General Rotary Tech Support Use this forum for tech questions not specific to a certain model year
Sponsored by:
Sponsored by: CARiD

General rotary question

Thread Tools
 
Search this Thread
 
Old Apr 19, 2004 | 01:40 AM
  #1  
Jinx099's Avatar
Thread Starter
Full Member
Tenured Member 05 Years
 
Joined: Dec 2002
Posts: 225
Likes: 0
From: Aurora, CO
Question General rotary question

Not sure when I thought of this, but how exactly does the rotary engine keep it's compression when the apex seals move over the spark plug gaps?
Reply
Old Apr 20, 2004 | 01:16 AM
  #2  
rxtasy3's Avatar
Moderator
Tenured Member: 20 Years
iTrader: (2)
 
Joined: Jun 2002
Posts: 9,579
Likes: 290
From: Spartanburg, SC
same as a pist on engine does, the plug acts as a plug in the hole.
Reply
Old Apr 20, 2004 | 12:06 PM
  #3  
Jinx099's Avatar
Thread Starter
Full Member
Tenured Member 05 Years
 
Joined: Dec 2002
Posts: 225
Likes: 0
From: Aurora, CO
but the plugs are not completely flush with the rotor housing.
Reply
Old Apr 20, 2004 | 12:31 PM
  #4  
Railgun's Avatar
I won't let go
Veteran: Marine Corp
Tenured Member: 20 Years
Liked
Loved
 
Joined: Aug 2002
Posts: 3,871
Likes: 23
From: Chi -> Maidstone
So you loose what, about 3cc of volume if not less? It's not that big of a hole thus it's not a concern where compression is concerned.
Reply
Old Apr 20, 2004 | 01:57 PM
  #5  
Jinx099's Avatar
Thread Starter
Full Member
Tenured Member 05 Years
 
Joined: Dec 2002
Posts: 225
Likes: 0
From: Aurora, CO
but if the apex seal stops (or just goes slow) in the middle of this gap, it will lose all it's compression to the other side of the seal. I'm assuming this is less of an issue with higher RPMs then?
Reply
Old Apr 20, 2004 | 04:10 PM
  #6  
rototiller1's Avatar
Inspector, Falcon Jet
Tenured Member 05 Years
 
Joined: Mar 2003
Posts: 430
Likes: 0
From: Little Rock
You should think that thru again
Reply
Old Apr 20, 2004 | 04:18 PM
  #7  
Jinx099's Avatar
Thread Starter
Full Member
Tenured Member 05 Years
 
Joined: Dec 2002
Posts: 225
Likes: 0
From: Aurora, CO
maybe it would help me if someone posted a pic of a bare housing with a plug in it.
Reply
Old Apr 20, 2004 | 05:10 PM
  #8  
mgoddard1's Avatar
I luv my carbon footprint
Tenured Member 15 Years
 
Joined: Mar 2002
Posts: 452
Likes: 0
From: Indianapolis
The spark plug is much wider than the apex seal so if the seal stops over the plug you can lose compression. However, the period when the seal is over the plugs is probably less than a millisecond so there is virtually no time to lose compression through a very small gap.
Reply
Old Apr 20, 2004 | 05:54 PM
  #9  
Jinx099's Avatar
Thread Starter
Full Member
Tenured Member 05 Years
 
Joined: Dec 2002
Posts: 225
Likes: 0
From: Aurora, CO
Originally posted by mgoddard1
The spark plug is much wider than the apex seal so if the seal stops over the plug you can lose compression. However, the period when the seal is over the plugs is probably less than a millisecond so there is virtually no time to lose compression through a very small gap.
Thanks for the explanation.
Reply
Old Apr 20, 2004 | 08:25 PM
  #10  
rototiller1's Avatar
Inspector, Falcon Jet
Tenured Member 05 Years
 
Joined: Mar 2003
Posts: 430
Likes: 0
From: Little Rock
The seal does not simply rotate past the plugs. Its a eliptical rotation. Up and Down while going round and round. Also the volume of the spark plug holes is there during the intake cycle, so volume is not lost on the compression cycle

http://travel.howstuffworks.com/rotary-engine.htm

Last edited by rototiller1; Apr 20, 2004 at 08:30 PM.
Reply
Old Apr 20, 2004 | 09:10 PM
  #11  
MikeC's Avatar
Senior Member
Tenured Member: 20 Years
Liked
 
Joined: Sep 2002
Posts: 314
Likes: 0
From: Australia
Re: General rotary question

Originally posted by Jinx099
Not sure when I thought of this, but how exactly does the rotary engine keep it's compression when the apex seals move over the spark plug gaps?
This is a good question. The answer is yes, some compression will be lost but you have to look at the point the rotor is at when the apex seal passes over the spark plug. When it passes over the leading plug pressure on either side of the seal will be low, but when it passes over the trailing the pressure will be high. This is why the trailing plug has a much smaller hole.
Reply
Old Apr 20, 2004 | 09:12 PM
  #12  
MikeC's Avatar
Senior Member
Tenured Member: 20 Years
Liked
 
Joined: Sep 2002
Posts: 314
Likes: 0
From: Australia
Re: General rotary question

oops, triple post, server ain't working too well today, it gave me three errors in a row but posted the message each time.

Last edited by MikeC; Apr 20, 2004 at 09:39 PM.
Reply
Old Apr 20, 2004 | 09:19 PM
  #13  
MikeC's Avatar
Senior Member
Tenured Member: 20 Years
Liked
 
Joined: Sep 2002
Posts: 314
Likes: 0
From: Australia
Re: General rotary question

oops, multipost....

Last edited by MikeC; Apr 20, 2004 at 09:34 PM.
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
The1Sun
New Member RX-7 Technical
9
Mar 18, 2018 11:08 PM
Seaweed
Introduce yourself
0
Aug 16, 2015 11:46 AM
Professorpeanutrx7
New Member RX-7 Technical
5
Aug 15, 2015 01:38 PM




All times are GMT -5. The time now is 11:53 PM.