need more power

[speedyjeeper]

I just want to understand why this sophisticated 4 valve engine does not respond well to mods? I have no intention of putting on a loud pipe because I've been there and have grown up to realize it is Suicide for our sport and other outdoor sports. what is the difference between this liquid 650 and the XR 650?? why does the XR make 20 more hp? is this engine all stroke..cams really weak or what? thanks

[CA Stu]

--- In DSN_klr650@yahoogroups.com, "speedyjeeper" wrote:

> > I just want to understand why this sophisticated 4 valve engine does > not respond well to mods? I have no intention of putting on a loud > pipe because I've been there and have grown up to realize it is > Suicide for our sport and other outdoor sports. what is the > difference between this liquid 650 and the XR 650?? why does the XR > make 20 more hp? is this engine all stroke..cams really weak or > what? > thanks

Just off the top of my head, the XR motor is higher compression and has more aggressive cams and a way better flowing head. It's not rocket science, the KLR motor is designed to be a tractor in a tractor frame and suspension, the XR is a race engine in a race bike frame and suspension. (I own both). It's a part of a whole, the XR frame and suspension is set up to go as fast as you have the balls to go across any kind of terrain, the stock KLR is set up to go at moderate speeds on mild off road stuff at the worst. For comparison, you get a stock Ford 302 motor out of a truck, it's got an "RV" cam, set up for low rpm and torque (a la KLR), you can tow haevy loads and gos slow. You slap a set of better flowing heads, an intake, carb, and a race cam on it, you change the whole characteristic of the motor. Now it develops a lot more power, at high rpm, and isnt worth beans for low rpm towing. Just because two engines have the same displacement doen't mean they're set up for the same purpose, or capable of the same performance. Thanks CA Stu

[Eric L. Green]

On Wed, 17 Nov 2004, speedyjeeper wrote:

> I just want to understand why this sophisticated 4 valve engine does > not respond well to mods?

a) "Sophisticated"?! We're talking 1985 technology here! (The KLR-650 is basically a slightly bored/stroked KLR-600). b) It's the head. The ports in the head are the restriction, not the carb, not the pipes. In addition, the shape of the combustion chamber is not optimal for perfect combustion. c) Altering the flow of the ports in the head is expensive, because there's no excess metal that can be removed to make the ports larger, thus requiring some very tricky welding work to add metal to the right places and remove it from the right places. The size of the valves is also a limit.

> Suicide for our sport and other outdoor sports. what is the > difference between this liquid 650 and the XR 650??

15 years of technological improvement? Access to modern flow simulation and combustion chamber design tools at the time the XR 650 was designed, as vs. seat-of-the-pants back when the KLR-600 was designed, and thus better engine flow and better combustion chamber design? Amazing, technology actually *improves* over time, who woulda thunk it?!

> why does the XR > make 20 more hp?

It doesn't. It makes 10 more hp, according to actual measurements at the back wheel (as vs. advertising claims). Granted, the difference between 34hp and 44hp on a bike that's quite a bit lighter than the KLR is a kick in the pants. A 33% improvement in horsepower is nothing to sneer at by any means. -E

[Streetfighters]

So, I guess the question is, Will the XR650 motor fit in a KLR chassis? (ducking) Geoff-

----- Original Message ----- From: "Eric L. Green" Sent: Wednesday, November 17, 2004 5:21 PM Subject: Re: [DSN_klr650] The KLR power deal? > > On Wed, 17 Nov 2004, speedyjeeper wrote: > > I just want to understand why this sophisticated 4 valve engine does > > not respond well to mods? > > a) "Sophisticated"?! We're talking 1985 technology here! (The KLR-650 is > basically a slightly bored/stroked KLR-600). > b) It's the head. The ports in the head are the restriction, not the carb, > not the pipes. In addition, the shape of the combustion chamber is not > optimal for perfect combustion. > c) Altering the flow of the ports in the head is expensive, because > there's no excess metal that can be removed to make the ports larger, thus > requiring some very tricky welding work to add metal to the right places > and remove it from the right places. The size of the valves is also a > limit. > > > Suicide for our sport and other outdoor sports. what is the > > difference between this liquid 650 and the XR 650?? > > 15 years of technological improvement? Access to modern flow simulation > and combustion chamber design tools at the time the XR 650 was designed, > as vs. seat-of-the-pants back when the KLR-600 was designed, and thus > better engine flow and better combustion chamber design? Amazing, > technology actually *improves* over time, who woulda thunk it?! > > > why does the XR > > make 20 more hp? > > It doesn't. It makes 10 more hp, according to actual measurements at the > back wheel (as vs. advertising claims). Granted, the difference between > 34hp and 44hp on a bike that's quite a bit lighter than the KLR is a kick > in the pants. A 33% improvement in horsepower is nothing to sneer at by > any means. > > -E >

[txklr650]

in the old days we put water in the intake for a short time "it will get hot"

[John Kokola]

Sounds like "epoxy porting" might work here (building up certain areas with epoxy) unless someone knows better (most likely). --John Kokola

> -----Original Message----- > From: Eric L. Green [mailto:ericnospam@...] > > c) Altering the flow of the ports in the head is expensive, because > there's no excess metal that can be removed to make the ports > larger, thus > requiring some very tricky welding work to add metal to the right places > and remove it from the right places.