Dakar Dazed II - the return! Part 1: Project LC4-50

Discussion in 'Racing' started by JMo (& piglet), Jan 26, 2013.

  1. JMo (& piglet)

    JMo (& piglet) Gone a bit Baja

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    Yes - thats right, there was a sleeved down version of the previous generation LC4, which kind of was the inspiration for this project to be honest!

    However, once we got a 690 engine apart, we realised that a narrower bore just wasn't going to work with the shape of the combustion chamber head - the valves and everything are just too big to make any meaningful reduction...

    However, John did a few calculations, and worked out that by having a longer rod and a shorter stroke, we could get the required capacity while retaining the original barrel and bore - all we would have to do is modify the piston profile to regain the compression that we'd lose...

    As I mentioned in my initial post, there is a direct benefit here for regular 690 owners too (including the 654 and 690cc variants), in that it will be straightforward enough to also create a stock replacement together with a hi-comp piston for a regular 690 too - all from the same blanks... in fact because everything can be computer modeled beforehand, it is perfectly possible to dial in the compression ration you want, and shape the piston as required!

    It is certainly John's intention to have a batch of 690 pistons available for sale as soon as possible, if only to help offset some of the engine development costs, which you might imagine are quite significant...

    I spoke with John this afternoon in fact, and he is making good progress with the prototype crank - typically he loves to do things that people say can't be done - and sure enough, he has managed to split a stock 690 crank (by making his own tool), and welded it up - and will begin machining it this coming week - photos to follow of course!

    Jx
    #41
  2. JMo (& piglet)

    JMo (& piglet) Gone a bit Baja

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    Hi Tome! - don't worry, you're not late at all - the party is only just beginning!!!

    Jx
    #42
  3. JMo (& piglet)

    JMo (& piglet) Gone a bit Baja

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    Hi BD - thanks for those dates! - It's possible the US bike would be ready by the end of May, but I think realistically, the trip is unlikely to happen before the end of June and into July at the moment- making the most of the summer, and have some fun in the Rockies en route too! (ahem, I mean 'serious altitude testing' in Colorado of course!)

    That way we can ship the bike during August, prep it in the UK during September, and have both team bikes ready for the Maroc Rally in October - that is the pencilled plan at the moment anyway!

    Jx
    #43
  4. Jurassic

    Jurassic Long timer

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    Are you able to carry over your 2013 Dakar start Jenny (I'm sure I read this somewhere) to save the uncertainty of the normal entry process?
    #44
  5. juames

    juames Have Fun, Don't Die!

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    Don't forget probably the biggest...the Roaming Rally just over the Can-US boarder in mid June! Some fun riding to test the new bike out on, and we'd LOVE to have a chance to see the LC4-50 (not to mention JMo and Piglet) in person! :clap:freaky And Montreal would be a great port to ship the bike to the UK from.
    #45
  6. Sparrowhawk

    Sparrowhawk Long timer

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    I'm not sure how much time you have but there are some great established off tarmac routes leading north all the way to Canada and then a trail across Canada. Beats riding across Oklahoma.

    There are routes through Colorado, Utah, and Washington
    http://www.backcountrydiscoveryroutes.com/

    Oregon http://www.oohva.org/

    Idaho (the toughest, many parts are dirtbike only, not for GS riders) http://www.tourofidaho.com/TID.htm

    The Great Divide mountain bike trail which is accessable most of the way by motorcycle http://www.adventurecycling.org/routes/greatdivide.cfm http://www.advrider.com/forums/showthread.php?t=734660 http://www.advrider.com/forums/showthread.php?t=603076

    Once you get to Canada you can hook up with your Commonwealth brothers and sisters to complete the journey east to the Atlantic on the Trans Canada Adventure Route http://advrider.com/forums/showthread.php?t=594395

    That should give the 450 a good test.:lol3
    #46
  7. dakardood

    dakardood Been here awhile

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    Another MONUMENTAL thread begins!!!!!!!!! (and onto 4 pages already) :clap:clap:clap

    Torque and Rally Raid behind it, too! What a combo!!!

    ..and those EVO-2 kits RallyRaid has come up with look the business. Factory look or what?
    #47
  8. Desert Matt

    Desert Matt Been here awhile

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    Jenny, this is a great concept, and if it proves itself reliable, could see huge numbers on the start podium in future years. Good luck. I wish you all all the best in the project. If you bring the road show down under to the safari, I'll be watching closely.
    #48
  9. silentwolf

    silentwolf Been here awhile

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    Fantastic Jenny! :clap

    Just what is needed to keep all us F5ers going until Dakar 2014. Really looking forward to the adventures.
    #49
  10. troy safari carpente

    troy safari carpente Team f5ool

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    Wondered when you were gonna pop the cork on this Jenny... :evil

    So where is the Dr Franken(John)stein resonsible for this little monster...:wink: We want some comment from the mad scientist as well... not only the lab rabbit (hi piglet :wave:lol3)...

    paging ktmmitch to the orange courtesy phone... :ear



    Historical Quote:

    "... orange paint and 37 clicks of suspension adjustment doesn't make up for a shit rider..."


