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

why do rotaries spit so much flames?

Thread Tools
 
Search this Thread
 
Old 12-20-06, 09:26 PM
  #1  
Junior Member
Thread Starter
 
sunny turbo's Avatar
 
Join Date: Dec 2006
Location: ny
Posts: 13
Likes: 0
Received 0 Likes on 0 Posts
why do rotaries spit so much flames?

i know the rotary engines are notorious for spitting out flames. why is this so? does the air fuel mixture have anything to do with it or is it just the overlap that occurs?
Old 12-20-06, 09:50 PM
  #2  
Rotary Freak

iTrader: (2)
 
JWteknix's Avatar
 
Join Date: Mar 2006
Location: Wayne NJ
Posts: 2,508
Likes: 0
Received 0 Likes on 0 Posts
they run rich
Old 12-27-06, 08:10 PM
  #3  
Boost in..Apex seals out.

 
adrock3217's Avatar
 
Join Date: Nov 2003
Location: Maryland, 21794
Posts: 1,931
Likes: 0
Received 0 Likes on 0 Posts
Uh yeah, just because a car runs rich doesn't mean its going to spit flames. That just means its going to smell like gas, and burn eyes.

The rotary engine, by design, is imperfect. The combustion chamber is long and narrow, HORRIBLE if you are trying to get a complete burn.
Old 12-27-06, 08:20 PM
  #4  
Rotor Power Rules

iTrader: (5)
 
Bruceman's Avatar
 
Join Date: Jul 2001
Location: Rochester Hills, MI
Posts: 525
Received 2 Likes on 1 Post
I think it is because of the very high exhaust gas temperature which makes the exhaust sytem hot enough to ignite any raw/unburnt fuel that leaves the exhaust port.
Old 12-27-06, 08:33 PM
  #5  
5 2 many projects

 
HRforsale's Avatar
 
Join Date: Nov 2006
Location: Jackson, TN
Posts: 88
Likes: 0
Received 0 Likes on 0 Posts
Possibly that and they are inefficent in burning all the a/f mixture.
Old 12-27-06, 08:37 PM
  #6  
I F****D a mermaiiiid

 
Join Date: Dec 2001
Location: Jacksonville, FL
Posts: 208
Likes: 0
Received 0 Likes on 0 Posts
it has to do with a number of factors. The incomplete burn on most turbo rotaries, the tuning, the temperature of the exhaust, the sometimes retarded amount of overlap, the wasted spark ignition... I think a lot of it starts with the factory engine management. The factory computers don't cut the fuel on decel from what i remember, they just run it very lean for better throttle transition. this typically causes a pooling in the exhaust pipes where the heat is generally high enough light it off. now... we all know that we need 3 parts for compbustion - ignition, fuel, and AIR - you see the flames when that cocktail reaches the air.

Ray
Old 12-29-06, 09:19 AM
  #7  
Full Member

 
jectrx7's Avatar
 
Join Date: May 2005
Location: washington
Posts: 185
Likes: 0
Received 0 Likes on 0 Posts
i remember reading that a large part of why this happens is due to oil being present in the combustion chamber to lubricate the apex seals. don't know for sure though its just something i remember reading on the forum.
Old 12-29-06, 03:46 PM
  #8  
BMW Tech

 
White94RX's Avatar
 
Join Date: Mar 2002
Location: Auburn, Alabama
Posts: 845
Likes: 0
Received 0 Likes on 0 Posts
what's more flammable, oil or gas?
Old 12-29-06, 05:26 PM
  #9  
Rotary Enthusiast

 
telum01's Avatar
 
Join Date: Apr 2006
Location: Grovetown, Ga
Posts: 849
Likes: 0
Received 0 Likes on 0 Posts
maybe it's a combination of everything you guys have mentioned.......
Old 01-11-07, 08:52 PM
  #10  
The Sleeve

 
TheWoganSleeve's Avatar
 
Join Date: Apr 2006
Location: merseyside
Posts: 268
Likes: 0
Received 0 Likes on 0 Posts
maybe its magic
Old 01-12-07, 04:12 PM
  #11  
2nd Gen. Enthusiast

 
Rotary_Rocket_87's Avatar
 
Join Date: Feb 2006
Location: New Hampshire
Posts: 388
Likes: 0
Received 0 Likes on 0 Posts
It has to do with just about everything that was mentioned already.

Most RXs that throw flames have a free flowing exhaust with no cats. This causes the unburnt fuel (from running rich) and noctious (sp?) gasses from combustion (that would normally get burned by the cat) to combust at the tailpipe. This happens because inside the ehaust there is no oxygen, and you can't have a flame without some oxygen present. When this coctail of unburnt gasses hits the atmoshpere outside the exhaust...bam... a flame.
Old 01-13-07, 12:55 AM
  #12  
brap brap brap

 
forced inducted fd dude's Avatar
 
Join Date: May 2005
Location: miami
Posts: 669
Likes: 0
Received 0 Likes on 0 Posts
ay it keeps tailgaters away and sure makes a hell of a scare when poping flames flying at 100mph past a bus stop full of ppl lol
Old 01-13-07, 03:36 AM
  #13  
Senior Member

iTrader: (5)
 
streetRx7's Avatar
 
Join Date: Feb 2004
Location: nj & st.croix
Posts: 495
Likes: 0
Received 0 Likes on 0 Posts
lol +1 funny^^^^^^^
Old 01-18-07, 06:59 AM
  #14  
Senior Member

 
gainer_reniag's Avatar
 
Join Date: Feb 2006
Location: Gulfport, MS
Posts: 432
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by TheWoganSleeve
maybe its magic
Thats so funny
Old 01-18-07, 07:14 AM
  #15  
Iam LoneCorp Hear Me Roar
 
LoneCorp's Avatar
 
Join Date: Dec 2007
Location: New York
Posts: 464
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by TheWoganSleeve
maybe its magic
Harry potter get outta my exhaust system silly goose.
Old 01-18-07, 07:35 AM
  #16  
AUTOBAHN!!!

 
AF_H1VLTG3's Avatar
 
Join Date: May 2006
Location: Sherman, Texas USA
Posts: 455
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by Rotary_Rocket_87
It has to do with just about everything that was mentioned already.

Most RXs that throw flames have a free flowing exhaust with no cats. This causes the unburnt fuel (from running rich) and noctious (sp?) gasses from combustion (that would normally get burned by the cat) to combust at the tailpipe. This happens because inside the ehaust there is no oxygen, and you can't have a flame without some oxygen present. When this coctail of unburnt gasses hits the atmoshpere outside the exhaust...bam... a flame.
Agreed.....
Cuz I spit hot fire....
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
datfast1
Old School and Other Rotary
18
06-20-19 10:53 PM
Under PSI
3rd Generation Specific (1993-2002)
19
09-23-15 11:47 PM
datfast1
West RX-7 Forum
3
09-14-15 06:58 PM
andyvideopro
SE RX-7 Forum
0
09-05-15 06:56 PM
Murilli
Midwest RX-7 Forum
0
09-03-15 09:10 AM



Quick Reply: why do rotaries spit so much flames?



All times are GMT -5. The time now is 02:29 AM.