Power of R over the L


138 replies to this topic
  • Ferdinand

Posted June 21, 2006 - 08:40 PM

#21

You mean on an "R"

Posted Image


I think he meant on a XR 650 period. R or L :busted:
Ride Red. :excuseme:
BTW Nice pic! :bonk:

  • nxridge

Posted June 22, 2006 - 02:54 AM

#22

L or R , its the same ticket , lol

  • TREADMARKS

Posted June 22, 2006 - 02:57 AM

#23

The cam fits either a XR600 or XR650L it is a regrind of a stock cam. It's just more then a Hot Cam stage one.
INTAKE LIFT: 9.2 mm
INTAKE DURATION: 262°
EXHAUST LIFT: 9.2mm
EXHAUST DURATION: 260°

With high compression pistons you have to machine the piston for valve clearance. As you would clay test any cam installation. A cam like this would not be a drop in installation as is the stage one with a stock piston.

Hot Cam stage one:

INTAKE LIFT: 8.8 mm
INTAKE DURATION: 258°
EXHAUST LIFT: 8.8mm
EXHAUST DURATION: 258°


Great information.

Where can I purchase one of these? Are they still available?

  • mgs781

Posted June 22, 2006 - 03:37 AM

#24

Any cam other than Hotcams or OEM honda is a hard-welded regrind. This is a much harder surface than the OEM rockers. Reground cams will require hard-welded rockers. If you try to run this cam without, you will chew up your rockers. The cost to hard-weld rockers is $40-60 each, which makes for an expensice project. Hotcams is the most cost effective solution to the stock L cam.

Bruce is correct in everyway with regards to the lethargic stock cam. Hotcams and OEM side by side, the differences in duration alone is comical.

By the way. I run a L with a 10.25:1 piston, Hotcams, Edelbrock (bad choice), and yosh. My friend has an uncorked R. I am never more than a bike length behind. I have not gotten it on the dyno yet, but I would have to guess mid to upper 40s in horse power.

Don't get me wrong, the stock L is slow. But with a few hundred in engine work, the bike can be made to perform close to the R.

MGS

  • Jawmail

Posted June 22, 2006 - 04:15 AM

#25

Any cam other than Hotcams or OEM honda is a hard-welded regrind. This is a much harder surface than the OEM rockers. Reground cams will require hard-welded rockers. If you try to run this cam without, you will chew up your rockers. The cost to hard-weld rockers is $40-60 each, which makes for an expensice project. Hotcams is the most cost effective solution to the stock L cam.

Bruce is correct in everyway with regards to the lethargic stock cam. Hotcams and OEM side by side, the differences in duration alone is comical.

By the way. I run a L with a 10.25:1 piston, Hotcams, Edelbrock (bad choice), and yosh. My friend has an uncorked R. I am never more than a bike length behind. I have not gotten it on the dyno yet, but I would have to guess mid to upper 40s in horse power.

Don't get me wrong, the stock L is slow. But with a few hundred in engine work, the bike can be made to perform close to the R.

MGS


Good stuff on the cams, so the Hotcams piece is a drop-in. Can you just put that in and not do the piston at the same time? Seems like an inexpensive power increase.

  • mgs781

Posted June 22, 2006 - 06:54 AM

#26

Some have done just the cam, but I would do the piston at the same time. It really isn't that much more money or work. The stock 8.3:1 compression ratio of the L is very low. Most turbo motors run around 8:1. Honda did this to reduce the stress on the motor for street riding, as street riders rack up much more mileage than dirt riders.

Everyone assumes that the compression boost with increase opperating temperatures, but I never see over 230F and that is without an oil cooler. 10.25:1 cr is great for an air/oil cooled motors like the L.

Do the piston and cam and have close to the R's power with e-start.

