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Author Topic: Twin port dual carb rotary  (Read 5967 times)

motorman45

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Re: Twin port dual carb rotary
« Reply #60 on: June 16, 2020, 11:47:48 pm »
I'm wondering how the length of the intake runners is effecting throttle response ?  Probably no way to tell other than trial and error. Good luck.   :)

 i think your right. there is something to the tuned length on the shorter intake and also how i tuned the header. the exhaust on it was dialed in for the long runner setup and there are returning exhaust pulses during overlap. im going to try a longer velocity stack and alter the progressive linkage, you can see in the video some vapor pulses spitting back from the carbs.
 i feel like it is still well worth the time i put into it. ill get it to work ideally im sure, and it looks pretty cool , here's a shot with the cut hood
« Last Edit: June 18, 2020, 12:23:17 am by motorman45 »
72 Cheetah 440 sachs
72 Cheetah 303 custom
71 Puma 303 mod
71 lynx 303 mod

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    motorman45

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    Re: Twin port dual carb rotary
    « Reply #61 on: September 24, 2020, 12:18:27 am »
    Updated this project. the twin HR tillotsons worked but it seemed like too much air in the secondary port, so i swapped that one for an HL and it is much smoother transition to 7k and even better throttle response. ill make a video of it at some point soon . cant wait for snow to run this against something else.
     this thread should be moved to Customs if someone would do that.
    72 Cheetah 440 sachs
    72 Cheetah 303 custom
    71 Puma 303 mod
    71 lynx 303 mod

    holleytool

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    Re: Twin port dual carb rotary
    « Reply #62 on: September 24, 2020, 12:35:00 pm »
    Very good information and great job on the 303 mod!
    pett member 93

    chris r

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    Re: Twin port dual carb rotary
    « Reply #63 on: September 24, 2020, 05:37:35 pm »
    That is a cool set up for sure. Like to hear it run.
    If you can't look back on your younger self and realize you were an idiot, you're probably still an idiot.

    Skier76

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    Re: Twin port dual carb rotary
    « Reply #64 on: October 04, 2020, 11:01:23 pm »
    Awesome work! Think snow...it's getting closer in SoVT.
    1996 Puma 2-up
    1996 Jag

    motorman45

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    Re: Twin port dual carb rotary
    « Reply #65 on: October 15, 2020, 09:02:17 pm »
    Glad you guys are liking this. made a new video

    https://youtu.be/DPn5hpj4u6w

    here it is finally running again.  a new exhaust and with a longer header in the can with a front exit fabbed from an old cat can. the smaller HL cab swapped in on the peripheral port manifold. seems to rev easier to 7k and has a cleaner response that before. still more tinkering to do .. and get snow.
    72 Cheetah 440 sachs
    72 Cheetah 303 custom
    71 Puma 303 mod
    71 lynx 303 mod

    Bugs

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    Re: Twin port dual carb rotary
    « Reply #66 on: October 15, 2020, 09:59:17 pm »
    nice sounds good

    Mr_Plow

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    Re: Twin port dual carb rotary
    « Reply #67 on: October 17, 2020, 02:43:52 pm »
    I like it! Really cool!
    I hope it runs that good on snow!
    My sled picture albums: Wild-One, '65 Arctic Cat, AMF, Others
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    motorman45

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    Re: Twin port dual carb rotary
    « Reply #68 on: November 09, 2020, 03:21:36 pm »
    I cannot wait to test on snow.   finished a new hood for this. new decals thanks to the sled printer, have a new seat in the works soon. decals are more purple than in these pics. just noticed how pink they look
    « Last Edit: November 10, 2020, 01:24:42 am by motorman45 »
    72 Cheetah 440 sachs
    72 Cheetah 303 custom
    71 Puma 303 mod
    71 lynx 303 mod

    chris r

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    Re: Twin port dual carb rotary
    « Reply #69 on: November 10, 2020, 11:33:40 am »
     8)
    If you can't look back on your younger self and realize you were an idiot, you're probably still an idiot.

    motorman45

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    Re: Twin port dual carb rotary
    « Reply #70 on: November 19, 2020, 12:52:44 pm »
    New custom seat on its way, I used a foam for a 72 puma, filled the back trunk cutout and reshaped it . sending to the cover maker today. messy reshaping this stuff but will look pretty good i hope
    « Last Edit: November 19, 2020, 04:00:37 pm by motorman45 »
    72 Cheetah 440 sachs
    72 Cheetah 303 custom
    71 Puma 303 mod
    71 lynx 303 mod

    Skier76

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    Re: Twin port dual carb rotary
    « Reply #71 on: November 22, 2020, 01:01:53 pm »
    Sweet! Looking really good!
    1996 Puma 2-up
    1996 Jag