ADVrider

Go Back   ADVrider > Bikes > Old's Cool > 2 smokers
User Name
Password
Register Inmates Photos Site Rules Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
Old 08-01-2012, 08:53 AM   #31
anotherguy
Beastly Adventurer
 
anotherguy's Avatar
 
Joined: Jun 2009
Location: the hills
Oddometer: 5,915
Hubristic theory? Please. Setting the squish and flame front travel is elementary tuning. As is installing a good pipe (uhm FMF??).I am talking about simple effective tuning methods available to everyone.

Lack of education doesn't make what Emler and his contemporaries did less sophisticated. You must admit designing a good exhaust with pencil and paper does require some advanced knowledge of what goes on inside. And more than a little advanced mathematics.

I simply called out an obvious charlatan. Hubris has nothing to do with that.
__________________
A lie has no feet......it can't stand alone.............
Jason Newsted
anotherguy is offline   Reply With Quote
Old 08-01-2012, 10:11 AM   #32
supershaft
because I can
 
Joined: Sep 2010
Location: San Francisco Bay area
Oddometer: 8,145
Well, willus, Strong Bad and I could have a good discussion with this if it weren't for blow hards. Empirical data on the idiotnet? With pictures!
supershaft is offline   Reply With Quote
Old 08-01-2012, 10:37 AM   #33
Strong Bad
n00balicious
 
Strong Bad's Avatar
 
Joined: Oct 2007
Oddometer: 3,731
Quote:
Originally Posted by anotherguy View Post
Hubristic theory? Please. Setting the squish and flame front travel is elementary tuning. As is installing a good pipe (uhm FMF??).I am talking about simple effective tuning methods available to everyone.

Lack of education doesn't make what Emler and his contemporaries did less sophisticated. You must admit designing a good exhaust with pencil and paper does require some advanced knowledge of what goes on inside. And more than a little advanced mathematics.

I simply called out an obvious charlatan. Hubris has nothing to do with that.
Attempting to beat down a guy on the interweb in your manor is hubristic at best.

I'm telling the was it was with some of THE most successful 2 stroke tuners of the 70's & early 80's as seen from someone that was on the inside and intimately involved. Seat of the pants and hours and hours of trial and error is what happened. No pencils and no math, lots of; "what if we"? I bet none of them, even to this day, would know what a Reynolds Number represents.

Setting squish for some reason is a more recent concern, back in the 70's squish was only checked after a head was modified. Aftermarket heads were sold by the 1000's and the consumers were never told to (or how to) check the squish with the new head. I did hundreds of port jobs for EC Birt & Donnie in the 70's where the heads were not modified and squish was never addressed. That is simply the way it was AND it worked!
__________________
"I couldn't wait for success, so I went ahead without it."
Strong Bad is offline   Reply With Quote
Old 08-01-2012, 10:51 AM   #34
Icewalker
Conundrum
 
Icewalker's Avatar
 
Joined: Apr 2006
Location: New Hampshires Militant Hippy
Oddometer: 40,440
Interesting thread. I can't speak much for the bike world since almost all of my two stroke experience was in the world of European Karting. One thing I do remember though is that every once in a while someone would get a bone stock motor from the factory (usually a Parilla or DAP) and it would be as fast if not (in at least one case) faster than any of the ported motors out there.

I can't explain why - anyone want to take a stab at it?
__________________
Icewalker is offline   Reply With Quote
Old 08-01-2012, 01:40 PM   #35
Ever Onward
Time Killer
 
Ever Onward's Avatar
 
Joined: May 2011
Location: Past the point of no return
Oddometer: 613
Uhhhhh Ohhhhhh...............









Not only has the infamous Yamaha Power valve entered the equation........but, my TZR has shaved head which altered the squish, and cleaned up transfers.......I have no idea how it even runs now ?

If I polish all the ports to a mirror finish do I have a shot at a trophy on "bike night ?"





Ever Onward is offline   Reply With Quote
Old 08-01-2012, 05:16 PM   #36
willis 2000 OP
neo-quixote
 
Joined: Oct 2011
Location: idaho
Oddometer: 2,869
Quote:
Originally Posted by supershaft View Post
Well, willus, Strong Bad and I could have a good discussion with this if it weren't for blow hards. Empirical data on the idiotnet? With pictures!
I appreciate the differing points of view. Kinda like mechanics bench-racing. That squish angle/clearance/area was a part of the picture I was unaware of.
willis 2000 is offline   Reply With Quote
Old 08-01-2012, 06:08 PM   #37
anotherguy
Beastly Adventurer
 
anotherguy's Avatar
 
Joined: Jun 2009
Location: the hills
Oddometer: 5,915
I'm upset that someone doesn't like my manor. I always thought it was quite nice.






now that's hubris............

__________________
A lie has no feet......it can't stand alone.............
Jason Newsted
anotherguy is offline   Reply With Quote
Old 08-01-2012, 07:51 PM   #38
Abdelhub
Blanco Trasho
 
Abdelhub's Avatar
 
Joined: Nov 2007
Location: Snohomish County
Oddometer: 721
so is it ok to raise my exhaust port height by a mm???? time to get out my dremel.....

