garage19 Posted January 14, 2009 Report Share Posted January 14, 2009 Was chatting with a mate the other day and both thought it would be great to build a 2 stroke 500 or 1000 cc V twin engine. The idea would be to use a pair of existing top ends (heads, barrels, pistons and maybe rods) from a CR250 or 500 mated to custom crankcases with a custom crank. You could use the gearset/ primary drive and clutch from another motorbike eg R6. For one or two engines it would probably be best to get the crankcases machined from billet rather than cast and then machined. Only thing we weren’t sure on is the firing order. As far as we figured both cylinders would have to fire at the same time due to the crankcase charge. Is this how the Honda GP500 twins were? I suppose this looses the natural balancing of a 90 degree twin? Any thoughts? Link to comment Share on other sites More sharing options...
wavydavy Posted January 14, 2009 Report Share Posted January 14, 2009 Only thing we weren’t sure on is the firing order. As far as we figured both cylinders would have to fire at the same time due to the crankcase charge. Is this how the Honda GP500 twins were? I suppose this looses the natural balancing of a 90 degree twin? Each cylinder's portion of the crank is sealed off from the others' in two stroke multis using a single crank as, other wise, you'd have no guarantee of an even mixture ever getting to each cylinder. I shall find some images to show what I mean.... Dave Link to comment Share on other sites More sharing options...
Liamo Posted January 14, 2009 Report Share Posted January 14, 2009 Was chatting with a mate the other day and both thought it would be great to build a 2 stroke 500 or 1000 cc V twin engine. The idea would be to use a pair of existing top ends (heads, barrels, pistons and maybe rods) from a CR250 or 500 mated to custom crankcases with a custom crank. You could use the gearset/ primary drive and clutch from another motorbike eg R6. For one or two engines it would probably be best to get the crankcases machined from billet rather than cast and then machined. Only thing we weren’t sure on is the firing order. As far as we figured both cylinders would have to fire at the same time due to the crankcase charge. Is this how the Honda GP500 twins were? I suppose this looses the natural balancing of a 90 degree twin? Any thoughts? You can get custom made crankcases to take 2 CR500 barrels and have yourself the king of paralell twin strokers. A crazy frenchman named Seb is building one to go into a 996 frame. Fucking legend Link to comment Share on other sites More sharing options...
garage19 Posted January 14, 2009 Author Report Share Posted January 14, 2009 We figured that's what would be needed but couldn't figure how it was done. Pics would be great thanks. Link to comment Share on other sites More sharing options...
Liamo Posted January 14, 2009 Report Share Posted January 14, 2009 We figured that's what would be needed but couldn't figure how it was done. Pics would be great thanks. i'll have a butchers when I get a chance man, google is your friend!! Link to comment Share on other sites More sharing options...
wavydavy Posted January 14, 2009 Report Share Posted January 14, 2009 NS400 lower crank case, with crank in situ - note large bearings inbetween each conrod/crankweight assembly...: NS upper crankcase, showing where those big bearings/seal sit, thus keeping each cylinder separately sealed from the others: This should help with getting your head(s) round the idea of sealing each cylinder off separately so you can have *any* firing order you want. It's worth noting the positioning of the 3 NS conrods, remembering that is a 90-degree V3. Dave Link to comment Share on other sites More sharing options...
Liamo Posted January 14, 2009 Report Share Posted January 14, 2009 It's worth noting the positioning of the 3 NS conrods, remembering that is a 90-degree V3. Dave fronts fire as a pair? Link to comment Share on other sites More sharing options...
David W Posted January 14, 2009 Report Share Posted January 14, 2009 When is someone going to get a pair of RGV250 engines in the same crankcases? And can I have one when they've done it please? Link to comment Share on other sites More sharing options...
wavydavy Posted January 14, 2009 Report Share Posted January 14, 2009 When is someone going to get a pair of RGV250 engines in the same crankcases? And can I have one when they've done it please? As mentioned a while back, I proposed it as a project to PB a few years back (but with RS250s taken out to 300cc as (1) RS250s carried on longer and so newer ones could be sourced and (2) 2 x 300cc could be a softer state of tune for good power..). Not same cases, but two motors mated togethr through one clutch and gearbox - if that mentalist bloke can make 8-cylinder KHs (and. of course, PB featured an RD750 made from two 350LCs back in the day) then you can do it with two V2s.... I offered to pay for it all if they found someone who'd do it.... Didn't even get a reply... Dave Link to comment Share on other sites More sharing options...
wavydavy Posted January 14, 2009 Report Share Posted January 14, 2009 fronts fire as a pair? And the middle one just after (or is it before, I forget.... ) - "Big Bang" stroker *years* before GP500s did it.... Dave Link to comment Share on other sites More sharing options...
David W Posted January 14, 2009 Report Share Posted January 14, 2009 I remember the RD700. I guess the principal is the same but it was about 4ft wide! Link to comment Share on other sites More sharing options...
