ADVrider

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

Reply
 
Thread Tools Search this Thread Display Modes
Old 01-04-2011, 03:59 PM   #16
techforlife
CDI REPAIR
 
techforlife's Avatar
 
Joined: Sep 2008
Location: Moncton,New Brunswick
Oddometer: 4,239
Quote:
Originally Posted by cyclewizard View Post
Hi brian, are you having problems with your HC piston spark knocking?
How about power, did it help you there or couldn't you tell the difference?
Have you thought about putting the stock one back in?
No.....i put in a XR600R JE 10.5-1 piston........so i`m only at about 9.3-1 or so...so no spark knock here..........not alot of power increase,but there is more low end torque...and no the JE piston is staying in..

I was just warning the OP that it can be a problem,having spark knock...

B
__________________
01 XR650L,102mm JE 11.25:1..NX650 second gear,FMX650 fifth gear,ported CW head,KW valve train,MegaCycle 173X25.FCR MX pumper.42/158 NVCT needle.Cycra probend CRM,Scott`s sharkfin,Xr`s Only casesaver.FMF "Q2",Sutton Oil Cooler,Clarke 4.0,Red XR`s Only skidplate,Doubletake mirrors,Manracks Rotopax rack..one Minature Schnauzer
techforlife is offline   Reply With Quote
Old 01-04-2011, 04:08 PM   #17
techforlife
CDI REPAIR
 
techforlife's Avatar
 
Joined: Sep 2008
Location: Moncton,New Brunswick
Oddometer: 4,239
Quote:
Originally Posted by Dr LC8 View Post
...so all in all...

Better carburettor (xr650r can do the job), nx 2nd gear and I'll get the most out of it?
I might go with it.
Is there any chance to increase the compression by lowering the head?

Your help guys is first class

Nic

P.S. All I would like is to get as much as an XR600r...

Better carb will help,,the XR650R is a decent carb,,but better benifits come from a pumper carb........

I wouldn`t lower/cut the head to get more power.....


If i was going to go rebuild my engine again...i`d get a larger piston...but keep the compression ratio below the 10.5-1.........105 or 106mm ...the larger bore will give more power and no spark knock issues...

Cyclewizard is the guy to ask on that......he may suggest a higher compression ratio than i would,,,,he`s got more experience ..


The NX650 2nd gear is really nice for wheelies i can tell you,,and in tigh woods or sand really makes a difference getting the bike moving..


oh........ consider this too though.......the XR600R had more power than the XR650L........but i think the most difference is in the internal transmission gearing and the final drive (sprockets/chain).........as it came with 14/48 gearing.....
B
__________________
01 XR650L,102mm JE 11.25:1..NX650 second gear,FMX650 fifth gear,ported CW head,KW valve train,MegaCycle 173X25.FCR MX pumper.42/158 NVCT needle.Cycra probend CRM,Scott`s sharkfin,Xr`s Only casesaver.FMF "Q2",Sutton Oil Cooler,Clarke 4.0,Red XR`s Only skidplate,Doubletake mirrors,Manracks Rotopax rack..one Minature Schnauzer
techforlife is offline   Reply With Quote
Old 01-04-2011, 04:17 PM   #18
mcma111
Beastly Adventurer
 
mcma111's Avatar
 
Joined: Jul 2007
Location: San Francisco,Ca.
Oddometer: 11,239
Compression Ratio

Brian,

How is it that when you put an XR piston in the XRL the compression ratio went DOWN? I thought the whole idea of doing the XR piston was to RAISE the CR. Back a couple of years when my XR600 had a melt down (dam kid) I went round 'n round with Thumper Racing trying to get a replacement 102.4 piston for my 6. He kept sending me XRL pistons which have a lower wrist pin to piston crown measurement. I found this out the hard way as I had the piston sent directly to the machinist and he bored the cylinder for it and I put it all together thinking all was good. Turned out the bike ran like a 250. After multiple attempts to figure WTF was wrong I pulled the cylinder only to find that the piston didn't come anywhere close to the top of the cylinder. DUH!!! You state the JE 10.5 piston is giving you 9.3 ?? How's that???
__________________
Steve in SF