MGS

  • ghoti

Posted June 22, 2006 - 07:16 AM

#27

Some have done just the cam, but I would do the piston at the same time. It really isn't that much more money or work. The stock 8.3:1 compression ratio of the L is very low. Most turbo motors run around 8:1. Honda did this to reduce the stress on the motor for street riding, as street riders rack up much more mileage than dirt riders.

Everyone assumes that the compression boost with increase opperating temperatures, but I never see over 230F and that is without an oil cooler. 10.25:1 cr is great for an air/oil cooled motors like the L.

Do the piston and cam and have close to the R's power with e-start.

MGS

What kind of gas milage do you average? I am in the 48mpg range with 15/48, e-series, uni, carb mods, 140/80.

  • justicedone

Posted June 22, 2006 - 08:45 AM

#28

I will keep my ultra reliable, magic buttoned bike over a sore leg anyday. It takes a lot of skill and balls to handle an L through the real stuff, but its all the more fun when dun'

word

  • BWB63

Posted June 22, 2006 - 09:27 AM

#29

To add just a little more of my $.02 worth. The crank on the XR650L can safely handle (I do mean bullet poof) 70bhp! That would be 55rwhp on a dyno. They have been known to handle more but, at a cost to life of the crank. So, all those that think you are keeping the bike much more reliable with the ultra low compression are missing out. The reason for the lame cam and low compression is for emissions and low grade fuel that is used on street bikes. Air cooled bikes ping much easier then water cooled, have a lot more hot spots, vapor lock much easier, and have a shorter cylinder life. If you what to run 87 octane on hot days for a reliable bike then you are right, You need the low compression piston but, then again you wouldn't be the power hungry guy looking for that ear to ear crazy grin that the few other nuts-0-guys are looking for. They do have softer regrinds these days but, harder rockers are the ticket. The stage one cam is more then enough if you are not racing.

  • mgs781

Posted June 22, 2006 - 09:48 AM

#30

To add just a little more of my $.02 worth. The crank on the XR650L can safely handle (I do mean bullet poof) 70bhp! That would be 55rwhp on a dyno. They have been known to handle more but, at a cost to life of the crank. So, all those that think you are keeping the bike much more reliable with the ultra low compression are missing out. The reason for the lame cam and low compression is for emissions and low grade fuel that is used on street bikes. Air cooled bikes ping much easier then water cooled, have a lot more hot spots, vapor lock much easier, and have a shorter cylinder life. If you what to run 87 octane on hot days for a reliable bike then you are right, You need the low compression piston but, then again you wouldn't be the power hungry guy looking for that ear to ear crazy grin that the few other nuts-0-guys are looking for. They do have softer regrinds these days but, harder rockers are the ticket. The stage one cam is more then enough if you are not racing.


I did speak with one guy that was using the L motor to road-race with (custom tube frame sportbike). He said that prolonged high acceleration rates on the motor will cause the counter balancer to slip on its shaft (press fit). If this happens the motor is junk as the counter balancer will slam into the crank at speed. The racer seemed to indicate that he was rev'ing the motor to over 10,000rpm.

I have seen pictures of a stock L with this condition. The owner claimed to have been "just" riding along!

I run 93 and have never had a ping. I wouldn't do Edelbrock again, the FCR is more work to tune but has the ability to get finer adjustments which will give better performance.

Gas mileage is in the 40-50 depending on how I ride. The bike is setup for supermoto with a smaller rear spocket to get back to the correct final drive.
I run the Aloop kit and only have 1.9 gallons in the tank, I have to fill up to and from work. I am a slave to fashion, check ouy my garage.

MGS

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  • Bodhisattva

Posted June 22, 2006 - 09:14 PM

#31

what would i need to do to my 06 L to beat my friends 625 smc lc4 ktm? could i?

Do you guys run 87 or 92 in your L? stock.

wouldent all the modding decrease reliablity?

  • XR650L_Dave

Posted June 23, 2006 - 08:59 AM

#32

what would i need to do to my 06 L to beat my friends 625 smc lc4 ktm?


best bang-for-the-buck would be to work on the seat-pegs-bar interface component.

