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Thread: KTM 450 XCW snowbike build

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    Default KTM 450 XCW snowbike build

    I am wanting to build a 450 xcw snowbike engine, heres what I have come up with so far:

    - I am going to be using a 2012-2015 engine so I can go with the 520 BB kit

    I know several have added a 6th gear to their sxf for use in a snowbike application. I am a bit different, and I want to replace the first 5 wide ratio gears on the XCW to close ratio SXF gears (1-5 gears). Reasons to go with a XCW engine instead of SXF:

    - Has electric start and backup kickstarter

    - Has a bigger stator so you can run lights, heater, etc.

    - Already has 6 speeds.



    The downfall of the XCW engine is that its not revy and doesnt have the top end like an SXF. So the question is: what can be done to give it more top end?
    - I am going to use a snowbike specific ECU setup made by Raze motorsports (changes timing, maps, etc)

    - I want to put in performance camshafts, but I cant find any options. I only see upgrades for SXF models. Can the SXF cams be used on XCW? If not, can I put a SXF head on the XCW to use the performance cam?


    - Given the option, which engine should I pick as a base for the build: 450 or 500 XCW? (2012-2015 model)

    Thanks in advance!

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  3. #2
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    Default Re: KTM 450 XCW snowbike build

    Also, for 2012-2015 the XCW & EXC engines are exactly the same correct?

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    Default Re: KTM 450 XCW snowbike build

    Yes the xcfw and EXC engines are exactly the same. There are no cam options for the exc/xcfw. You can install a sxf head on the exc motor. The sxf cam is more aggressive and makes broader power when used with our 520 kit over the EXC head/ cam.
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    Default Re: KTM 450 XCW snowbike build

    Quote Originally Posted by TravisD37 View Post
    Yes the xcfw and EXC engines are exactly the same. There are no cam options for the exc/xcfw. You can install a sxf head on the exc motor. The sxf cam is more aggressive and makes broader power when used with our 520 kit over the EXC head/ cam.
    Thanks for the info!


    I got an email back from Dan crower in response to XCW performance camshafts: "send us your cam its 475$ to weld it and grind to a power spec for super moto or top speed type use .
    a new cam is possible also , 698$"
    Does the SXF head have any advantage over the XCW head? larger ports, higher flow, etc? which head should I go with if I plan to port it?
    Last edited by Dave500; 10-14-2020 at 05:40 PM.

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    Default Re: KTM 450 XCW snowbike build

    I bet you can not improve on either SX or EXC head with porting, they are state of the art!! On the difference between SX & exc heads, I 1/2 way understand the issue but not qualified to explain, Dan Crower could, he EXC has roller rockers and the SX has "finger followers" the difference is related to the radius of the roller (guess 5mm) the radius the finger follower (huge, maybe 50mm??) and the valve action that can be made with either, EXC user want it to last 100 of hours, SX rider wat it to make more power!
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    Default Re: KTM 450 XCW snowbike build

    I have done some Googling, but could not find the wanted info on the 12-13 sxf or xcw heads. Is there an engine builder out there who would know if the SXF head has any advantage over the XCW head? larger ports, higher flow, etc? and which head should I go with if I plan to port it? I feel like there would be much benefit from head porting as its going to be a BB.

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    Default Re: KTM 450 XCW snowbike build

    Also, I heard that on some years the SXF had a larger throttle body bore than the XCW/ EXC. Anyone know?

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    Default Re: KTM 450 XCW snowbike build

    Quote Originally Posted by Dave500 View Post
    Also, I heard that on some years the SXF had a larger throttle body bore than the XCW/ EXC. Anyone know?
    For both my last two bikes I have used the TB from the SXF bike. My 2020 Six Days 500 had 642 imprinted on the butterfly. On the TB from the 450 SXF bike, it says 644 so I am assuming its a 44MM vs a 42MM. I first began using the SXF ThrottleBodies back in 2014 when Dave Simon of BestDualSportBikes.com sold me a slightly modified SXF TB for my 15 500 XCW. This last year he tested the SXF TB and found it ran just a tad leaner throughout the RPM range on a GET ECU. I also noted that the cost of the SXF TB is about $100 less on my Six Days. I always like to have a spare TB around for trouble shooting. I have run both TBs on my 2020 Bike and they both perform very well. Probably would need a dyno to prove if one makes more HP than the other. I also run the Euro intake boot on all my FI bikes along with a G2 Throttle Tamer.

    2020 500 Six Days Suspension by KreftMoto, Seat by Renazco Racing, GET powered with larger ThrottleBody and BDSB endcap.
    2015 500 XCW Euro Map, Full Dean Burke Motorsports Ohlins Suspension with Huck Valves in the forks
    2013 350 XCFW Vortex & A Kit SP Suspension ....lucky son

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    Default Re: KTM 450 XCW snowbike build

    Specifically for the 2013 SXF, I was able to find it has at 44mm Throttle body: "The fuel injection system has been radically reworked for the new MY2013 four stroke range with Keihin supplying a new EMS with an increased throttle body size up from 42mm to 44mm"

    The 2013 450 XCW does has a 42mm throttle body.

    Is the SXF throttle body a direct replacement onto the XCW? or do I need to swap the boots also?

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    Default Re: KTM 450 XCW snowbike build

    Quote Originally Posted by Dave500 View Post
    Is the SXF throttle body a direct replacement onto the XCW? or do I need to swap the boots also?
    The sxf t/b will drop right in except for the wiring harness injector plug and fuel line they are different.
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