BMW's
58 R26
79 R100s
91 R100gs

87 Harley FXRS-SP ~ 06 KTM 625 SMC ~ 72 Honda CB750/915cc ~ 92 XR600/654cc ~ 95 XR650l/675cc ~ 03 CRF450r ~ 05 CRF450x ~ 02 XR650l/675cc ~ 86 YZ490 ~ 93 YZ80 ~ 93 XR650l Project
mcma111 is offline   Reply With Quote
Old 01-04-2011, 05:34 PM   #19
cyclewizard
Beastly Adventurer
 
cyclewizard's Avatar
 
Joined: May 2007
Location: Norway/Michigan.
Oddometer: 4,797
The JE XRL 10.5.1 pistons come to zero deck height or just a few thousandths in the hole .006 to .008 at the most, they yield about 10.2.1 or so then you figure 58cc's for the chamber volume and another 4 cc's for the valve pockets.
So 0.046 for deck height, 62cc's of chamber volume 101mm bore
,82mm stroke leaves you at 10.2.1 compression depending on what the chamber and piston cc's in at.
The XR600 piston sits in the hole more than the XRL's does.
Add .086 for deck height and you have 9.3.1 comp. using it in a XRL motor.
__________________
C-dub......


Powered by CW-Pistons/cams
Wizard manufacturing....

cyclewizard screwed with this post 01-04-2011 at 06:16 PM
cyclewizard is offline   Reply With Quote
Old 01-04-2011, 06:07 PM   #20
Cumbacheech
XRated
 
Cumbacheech's Avatar
 
Joined: Oct 2006
Location: Bolton, ON
Oddometer: 823
Very good information in this thread!!!
__________________
2001 XR650L - Done for now...!!

Pics: Adventure setup, SUMO setup, Dirt setup
Cumbacheech is offline   Reply With Quote
Old 01-04-2011, 06:11 PM   #21
cyclewizard
Beastly Adventurer
 
cyclewizard's Avatar
 
Joined: May 2007
Location: Norway/Michigan.
Oddometer: 4,797
Now if you were to take the same calulations but add in a 106mm slug you would have 11.2.1 comp with a flat top at zero deck height.

What I do with the 106 pistons is clover leaf the center like we did on the old RS600 flat track motors to yield 10.2.1 comp ratio's and end with more squish band area, you can run 93 pump fuel with this design.

The old RS motors we made a pop up slug at 14.1 with the dished centers to keep our squish tight at .040 for better power and less detonation.
After clovering and milling the piston they came in at 11.5.1 but we had more quench with this design.

If you look at a combustion chamber, you will usually see these flat areas, and they will have the volume of the actual combustion chamber between them, the XRL does not have these flat spots. When the piston is compressing the mixture, as the piston nears the head, the flat areas on the head and piston come together and force the mixture from those areas to "squish" into the chamber, where the spark plug and burning mixture reside, so you achieve a more complete burn.

The quench area also runs cooler than the rest of the chamber / piston. These lower temperatures are where the "quench" comes from.
When properly designed, the quench areas can have a tremendous effect on the quality of combustion, and allow higher compression ratios, and due to this they are considered artificial octane.
By using a domed piston in a XRL and then mill a clover leaf design into the center you create more quench and squish area for cooler running and more power with less knock.
__________________
C-dub......


Powered by CW-Pistons/cams
Wizard manufacturing....

cyclewizard screwed with this post 01-04-2011 at 06:19 PM
cyclewizard is offline   Reply With Quote
Old 01-04-2011, 06:15 PM   #22
techforlife
CDI REPAIR
 
techforlife's Avatar
 
Joined: Sep 2008
Location: Moncton,New Brunswick
Oddometer: 4,239
Quote:
Originally Posted by mcma111 View Post
Brian,

How is it that when you put an XR piston in the XRL the compression ratio went DOWN? I thought the whole idea of doing the XR piston was to RAISE the CR. Back a couple of years when my XR600 had a melt down (dam kid) I went round 'n round with Thumper Racing trying to get a replacement 102.4 piston for my 6. He kept sending me XRL pistons which have a lower wrist pin to piston crown measurement. I found this out the hard way as I had the piston sent directly to the machinist and he bored the cylinder for it and I put it all together thinking all was good. Turned out the bike ran like a 250. After multiple attempts to figure WTF was wrong I pulled the cylinder only to find that the piston didn't come anywhere close to the top of the cylinder. DUH!!! You state the JE 10.5 piston is giving you 9.3 ?? How's that???
The JE XR600R piston pin is 1mm higher on the piston compared to the XRL piston........so it sits 1mm lower than the XRL JE piston would...but being a flat top piston you gain a little over stock...HeadTrama has a piston chart on TT that shows the different pin placement between the 2..

