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Thread: hcci test

  1. #16
    Join Date
    30th April 2011 - 04:57
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    bsa. honda. aprilia
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    england
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    388

    you tube

    I've tried to add you tube video... but I give up...its on there ...nitro/petrol mix with igniter

  2. #17
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    30th April 2011 - 04:57
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    bsa. honda. aprilia
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    i


    Sort of fires but my fuel delivery system is crap !! It also doesn't want to know at all without the igniter battery..

  3. #18
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    7th September 2011 - 00:26
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    bsa bantam
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    england
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    47
    Hi Nigel,
    Great to see that you are still doing crazy, innovative and inspiring stuff, hope you get there mate, can`t wait for a new `Midlands`, perhaps next year.

    Regards, Trevor

  4. #19
    Join Date
    30th April 2011 - 04:57
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    bsa. honda. aprilia
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    england
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    Sealing issues

    Well this is my design for my adjustable combustion head which is a rehash of the one i made earlier. It wouldnt seal ... If anyone has any advise on what i intend to do please comment.so Maybe it wouldn't be another wasted effort..Click image for larger version. 

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  5. #20
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    28th August 2015 - 00:01
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    1975 Hodaka Wombat
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    Eugene, Oregon, USA
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    237
    We did some testing with a 26 cc racing engine on glow ignition. We couldn't get the plugs to hold up. The plugs that could stand the pressure wouldn't constantly fire and the others blew out the center element. We probably needed to play with head volumes. On spark ignition it ran well on 15% nitro model fuel, but burned the electrodes off the plug on 40% nitro. I wrote an article on model engine head design. See namba.com/content/library/propwash/2019/october/4/#zoom=z if that helps.

    Model "diesels" depend on a close fit with the moveable head and the cylinder. They're adjusted by a central screw. I'm not sure how well that would work on a larger bore. Our luck with this style piston on a 36 cc engine wasn't good. The head is a less exacting application, though. It needs to be very close to a zero clearance fit in a very round bore.

    Lohring Miller

  6. #21
    Join Date
    30th April 2011 - 04:57
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    bsa. honda. aprilia
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    england
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    sealing...

    Quote Originally Posted by lohring View Post
    We did some testing with a 26 cc racing engine on glow ignition. We couldn't get the plugs to hold up. The plugs that could stand the pressure wouldn't constantly fire and the others blew out the center element. We probably needed to play with head volumes. On spark ignition it ran well on 15% nitro model fuel, but burned the electrodes off the plug on 40% nitro. I wrote an article on model engine head design. See namba.com/content/library/propwash/2019/october/4/#zoom=z if that helps.

    Model "diesels" depend on a close fit with the moveable head and the cylinder. They're adjusted by a central screw. I'm not sure how well that would work on a larger bore. Our luck with this style piston on a 36 cc engine wasn't good. The head is a less exacting application, though. It needs to be very close to a zero clearance fit in a very round bore.

    Lohring Miller
    thanks, ill take a look at the article.. i had hoped my original piston ring sealing method would be the way to go and maybe i should have another go at it but improve my machining... or even try and press in a pre plated sleeve with an opposing modified piston. at least that wouldn't need me to up my game on the machining front.

  7. #22
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    30th April 2011 - 04:57
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    bsa. honda. aprilia
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    england
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    latest

    tried the threaded piston ..... but still no satisfactory seal,,

    Click image for larger version. 

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    so Ive made a sleeve from a weed whacker cylinder and pressed that in and machined the piston down and coupled it to a shaft... my starter motor has burnt out so testing this is on hold till i can replace it..
    Last edited by breezy; 4th March 2021 at 06:29. Reason: attachment didint load

  8. #23
    Join Date
    30th April 2011 - 04:57
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    bsa. honda. aprilia
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    england
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    threaded piston

    Click image for larger version. 

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ID:	348646 piston threaded, managed to groove the internal shaft to incorporate wire for a glow plug, which was then sleeved with chrome plated brass tube,
    Last edited by breezy; 4th March 2021 at 06:33. Reason: more info

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