    :evil indeed! :rofl:rofl:rofl
    #50
  11. neduro

    neduro Addict Super Moderator

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    Great idea and look forward to seeing the execution.

    The 450RR has proven itself to be amazingly reliable for what amounts to an uprated motocross engine, but to me, something died with the 450 formula. The days of the Malles Moto rider taking care of the same bike for long periods isn't the same in the new era... which is where your project comes in.

    Will you use any of the good bits off a 690 RR (longer swingarm, etc)?

    :lurk
    #51
  12. doyle

    doyle RallyRaidReview-ing

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    Can't wait to see this unfold.
    #52
  13. Brodovitch

    Brodovitch Team ⌘R

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    Subscribed, this thread looks to be very promising :D

    Can't wait to see the bike at the Hellas Rally in April :clap

    edit: Looks like we will have a common RB holder fitted as well :wink:
    #53
  14. ktmmitch

    ktmmitch Been here awhile

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    Well Troy,I have had to get back in the workshop(lab) after Dakar excitement and now our project is out in the open,it's full steam ahead.
    As it's Jenny's thread i don't want to hijack it,as she can do a much better job explaining the ins & outs of the development than I can(Wellingborough Grammar School has a lot to answer for).
    We hope this concept will prove fruitful,and show people that there is another option than a full-on 30,000 euro rally bike,and hopefully bring a few of the old 690RR bikes, that were outlawed by ASO,back into work.
    It's a little bit of "outback mentality",and there's no guarantee it will work,but it won't be from lack of effort!!
    It may be a bumpy ride,and we're not sure where we are going,but stick along for the ride,it'll definitely be fun.
    Tonight we have the new Tractive Suspension PDS shock arrive,tailor-made to give 300mm rear wheel travel,so we will be trying it on my 690 Enduro at Tuareg in March.This is one of the key company's we will be working with on the LC4-50 project.We want to combine with a small number of highly-skilled,technical suppliers that can aid our development on this project.
    I will be forwarding Jenny all information on engine/technical development as we proceed for her to post up as she feels fit,and Martin (Torque Racing) and I have plenty to do over the next few weeks before Tuareg.

    Little bit of Eye Candy from Holland............................................

    [​IMG][​IMG]
    #54
  15. h2o_snow

    h2o_snow Water, snow & dirt too.

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    +1 I'm In.
    #55
  16. johnBOYhenson

    johnBOYhenson rallye intern

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    subscribed! this is going to be interesting to watch!!!

    Jenny, I love how you generate yourself (and a project) to keep yourself in the Dakar! Very impressive.

    :clap:lol3:evil
    #56
  17. Assfault

    Assfault Exposed Member

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    I can't wait for the hipo 690 piston.
    My bike is getting up there in miles and though it is running great, at some point soon I am going to tear it down and do a top end for it.

    I really don't see riders tearing apart there engines and doing a 450/690 swap as some have mentioned earlier in this thread. Like riding to a race and them switching.
    It entails splitting the cases to change the crank and rod. I don't see that happening from a privateer in a bivouac. I could see and additional engine being used though and switching a complete unit.
    Now where to find another engine???


    Sent from my iPad using Tapatalk HD
    #57
  18. Yellow Pig

    Yellow Pig Allergic to Asphalt!

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    Is it gonna be Carbed or are you gonna tweak the EFI for the 450cc?
    #58
  19. Aussie66

    Aussie66 Been here awhile

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    Got a 690RR in the shed, keep me posted, its either back to rally or convert to ADV bike in which case I dont need a crank or piston.
    #59
  20. JMo (& piglet)

    JMo (& piglet) Gone a bit Baja

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    Hi Assfault! - that's exactly right... as I said in post #35 (maybe I wasn't clear) - a whole new rod and crank will be part of the 450cc 'kit', so if anyone wants the option to swap back and forth between 450 and 690, sourcing a second engine and building that into a 450 would be the way to do it.

    Then it is just a matter of swapping the complete engines over and reprogramming the ECU (or having as second ECU too) - which is what I meant by a couple of hours work? - and I'm not suggesting you'd want to do that in the bivouac or anything, rather than back home/workshop before you leave for the event.

    It's relatively easy to source a secondhand engine these days now the 690 has been in production a few years - the SMC/Duke and Enduros all share basically the same engine.

    However, the real point of this exercise (other than to make the engine Dakar eligible of course) is to create a large oil capacity/low maintenance 450cc engine, that just happens to fit exactly into a great adventure bike chassis, which in turn is also a rather handy rally-bike chassis!

    Of course the 450cc version won't have anything like the same power as the 690cc version, but it will be more than capable of being ridden just the same distances as a regular 690 - which is one of the reasons we want to prove it in Dakar - and once the 450 kit is installed in our race bike/s, I shall be riding them the whole time in 450cc guise to test/prove the longevity.

    Jx
    #60