Also from what he`s found even the XRL 10.5-1 only gives a true 9.8-1 (IIRC)...seems they don`t do their homework..since the OE piston itself sits 1mm below deck...

I`ll get some links to the charts...and see if HT will make a guerst appearance since he and valvesrule went through a lot of pain with the measurements..........and definately know more about this than i do..

B
__________________
01 XR650L,102mm JE 11.25:1..NX650 second gear,FMX650 fifth gear,ported CW head,KW valve train,MegaCycle 173X25.FCR MX pumper.42/158 NVCT needle.Cycra probend CRM,Scott`s sharkfin,Xr`s Only casesaver.FMF "Q2",Sutton Oil Cooler,Clarke 4.0,Red XR`s Only skidplate,Doubletake mirrors,Manracks Rotopax rack..one Minature Schnauzer

techforlife screwed with this post 01-04-2011 at 07:07 PM
techforlife is offline   Reply With Quote
Old 01-04-2011, 06:17 PM   #23
mcma111
Beastly Adventurer
 
mcma111's Avatar
 
Joined: Jul 2007
Location: San Francisco,Ca.
Oddometer: 11,239
Quote:
Originally Posted by cyclewizard View Post


The XR600 piston sits in the hole more than the XRL's does.


I still don't get it. The XR and XRL pistons have different wrist pin to top of piston dimensions. The XRL is shorter. So how can a XR piston sit higher as you state? I still want to see one of your 720cc pistons.
__________________
Steve in SF

BMW's
58 R26
79 R100s
91 R100gs

87 Harley FXRS-SP ~ 06 KTM 625 SMC ~ 72 Honda CB750/915cc ~ 92 XR600/654cc ~ 95 XR650l/675cc ~ 03 CRF450r ~ 05 CRF450x ~ 02 XR650l/675cc ~ 86 YZ490 ~ 93 YZ80 ~ 93 XR650l Project
mcma111 is offline   Reply With Quote
Old 01-04-2011, 06:18 PM   #24
techforlife
CDI REPAIR
 
techforlife's Avatar
 
Joined: Sep 2008
Location: Moncton,New Brunswick
Oddometer: 4,239
Quote:
Originally Posted by cyclewizard View Post
The JE XRL 10.5.1 pistons come to zero deck height or just a few thousandths in the hole .006 to .008 at the most, they yield about 10.2.1 or so then you figure 58cc's for the chamber volume and another 4 cc's for the valve pockets.
So 0.046 for deck height, 62cc's of chamber volume 101mm bore
,82mm stroke leaves you at 10.2.1 compression depending on what the chamber and piston cc's in at.
The XR600 piston sits in the hole more than the XRL's does.
Add .086 for deck height and you have 9.3.1 comp. using it in a XRL motor.
Thanks ..i appreciate the post...i would be lookin for hours for all the proper info... but i`ll post the link to he chart at TT..


B
__________________
01 XR650L,102mm JE 11.25:1..NX650 second gear,FMX650 fifth gear,ported CW head,KW valve train,MegaCycle 173X25.FCR MX pumper.42/158 NVCT needle.Cycra probend CRM,Scott`s sharkfin,Xr`s Only casesaver.FMF "Q2",Sutton Oil Cooler,Clarke 4.0,Red XR`s Only skidplate,Doubletake mirrors,Manracks Rotopax rack..one Minature Schnauzer
techforlife is offline   Reply With Quote
Old 01-04-2011, 06:26 PM   #25
cyclewizard
Beastly Adventurer
 
cyclewizard's Avatar
 
Joined: May 2007
Location: Norway/Michigan.
Oddometer: 4,797
Quote:
Originally Posted by mcma111 View Post
I still don't get it. The XR and XRL pistons have different wrist pin to top of piston dimensions. The XRL is shorter. So how can a XR piston sit higher as you state? I still want to see one of your 720cc pistons.
The next time I run some 720 pistons I'll send you a picture , right now I'm sold out of them.
__________________
C-dub......


Powered by CW-Pistons/cams
Wizard manufacturing....
cyclewizard is offline   Reply With Quote
Old 01-04-2011, 06:30 PM   #26
techforlife
CDI REPAIR
 
techforlife's Avatar
 
Joined: Sep 2008
Location: Moncton,New Brunswick
Oddometer: 4,239
here`s the link to the TT thread on this......

http://www.thumpertalk.com/forum/sho...t=piston+chart

Here`s the piston chart(hope HT doesn`t mind me stealin it)

The XR600R JE piston sits lower than the XR650L JE piston does...