Mike
__________________
the most valuable bike i own hasn't run in 20 years...

http://www.youtube.com/abdelhub
Abdelhub is offline   Reply With Quote
Old 08-01-2012, 09:09 PM   #39
supershaft
because I can
 
Joined: Sep 2010
Location: San Francisco Bay area
Oddometer: 8,145
Quote:
Originally Posted by willis 2000 View Post
I appreciate the differing points of view. Kinda like mechanics bench-racing. That squish angle/clearance/area was a part of the picture I was unaware of.
Differing points of view are great. It's the character slamming/name calling that is nothing but a waste of time here on the idiotnet. That crap is better left for meetings in person IF it is to be brought up at all.

Compression/squish angle was always in the cards around my dad's shop. They experimented with it quite a bit if I remember right. When I was real little I think they even tried running alcohol but that was a little before my time I believe.
supershaft is offline   Reply With Quote
Old 08-01-2012, 09:11 PM   #40
supershaft
because I can
 
Joined: Sep 2010
Location: San Francisco Bay area
Oddometer: 8,145
Quote:
Originally Posted by Abdelhub View Post
so is it ok to raise my exhaust port height by a mm???? time to get out my dremel.....

Mike
Typically, raising the exhaust port is the last thing I would try. High rpm power? First you have to GET to high rpm!
supershaft is offline   Reply With Quote
Old 08-01-2012, 09:47 PM   #41
willis 2000 OP
neo-quixote
 
Joined: Oct 2011
Location: idaho
Oddometer: 2,869
Quote:
Originally Posted by Abdelhub View Post
so is it ok to raise my exhaust port height by a mm???? time to get out my dremel.....

Mike
Maybe, but not just yet. Leave your power tools alone.
You have some old Spanish stuff, and the casting work was inept. Look at the ports and you'll likely see some hasty factory attempt at curing the worst of it. Could you finish their work and make it better?
How does the base gasket fit the transfer ports? One mm there will make more difference than your exhaust port. How does that base gasket fit the crankcase?
willis 2000 is offline   Reply With Quote
Old 08-02-2012, 05:52 AM   #42
anotherguy
Beastly Adventurer
 
anotherguy's Avatar
 
Joined: Jun 2009
Location: the hills
Oddometer: 5,915
Quote:
Originally Posted by Abdelhub View Post
so is it ok to raise my exhaust port height by a mm???? time to get out my dremel.....

Mike
Before raising the exhaust I'd widen to the maximum allowable and profile for ring life. How many transfers in the cylinder we're talking about? Boost port? And the first question should have been what bike and what is your end goal?

If you really want to learn about porting Rick has a good article here.
__________________
A lie has no feet......it can't stand alone.............
Jason Newsted
anotherguy is offline   Reply With Quote
Old 08-03-2012, 12:29 AM   #43
Twin-shocker
Beastly Adventurer
 
Joined: Jan 2012
Oddometer: 1,673
Any sort of tuning work on any bike is relative to end use, and of course what bike its being carried out on. In most cases optimising the stock set up will be the sensible way to go, and while hacking away at ports may well mean gains in some areas in nearly all cases they will also mean losses in others.
Twin-shocker is offline   Reply With Quote
Old 08-03-2012, 12:50 AM   #44
willis 2000 OP
neo-quixote
 
Joined: Oct 2011
Location: idaho
Oddometer: 2,869
Quote:
Originally Posted by Twin-shocker View Post
Any sort of tuning work on any bike is relative to end use, and of course what bike its being carried out on. In most cases optimising the stock set up will be the sensible way to go, and while hacking away at ports may well mean gains in some areas in nearly all cases they will also mean losses in others.
Not necessarily true. My advice is balance left-to-right first. It requires caps, DO NOT touch the cylinder openings. Get the transfer ports working correctly first. Read a bit on fluid dynamics, ok, here it gets weird, but think of runny jell-o running through your ports. A mismatch or a sharp edge will cause a turbulent flow, The polish is inconsequential as the boundary layer is at least .010". On these old air-cooled bikes, first concentrate on getting the transfer ports evenly matched, use your fingers as gauges and a base gasket as measurement. Y'all might be surprised how many of these old motors need the crankcase portion of the transfer ports modified to get even flow.
willis 2000 is offline   Reply With Quote
Old 08-03-2012, 06:47 AM   #45
Twin-shocker
Beastly Adventurer
 
Joined: Jan 2012
Oddometer: 1,673
An awful lot of people seem to think that things such as OE squish clearance of 2mm, and less than ideal exhaust and induction systems make no difference at all. Contrary to popular belief though, without sorting out these basic areas first, any other work carried out wont work anywhere near as well as with the basics done first, and is a bit like fitting a 40mm carb to a bog stock 125cc scooter.
Twin-shocker is offline   Reply With Quote
Reply

Share

Thread Tools Search this Thread
Search this Thread:

.
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


Times are GMT -7.   It's 12:09 AM.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright ADVrider 2011-2014