All Things Moto! Dirtbike Forums

Go Back   All Things Moto! Dirtbike Forums > Dirt Bike Knowledge Base and Build Threads > 2-Stroke Dirt Bike Knowledge Base

Reply
 
LinkBack Thread Tools
  #31  
Old 12-30-2005, 01:00 PM
ATM! Addict
 
Join Date: Oct 2003
Last Online: 04-14-2014 09:07 AM
Location: alaska
Posts: 10,344
Default Re: Calculating Head Squish Measurements - (REP)

     

I wouldnt get too warm and fuzzy about that original Genesis design. I am not sure that Yamaha would have had to patent the original one to keep it from being copied. There was a lot about the FZ750 to make it desireable, but from what I keep calling the garage tuner or builders standpoint, there was a good reason that other designs were more desireable. In a nutshell, any engine that required you to run advances as high as mid 40's (ignition advance in degrees before TDC) was not a particularly good design. Compressing gasses that are expanding is not considered desireable (a horrible waste of energy in my opinion). Yamaha changed that, kept the amount of valves and kept the name. But that original chamber design is probably safe for the ages.

With all that you know about overlap and how compression ratios are figured, I guess you were just testing us with that question about 2 strokes and 4 strokes weren't you?
Reply With Quote
  #32  
Old 01-25-2006, 02:14 PM
2kHondaCR500R's Avatar
Pro Class
 
Join Date: Mar 2004
Last Online: 07-15-2018 03:11 AM
Location: Old Hickory, TN
Posts: 1,503
Default Re: Calculating Head Squish Measurements - (REP)

Wow! Great info guys!
Reply With Quote
  #33  
Old 01-25-2006, 09:25 PM
Tdub's Avatar
ATM! Pro Class
 
Join Date: Dec 2002
Last Online: 01-22-2016 10:26 PM
Location: The OWB, Kentucky
Posts: 3,026
Default Re: Calculating Head Squish Measurements - (REP)

As far as the Genesis engine design, ever wonder why Rossi's MotoGP Yamaha only has FOUR valves per cylinder?? One way to make a 5 valve YZF achieve the same HP as a 4 valve CRF? Make the YZF a 4 valve head! LOL Tdub
Reply With Quote
  #34  
Old 01-27-2006, 12:02 PM
ATM! Addict
 
Join Date: Oct 2003
Last Online: 04-14-2014 09:07 AM
Location: alaska
Posts: 10,344
Default Re: Calculating Head Squish Measurements - (REP)

So did you get that 4 valve working on the blue rig? I noticed last year that Yam's new 4 valved 3 cylinder snowmachine engine is called,,,,(what else) a "Genisis". Interesting chamber on it and it works well.
Reply With Quote
  #35  
Old 06-01-2008, 01:33 PM
Welcome To ATM
 
Join Date: Jun 2008
Last Online: 05-25-2009 01:08 PM
Location: Idaho
Posts: 4
Default Re: Calculating Head Squish Measurements - (REP)

I have some tech articles on my website that discuss these issues .

They are located at RK Tek 2-Stroke Heads: Technical Articles if you wish to have a look

Kelsey

Last edited by Kels; 06-06-2008 at 03:46 PM. Reason: Spelling
Reply With Quote
  #36  
Old 06-06-2008, 11:53 AM
Intermediate Class
 
Join Date: Jun 2005
Last Online: 05-29-2012 01:15 PM
Location: Georgia
Posts: 195
Default Re: Calculating Head Squish Measurements - (REP)

Welcome to ATM.

You do have some great articles on your sight. Thanks for putting that out their for people. It would benefit most people to go read them.

If I may offer some feedback to Kelsey... I couldn't get past some of the terminology discrepancies. Small albeit, but significant enough to cause confusion in someone who is learning. i.e. One of your articlea is spot on about the importance of measuring and knowing the relationship between the top of the piston at TDC and the top of the cylinder. But your article refers to this as "Piston Deck Height" which as your article moves on, abbreviates to "Deck Height". This relationship of the Piston to the Deck is called "Piston Deck Clearance" or "Deck Clearance". But describing this incorrectly as "Deck Height" will certainly lead to confusion for a few people as they try to learn more about building engines.

"Deck Height" is the distance from the centerline of the crank to the top of the cylinder. "Deck clearance" is Deck Height minus Stroke + Rod length + piston compression height +/- variances = where the top edge of teh piston will stop at the top of the stroke.

To Kelsey... Don't mean to nitpick, it's just a peeve of mine. I welcome them back also.

To everyone else go read Kelsey's articles

Ride safe

Ian

Last edited by E-man811; 06-06-2008 at 02:16 PM. Reason: added sig / name
Reply With Quote
  #37  
Old 06-06-2008, 04:01 PM
Welcome To ATM
 
Join Date: Jun 2008
Last Online: 05-25-2009 01:08 PM
Location: Idaho
Posts: 4
Default Re: Calculating Head Squish Measurements - (REP)

I appreciate the feedback..

You are correct.. By me abbreviating "Piston Deck Height" to "Deck Height" .. I can see how it could take on a diffrent meaning to those 4 stroke engine builders..

I do believe that piston deck height is a clear and correct term and is also known as piston deck clearance.. While deck height by itself could relate to block deck height..

Thanks for pointing that out.. I will modify my article..

Kelsey
Reply With Quote
  #38  
Old 02-25-2011, 05:14 PM
hellhound's Avatar
Novice Class
 
Join Date: Jan 2011
Last Online: 07-31-2014 12:03 AM
Location: michigan
Posts: 95
Default

wow,thats awesome information thankyou so much for takeing the time to write that.i wish i could just bring lots of my stuff in but i wont get into all the reasons why i dont.i really think you and doggers posts are the best i have read so far.iam still not done yet lots to go.
Reply With Quote
Reply

  All Things Moto! Dirtbike Forums > Dirt Bike Knowledge Base and Build Threads > 2-Stroke Dirt Bike Knowledge Base


Thread Tools


Similar Threads for: Calculating Head Squish Measurements - (REP)
Thread Thread Starter Forum Replies Last Post
gytr head vr. stock head pipe lilrig2 ATV/UTV - Yamaha 1 04-12-2009 03:12 PM
uneven squish band a problem? AV8R 2-Stroke Dirt Bikes - Yamaha 1 02-15-2008 10:58 AM
Pitting in Squish Band dhighlan 2-Stroke Dirt Bike Forums 9 08-29-2007 12:55 PM
Kawasaki KX65 Measurements...hmm... domcole_uk General Discussion 1 07-26-2006 01:25 PM
phat head racing cylinder head MXer-YoHon 2-Stroke Dirt Bike Forums 25 12-15-2004 03:05 PM


All times are GMT -6. The time now is 08:08 PM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright ©2002-2019, JDub Consulting, Inc. All Right Reserved.