Dave

  • Bodhisattva

Posted June 23, 2006 - 02:27 PM

#33

sorry but jeremy mcgrath could not make my stock L beat a ktm smc 625 on the road in a straight line race.

  • XR_mad

Posted June 24, 2006 - 08:18 AM

#34

what would i need to do to my 06 L to beat my friends 625 smc lc4 ktm? could i?

Do you guys run 87 or 92 in your L? stock.

wouldent all the modding decrease reliablity?

sell it and buy an R maybe :excuseme:

  • BWB63

Posted June 24, 2006 - 08:35 AM

#35

You would need to go 675cc, 10.25:1 Piston. Hot cam (or spiecal regrind), TMR40 Mikuni carb, and all the usual valve train, connecting rod, clutch upgrades to keep the engine bullet proof, Header/Muffler, air filter........ Then strip the bike of the 30 pound extra weight. I do think then it would be a close race with the XR675L coming out ahaed. It would have to be done right and the XR675L be pumping 50hp to the rear wheel. The KTM stock?

  • Bodhisattva

Posted June 24, 2006 - 11:23 AM

#36

I belive the ktm is stock save for a pipe and silencer combo.
Hey bwb63...how much would all those mods cost?
Could my buddy and i put them all on, his skill level with bikes is up there.

  • BWB63

Posted June 24, 2006 - 12:06 PM

#37

You would need to send the cylinder out to bored/sleeve it, and have the connecting rod installed/crank balanced but, if you are going with a HotCam and your bud can do a valve job, then yes, you can do it. $1K I wouldn't skimp, get a Carrillo connecting rod or Falicon Connecting Rod, Black Diamond stainless steel valves, make sure your valve guides are good or get new better ones and the best timing chain. I always costs more then you think...... For the best info and most honest dealings go to Luke's Racing, they will steer you the right way even if you don't buy from them.

http://www.lukesracing.com/

  • Bodhisattva

Posted June 24, 2006 - 03:40 PM

#38

Thanks for the info

  • justicedone

Posted June 24, 2006 - 05:42 PM

#39

I remember years ago, maybe 1993, a good friend of mine who had many years of motocross racing under his belt, bought a brand new Suzuki DR350, bone stock off the showroom floor. I had a Yamaha TriZ250 at the time(85) and we went out to ride the hills and some serious single track motocross areas. He started flinging that damn DS over triples and flying farther than humanly would seem possible, guys on the track just stopped riding and watched the show.

It was sick, and impressive to say the least, whipping that under-suspended bike and table-topping jumps and mastering the track with ease. The CR and YZ crowd shook their heads in disbilief, as did I.

The damn bike was bottoming out so hard I thought sure a cracked frame, blown tires and bents forks and rims were soon to fallow, but besides the rear plate and signals blowing off from landing too hard, it held up pretty well.

I think my buddy would have had a serious career in motocross, but he got drunk with some losers and they decided to rob a bank one day, got caught and ended up doing 20yrs...
shit happens I guess ???

Anyway, the point is the bike doesnt really matter as much as the skill of the rider, and the bottom line is having fun and not ending up dead or crippled (or robbing a bank/dropping the soap)...mmmmkay

so if you own any bike that allows you to go ride in the hills, or supermoto the streets, be happy and make some buddies to ride with for some good times...
stop hating those who dont own your bike, or are better or lesser riders, we only go around the big track, once in life so shut up and ride !!!

:excuseme:

ha ha :bonk:

  • Ferdinand

Posted June 24, 2006 - 09:05 PM

#40

Well Said! :bonk: Whether it's on Suzuki, Kawasaki, Yamaha, KTM, ATK, Honda 650r :busted: (yeah we know its faster, more powerful, more blah, blah, blah(yawn) than the L ), Honda 650L, or any other Honda thumper, even a Honda Cub or dare I say it an ATV, enjoy the ride! :excuseme:





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