70+ Hp Xr650l


83 replies to this topic
  • HawkGT

Posted December 02, 2006 - 08:26 AM

#1

Is 70+hp possible in a XR650L engine? I'm thinking it is not possible without a major shot of juice but I wanted to get some more opinions.

What would 717cc, cam, porting, carb, and exhaust get you?

  • simon@vic

Posted December 02, 2006 - 10:05 AM

#2

anything it possible. but I'm going to say no!

  • RC30

Posted December 02, 2006 - 11:47 AM

#3

Ciao HawkGT.

Mmmmmh……

Here in Italy Tecnobike garage has implemented to 68,1 HP the max power of a 650R engine with HRC cam, higher compression, bigger valves, modified piston, FCR carburettor, head flow modified, exhaust system..........

.........then I don’t think that is possible in an air cooled engine...........


Ciao Piero

  • Owyhee

Posted December 02, 2006 - 03:18 PM

#4

You can glue two 650ls together (35 hp + 35 hp =70 hp).

Would a four wheeled dirtbike be a quad?

"O"

  • frankstr

Posted December 02, 2006 - 06:50 PM

#5

Juice ..what Nitrous...It would not last long....And I don't believe
you would reach the 70+ Hp....You can always dream....:worthy:

:D :prof:

  • XR650L_Dave

Posted December 04, 2006 - 09:04 AM

#6

I bet you could get 70hp out of an XRL (punch it out, high comp, cam, port it, big carb, ...) but where the heck would all the heat go?

It'd cook itself right nice.

Dave

  • XR_RON

Posted December 04, 2006 - 01:59 PM

#7

Ive seen 67hp from a factory backed XR680 baja race bike,cant remember what magazine it was.

  • crmc33

Posted June 05, 2007 - 07:06 AM

#8

70HP would be possible with a lot of tuning work.
The heat wouldnt be a big problem with an oil cooler. But to get this sprt of power without turbos/NO2/supercharging would mean high compression, bigger valves, reangled and ceramic plated aluminium bore.
Its worth bearing in mind that the top five Manx Norton racers used in the classic scene here in the UK are putting out 60HP-65HP at the back wheel. This is from an aircooled engine designed 50 years ago, still using pushrod operated valves, but with lots of hi tech mods and materials inside. The FWR replica engines alone cost $20K!!
I'll be happy if I can get 60HP from my XRL !!
Anymore than that and Id be looking to change to a more modern water cooled engine for ease of use and starting!!

I believe there are kart racers in Finland using the XRL (NX650) engine and they put out 67HP. But they race them flat out and dont need much in the way of midrange power.

Im pretty sure supercharging would get it over 70HP as the 5 valve Yam singles can be boosted to 90HP with one fitted.

  • Trail_Ryder

Posted June 05, 2007 - 07:14 AM

#9

Years ago I read about a XRL 775cc, which used a piston for a Kawasaki Vulcan, I think. The article was in DualSporter magazine. It was good for 130+ MPH with stock gearing and required a second gel battery to start it.

My buddy's old, air cooled XR-based Honda Factory RS600 Flat Track bike put out 72 HP.

Almost anything is possible if your willing to spend enough money.

  • Billahjack

Posted June 05, 2007 - 12:24 PM

#10

Just found this in my crack pipe....might be good for 100 HP if you have a big bucket of cash and some talented engineers and machinists to pull it off.

What if you changed a 650L motor into a direct injection two stroke retaining the overhead cam? It would either run off of methanol or race-gas, no premix. New cam profiles with a 1/2 stock-diameter timing gear for 2-stroke operation.

Add a supercharger to aid with exhaust scavenging. Also, recess the piston top and add a scavenging ridge to make the air tumble in the cylinder over 4K RPM. Compresion would be dropped to about 8:1 to run 8-10 PSI boost. I'm guessing that it would have stump-pulling torque off-idle with a nasty hit as soon as the intake charge begins tumbling efficiently over 4k RPM.

Shoot for a torque peak around 7,000 RPM like the insane custom aftermarket Banks Turbo Diesels. Redline would still be around 8,500.

Wrap copper tube around the fin recesses to install water cooling. Make a stand-alone electric pump and radiator system. Titanium valves with reflective cermaic coatings would be necessary to keep the meltdown from occuring. Coating the combustion chamber, piston, cylinder and exhaust port with heat reflective ceramic material would also be necessary.

Water injection would probably have to be added to keep the detonation to a minimum.

Now you will have to gut your engine and transmission for all new internals to handle the torque. Also, you will need to weld stiffeners to the outside of the engine/tranny case to keep it from cracking.

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  • Captain Midnight

Posted October 09, 2007 - 10:26 PM

#11

I'm building a 70 HP motor. My first motor was bored, 10 to 1 piston, cam, ported, FCR carb, exhaust, light flywheel. It made 52 HP. This one is fuel injected. I'm going to use a Mitsubichi turbocharger.

  • nukinfutz

Posted October 10, 2007 - 04:37 AM

#12

http://www.trickraci...nto 1000cc.html

nuff sed!!!

  • philipstjohn

Posted October 10, 2007 - 05:22 AM

#13

Is 70+hp possible in a XR650L engine? I'm thinking it is not possible without a major shot of juice but I wanted to get some more opinions.

What would 717cc, cam, porting, carb, and exhaust get you?


You can get together with the guy who says his XRR will do 140mph! :confused: :confused: :confused: :confused:

  • Billahjack

Posted October 10, 2007 - 06:58 AM

#14

With a turbo, it is in the realm of possibility, although you run a high risk for meltdown with an air-cooled engine. You need a small turbo. I used a Garrett prototype for a twin turbo diesel Mercedes on a CBR600F2 motor in college. The compressor housing was about 5" O.D. Anything bigger and you will suffer major lag. Also, with a thumper, you get a big pulse hitting the turbine as opposed to 4 smaller pulses for every 2 engine revolutions. This gives you more lag and less turbine efficiency.

We tried the same turbo on a CR125. Couldn't get it started, the two stroke air flow was messed up.

Post some pictures of your project! This sounds pretty cool.

  • martinfan30

Posted October 10, 2007 - 08:57 AM

#15

i think its possible, but with extreme mods to the eng. i dont think the trans would hold up either. you would prob. split the case in 2.

also, can you say thermo-nuclear meltdown?

  • stepho

Posted October 10, 2007 - 09:15 AM

#16

Hi at our shop we did get a 707 with fuel injection to do 80 hp at the crank. but we build our own pistons,changed intake angle, oil pump, oil squirter and plenty of mods to each engine. But not cheap. By the way 140 is capable if you have the right body work ( see avatar).

  • Maroast

Posted October 10, 2007 - 09:15 AM

#17

http://www.trickraci...nto 1000cc.html

nuff sed!!!


wow. Do you think you could run that on a bike and live?

  • martinfan30

Posted October 10, 2007 - 09:30 AM

#18

Hi at our shop we did get a 707 with fuel injection to do 80 hp at the crank. but we build our own pistons,changed intake angle, oil pump, oil squirter and plenty of mods to each engine. But not cheap. By the way 140 is capable if you have the right body work ( see avatar).


an R engine?

  • stepho

Posted October 10, 2007 - 09:32 AM

#19

nope its a L.

  • martinfan30

Posted October 10, 2007 - 09:40 AM

#20

nope its a L.


really! how do you manage the heat? is it a racer or a street bike? have any pics or anything?





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