B
__________________
01 XR650L,102mm JE 11.25:1..NX650 second gear,FMX650 fifth gear,ported CW head,KW valve train,MegaCycle 173X25.FCR MX pumper.42/158 NVCT needle.Cycra probend CRM,Scott`s sharkfin,Xr`s Only casesaver.FMF "Q2",Sutton Oil Cooler,Clarke 4.0,Red XR`s Only skidplate,Doubletake mirrors,Manracks Rotopax rack..one Minature Schnauzer
techforlife is offline   Reply With Quote
Old 01-04-2011, 06:37 PM   #27
cyclewizard
Beastly Adventurer
 
cyclewizard's Avatar
 
Joined: May 2007
Location: Norway/Michigan.
Oddometer: 4,797
Quote:
Originally Posted by techforlife View Post
here`s the link to the TT thread on this......

http://www.thumpertalk.com/forum/sho...t=piston+chart

Here`s the piston chart(hope HT doesn`t mind me stealin it)

The XR600R JE piston sits lower than the XR650L JE piston does...









B
He's got copy rights on that your in a heap of trouble now.
__________________
C-dub......


Powered by CW-Pistons/cams
Wizard manufacturing....
cyclewizard is offline   Reply With Quote
Old 01-04-2011, 06:38 PM   #28
techforlife
CDI REPAIR
 
techforlife's Avatar
 
Joined: Sep 2008
Location: Moncton,New Brunswick
Oddometer: 4,239
Quote:
Originally Posted by mcma111 View Post
I still don't get it. The XR and XRL pistons have different wrist pin to top of piston dimensions. The XRL is shorter. So how can a XR piston sit higher as you state? I still want to see one of your 720cc pistons.
But the JE pistons are different........check out the chart.

The XRL JE piston gains almost 2mm over stock.....

The XR600R piston put in the XRL gains only .770mm more height over the stock XRL piston...but since it`s also not dished you gain the 0.770 taller in the bore and also some from not being dished...

It`s kinda 1/2 way between the XRL JE 10.5-1 and stock...

Someone correct me if i`m fudging this up...

B
__________________
01 XR650L,102mm JE 11.25:1..NX650 second gear,FMX650 fifth gear,ported CW head,KW valve train,MegaCycle 173X25.FCR MX pumper.42/158 NVCT needle.Cycra probend CRM,Scott`s sharkfin,Xr`s Only casesaver.FMF "Q2",Sutton Oil Cooler,Clarke 4.0,Red XR`s Only skidplate,Doubletake mirrors,Manracks Rotopax rack..one Minature Schnauzer
techforlife is offline   Reply With Quote
Old 01-04-2011, 06:40 PM   #29
techforlife
CDI REPAIR
 
techforlife's Avatar
 
Joined: Sep 2008
Location: Moncton,New Brunswick
Oddometer: 4,239
Quote:
Originally Posted by cyclewizard View Post
He's got copy rights on that your in a heap of trouble now.
IIRC he wants people to download it..so PhotoBuggers doesn`t take a crap...and then just thank him...sooooooooooo THANKS HEADTRAMA....

There...am i safe now...or do i have to move to Siberia

B
__________________
01 XR650L,102mm JE 11.25:1..NX650 second gear,FMX650 fifth gear,ported CW head,KW valve train,MegaCycle 173X25.FCR MX pumper.42/158 NVCT needle.Cycra probend CRM,Scott`s sharkfin,Xr`s Only casesaver.FMF "Q2",Sutton Oil Cooler,Clarke 4.0,Red XR`s Only skidplate,Doubletake mirrors,Manracks Rotopax rack..one Minature Schnauzer
techforlife is offline   Reply With Quote
Old 01-04-2011, 06:43 PM   #30
mcma111
Beastly Adventurer
 
mcma111's Avatar
 
Joined: Jul 2007
Location: San Francisco,Ca.
Oddometer: 11,239
Well that explains it, I guess. I have been using WISECO pistons....
__________________
Steve in SF

BMW's
58 R26
79 R100s
91 R100gs

87 Harley FXRS-SP ~ 06 KTM 625 SMC ~ 72 Honda CB750/915cc ~ 92 XR600/654cc ~ 95 XR650l/675cc ~ 03 CRF450r ~ 05 CRF450x ~ 02 XR650l/675cc ~ 86 YZ490 ~ 93 YZ80 ~ 93 XR650l Project
mcma111 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 04:13 AM.


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