guys Posted January 28, 2017 Report Share Posted January 28, 2017 A side valve! engine. 2 Quote Link to comment Share on other sites More sharing options...
axulsuv Posted January 29, 2017 Report Share Posted January 29, 2017 I hope they continue with the project.... Quote Link to comment Share on other sites More sharing options...
jonnyc21 Posted January 29, 2017 Report Share Posted January 29, 2017 This is something around the 2007/2008 time frame project they stopped and I don't believe they even still have the bike as it was sold in the bankruptcy from what I heard. 1 Quote Link to comment Share on other sites More sharing options...
jonnyc21 Posted January 29, 2017 Report Share Posted January 29, 2017 I agree, it could have been a very nice 4T bike for the clubman rider. From what I understand, they where considering EFI and it was in the 300 to 350cc range. You can hear it sort of wind out a bit at full RPM in the video. Not sure it that's the side valves or just that it's an early prototype and they had not yet optimized the valve and ignition timing etc.. Cool concept nonetheless. Quote Link to comment Share on other sites More sharing options...
breagh Posted January 29, 2017 Report Share Posted January 29, 2017 Imagine it would be good in UK conditions rather than the test conditions with plenty grip. Bit of a waste but at least Gas Gas is still on the go. Hope they invoiced the FIM and Honda for all that work. 2 Quote Link to comment Share on other sites More sharing options...
2stroke4stroke Posted January 29, 2017 Report Share Posted January 29, 2017 Nice one Breagh! Quote Link to comment Share on other sites More sharing options...
dmc2028372 Posted January 29, 2017 Report Share Posted January 29, 2017 If that bike was disposed of when the factory went through I wonder whose collection the bike was 'disposed' into?! 1 Quote Link to comment Share on other sites More sharing options...
trapezeartist Posted January 31, 2017 Report Share Posted January 31, 2017 Brilliant piece of lateral thinking. Modern instinct would naturally think of OHC, yet the side-valve is ideal for trials: light valve train, low engine height, low C of G, revability will be adequate, ditto compression ratio. What's not to like? Quote Link to comment Share on other sites More sharing options...
jonnyc21 Posted January 31, 2017 Report Share Posted January 31, 2017 About the only downside I believe is air flow caricaturists are not optimal for higher RPMs with that design so it would be limited without some work to improve the design to increase flow. Quote Link to comment Share on other sites More sharing options...
trapezeartist Posted January 31, 2017 Report Share Posted January 31, 2017 Agreed, jonnyc21, but side-valve development ended in about 1939. Since then fuels, materials, lubricants and design ideas in general have moved on a long way. I do think there's enough potential in the idea for someone to give it a go. I'd give it a 90% chance of being a success. Quote Link to comment Share on other sites More sharing options...
cascao Posted January 31, 2017 Report Share Posted January 31, 2017 Read somewhere that this project was abandoned due engine having not enough power... Quote Link to comment Share on other sites More sharing options...
guys Posted January 31, 2017 Author Report Share Posted January 31, 2017 A combustion chamber like that is far from ideal in every way, apart from the fact that it saves build height, so it fitted in their frame without much alteration I'd guess. Quote Link to comment Share on other sites More sharing options...
jonnyc21 Posted January 31, 2017 Report Share Posted January 31, 2017 Yes, trapezeartist, it was a long time ago when the development of that tech ended and there is a chance with current advances that it could have worked. I have a lot of speculation in my head about what could improve a side valve design but I am sure many have already considered them all. I suspect I will end up doing some research on the net to see what I can find but ether way we will never know what might have been. Quote Link to comment Share on other sites More sharing options...
trapezeartist Posted January 31, 2017 Report Share Posted January 31, 2017 It looks like there was plenty of thought given to combustion chamber design in the 50s and 60s (http://myweb.tiscali.co.uk/speedex/index_files/Page2476.htm) but this is all backyard development of a pre-war design. Direct injection and stratified charge would open up all sorts of possibilities, though the development costs might be somewhat beyond a company like Gasgas or Beta. It would take Honda to have the resources to play with this stuff, and they wouldn't do it just for trials. Quote Link to comment Share on other sites More sharing options...
axulsuv Posted February 1, 2017 Report Share Posted February 1, 2017 20 hours ago, jonnyc21 said: About the only downside I believe is air flow caricaturists are not optimal for higher RPMs with that design so it would be limited without some work to improve the design to increase flow. When was the last time you went to a cart race ? The Tecumseh / Briggs boys , not the honda clone motors .... They get some evil power out of those engines , and with centrifugal Clutch's , Rpm is a big key ... Quote Link to comment Share on other sites More sharing options...
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