Kawi2strokes.com Forum

Enthusiasts from around the world dedicated to the preservation and ritual flogging of the infamous Kawasaki 2-stroke Triples
It is currently Wed Jul 16, 2025 8:41 am

Board index » Our legendary Kawasaki Triples » General Chat

All times are UTC - 5 hours




Post new topic Reply to topic  Page 3 of 3
  [ 29 posts ]  Go to page Previous  1, 2, 3
  Print view Previous topic | Next topic 
Author Message
Jim
PostPosted: Sun Jan 22, 2012 4:47 pm 
User avatar

Joined: Wed Jun 08, 2011 11:34 pm
Posts: 10016
Location: North Central NC
wejext wrote:
In general yes - but in this case: nope! General statements are risky if the work which has been done is unknown.

I think you may have misunderstood Looney Cylinders' post.

_________________
If it surges, that's normal, upshift.
Top
 Profile  
 
wejext
PostPosted: Sun Jan 22, 2012 5:41 pm 

Joined: Tue Aug 02, 2011 11:21 am
Posts: 27
If so - please exlain what's wrong. The study was done for motorcycle applications as well - of course not for race bikes, but for road bikes.
Top
 Profile  
 
Jim
PostPosted: Sun Jan 22, 2012 5:45 pm 
User avatar

Joined: Wed Jun 08, 2011 11:34 pm
Posts: 10016
Location: North Central NC
I don't know that anything is wrong. LC was saying that the modified port shape probably doesn't hurt power when used with an engine that does not have an expansion chamber exhaust system, but that for engines that do, like our triples, softening the exhaust pressure pulse is likely to hurt performance, since the returning waves will be proportionally softened. Your chart doesn't seem to have any information about power output for the various port shapes, but as LC said, it's believable that it didn't suffer much with the untuned exhaust of a chainsaw.

I think your chart is interesting, and may help explain why newer chainsaws are much quieter than the ones I remember from the 1960s.

_________________
If it surges, that's normal, upshift.


Last edited by Jim on Sun Jan 22, 2012 5:50 pm, edited 1 time in total.

Top
 Profile  
 
Looney Cylinders
PostPosted: Sun Jan 22, 2012 5:48 pm 

Joined: Thu Jun 09, 2011 2:00 am
Posts: 1010
Location: Southern Ontario, Canada
Jim wrote:
I don't know that anything is wrong. LC was saying that the modified port shape probably doesn't hurt power when used with an engine that does not have an expansion chamber exhaust system, but that for engines that do, like our triples, softening the exhaust pressure pulse is likely to hurt performance, since the returning waves will be proportionally softened. Your chart doesn't seem to have any information about power output for the various port shapes.


That's exactly what I was saying. :?

J
Top
 Profile  
 
JRD
PostPosted: Sun Jan 22, 2012 5:56 pm 
User avatar

Joined: Thu Jun 09, 2011 6:26 pm
Posts: 901
Location: Zionsville,PA
A quick lap thru photobucket found these

Image

Image

Image

Image

Image

and finally .....


Image
Top
 Profile  
 
oxford
PostPosted: Sun Jan 22, 2012 7:30 pm 
User avatar

Joined: Thu Jun 09, 2011 8:44 am
Posts: 1159
Location: Bangor, PA
Ja-Moo wrote:
have a much louder "cackle"


So John, does one tune a motor for this so called cackle :shifty:
Top
 Profile  
 
Ja-Moo
PostPosted: Sun Jan 22, 2012 7:39 pm 
Site Admin
User avatar

Joined: Tue Jun 07, 2011 6:37 am
Posts: 10460
Location: Rio Rancho, New Mexico
oxford wrote:
Ja-Moo wrote:
have a much louder "cackle"


So John, does one tune a motor for this so called cackle :shifty:


Not at all, just a by-product of harder porting and squarer exhaust ports give a louder cackle. You can still get the port angles, size and blowdown wrong and not make power, but it will be cackly..............

_________________
Twist the throttle, tilt the horizon, and have a great time. What triples are all about...........
Top
 Profile  
 
oxford
PostPosted: Sun Jan 22, 2012 7:43 pm 
User avatar

Joined: Thu Jun 09, 2011 8:44 am
Posts: 1159
Location: Bangor, PA
Ja-Moo wrote:
oxford wrote:
Ja-Moo wrote:
have a much louder "cackle"


So John, does one tune a motor for this so called cackle :shifty:


Not at all, just a by-product of harder porting and squarer exhaust ports give a louder cackle. You can still get the port angles, size and blowdown wrong and not make power, but it will be cackly..............


That went over your head, I do frequent 2SW, I thought you would get the reference. :lol:
Top
 Profile  
 
Ja-Moo
PostPosted: Sun Jan 22, 2012 10:02 pm 
Site Admin
User avatar

Joined: Tue Jun 07, 2011 6:37 am
Posts: 10460
Location: Rio Rancho, New Mexico
oxford wrote:
Ja-Moo wrote:
oxford wrote:
Ja-Moo wrote:
have a much louder "cackle"


So John, does one tune a motor for this so called cackle :shifty:


Not at all, just a by-product of harder porting and squarer exhaust ports give a louder cackle. You can still get the port angles, size and blowdown wrong and not make power, but it will be cackly..............


That went over your head, I do frequent 2SW, I thought you would get the reference. :lol:



AH the "kevin" factor......... :banghead :wtf: :roll: :banghead

_________________
Twist the throttle, tilt the horizon, and have a great time. What triples are all about...........
Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  Page 3 of 3
  [ 29 posts ]  Go to page Previous  1, 2, 3

Board index » Our legendary Kawasaki Triples » General Chat

All times are UTC - 5 hours


Who is online

Users browsing this forum: Bing [Bot]

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  
Powered by phpBB® Forum Software © phpBB Group