will increase wear on the low side of the engine
Alan D. is offline  
Old 10-21-2009, 08:17 PM
  #9  
Tech Addict
iTrader: (36)
 
Join Date: Sep 2006
Location: Lynn Haven Florida
Posts: 512
Trader Rating: 36 (100%+)
Default

Originally Posted by Alan D.
Next thing we'll be debating is if having your motor tilted will increase wear on the low side of the engine
You mean it doesn't!!! Now I find out after all that time I spent shimming my engine exactly perpendicular to the chassis
rstnboy is offline  
Old 10-21-2009, 08:19 PM
  #10  
Tech Master
 
Join Date: Dec 2008
Location: So Cal
Posts: 1,696
Default


Those hyper 9's must go through engines like crazy.
Alan D. is offline  
Old 10-21-2009, 08:34 PM
  #11  
Tech Addict
 
Join Date: Oct 2008
Posts: 577
Default

I can tell you on a two stroke, chaisaw, weed eater,back pack blower, snowmobile , jetski, dirtbike, boat motor, four stroke engines that turn upwards of 10k rpm it is absolutely critical.Now in nitro if it doesn't matter.... i will make sure the opening of the clip is at ether 12 o clock or 6 o clock. If you put the opening at 3 or 9 it can deform.physics change at the speed of light/nitro. FACT
Joey Platinum is offline  
Old 10-21-2009, 08:38 PM
  #12  
Tech Lord
iTrader: (24)
 
wingracer's Avatar
 
Join Date: Nov 2007
Posts: 13,737
Trader Rating: 24 (100%+)
Default

In practice, it doesn't seem to matter since most motors are not going to last long enough to matter.

However, if you want it perfect, the little tab should be straight up and down (vertical). Top or bottom doesn't matter.

The reason: if the tab is horizontal it will bend up and down slightly with every stroke. This constant flexing could cause the metal to fatigue and the tab to break off, doing serious engine damage. I have actually seen this happen on motorcycle motors with LOTS of time on them but like I said, ours don't seem to last long enough to fatigue them.
wingracer is offline  
Old 10-22-2009, 08:53 AM
  #13  
Tech Elite
iTrader: (25)
 
Racecrafter's Avatar
 
Join Date: Apr 2007
Location: RC Mecca
Posts: 4,140
Trader Rating: 25 (96%+)
Default

Originally Posted by rstnboy
Uncle Albert's theory is not what's at play here. The equation you cited indicates how much energy would result from the complete conversion of the mass of the clip into energy, not its inertia nor even its momentum (which is what is really the force involved). The momentum (momentum=mass x velocity), the decceleration, and the spring constant of the clip would be used to determine if the clip would deform enough to dislodge from the groove.
Thank you for explaining that.

Otherwise we would have to have to tried to figure out E=MC2 vs. kg·m/s2
Racecrafter is offline  
Old 10-22-2009, 09:07 AM
  #14  
Tech Master
 
alexrckid's Avatar
 
Join Date: Jul 2006
Location: south carolina
Posts: 1,555
Default hey dakamat...question...

sorta unrealted question.....i've got two jammin .28's. had to break both down for rebuilds. found the CON ROD on one of them with the bushing OILING HOLE facing the front of the engine(typical) and the other one with the OILING HOLE facing the rear(??...not exactly typical). ran this finding by the NITROHOUSE guys(picco knowledge base). they told me that the .28's have the con rod oiling hole facing the rear of the engine where it can pick up more lube(somehow)...??? sounded kinda wacky to me.....so.......which way the the OILING HOLE facing on your .28...??
alexrckid is offline  
Old 10-22-2009, 09:44 AM
  #15  
Tech Elite
 
token's Avatar
 
Join Date: Mar 2009
Location: Aurora, Colorado
Posts: 4,644
Default

I REALLY dont think it matters - but out of the piston and rods i have seen they are all like PIC 2/3
token is offline  


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.