Ninja & B King Boy Posted January 14, 2009 Report Share Posted January 14, 2009 what about what these guys are doing with thier 500 twin it makes 112 BHP and 60 max torque in an RS 250 bike. http://www.twostrokeshop.com/index.htm the only problem is they are down in OZ. Link to comment Share on other sites More sharing options...
nzknut Posted January 15, 2009 Report Share Posted January 15, 2009 you know what this makes me thing of? A two stroke britten. that would be mega. Link to comment Share on other sites More sharing options...
Liamo Posted January 15, 2009 Report Share Posted January 15, 2009 what about what these guys are doing with thier 500 twin it makes 112 BHP and 60 max torque in an RS 250 bike. http://www.twostrokeshop.com/index.htm the only problem is they are down in OZ. In think Steve who owns the Two Stroke Shop is a member on here, but I could have imagined that. Link to comment Share on other sites More sharing options...
chris675 Posted January 15, 2009 Report Share Posted January 15, 2009 has anyone on here got one of those engines? Link to comment Share on other sites More sharing options...
wavydavy Posted January 15, 2009 Report Share Posted January 15, 2009 has anyone on here got one of those engines? One of what engines - a fair few have been mentioned here... You might want to quote posts when replying to keep context. Oh, welcome to ! Dave Link to comment Share on other sites More sharing options...
rc30rob Posted January 16, 2009 Report Share Posted January 16, 2009 i know a man who could possibly do something like this what about a v6 750 2t using Rg parts and what chassis Link to comment Share on other sites More sharing options...
GREENGOATCHOKER Posted January 16, 2009 Report Share Posted January 16, 2009 When is someone going to get a pair of RGV250 engines in the same crankcases? And can I have one when they've done it please? crank cases are done barrles are being bored to 150cc a piece , cougar heads and powervalves hoping for 140bhp at the wheel .................... we will see Link to comment Share on other sites More sharing options...
alexp5 Posted January 16, 2009 Report Share Posted January 16, 2009 You need to check out Alan Millyards creations. Google him. His builds have been in Classic & Motorcycle Mech's in the past. Any one fancy a 2.6 litre V12 Z1300??? Also does wierd stuff to Kwak 2-squeeks. Link to comment Share on other sites More sharing options...
wavydavy Posted January 16, 2009 Report Share Posted January 16, 2009 that mentalist bloke can make 8-cylinder KHs You need to check out Alan Millyards creations. That's the fella! Dave Link to comment Share on other sites More sharing options...
wavydavy Posted January 16, 2009 Report Share Posted January 16, 2009 crank cases are done barrles are being bored to 150cc a piece , cougar heads and powervalves hoping for 140bhp at the wheel .................... we will see Is this the new super-duper secret project???? I hope someone from the mag is reading this! We need details and pictures and more pictures and more details and I want a go and I want it all *NOW*!!!! Dave Link to comment Share on other sites More sharing options...
Ray Von Posted January 16, 2009 Report Share Posted January 16, 2009 Maybe someone should take a look at snowmobile engine, 700cc twin two stroke, only thing is sourcing a gearbox for it and it runs direct drive. Link to comment Share on other sites More sharing options...
willbloke Posted January 16, 2009 Report Share Posted January 16, 2009 A crazy frenchman named Seb is building one to go into a 996 frame. Fucking legend Is that the Seb who used to build big-bore RD sleepers and scare R1 owners on track days ? Blokes a nutter ! Link to comment Share on other sites More sharing options...
Liamo Posted January 16, 2009 Report Share Posted January 16, 2009 Is that the Seb who used to build big-bore RD sleepers and scare R1 owners on track days ? Blokes a nutter ! Sounds like something he'd do alright, he has tuned RD engines in everything! Link to comment Share on other sites More sharing options...
alexp5 Posted January 16, 2009 Report Share Posted January 16, 2009 That's the fella! Dave Simon Whitlock is another crazy fruit... http://www.bigbikeriders.com/48cyl.htm Link to comment Share on other sites More sharing options...
willbloke Posted January 16, 2009 Report Share Posted January 16, 2009 Lets not forget one of my bikes big brother ... From this To this Many many cylinders edit : bugger , beaten to the punch Link to comment Share on other sites More sharing options...
willbloke Posted January 16, 2009 Report Share Posted January 16, 2009 Maybe someone should take a look at snowmobile engine, 700cc twin two stroke, only thing is sourcing a gearbox for it and it runs direct drive. That's another thought , Yamaha make/made a wetbike with a 1000cc stroker triple , just weld it to an R1 gearbox and Roberts yer mothers brother .. Link to comment Share on other sites More sharing options...
garage19 Posted January 16, 2009 Author Report Share Posted January 16, 2009 crank cases are done barrles are being bored to 150cc a piece , cougar heads and powervalves hoping for 140bhp at the wheel .................... we will see I so need pictures of those crank cases. Engineering like that gets me going! Link to comment Share on other sites More sharing options...
speedzephyr Posted January 18, 2009 Report Share Posted January 18, 2009 That's another thought , Yamaha make/made a wetbike with a 1000cc stroker triple , just weld it to an R1 gearbox and Roberts yer mothers brother .. Actually they went up to 1300cc triples, with servo ypvs! If your gonna go, go big. i'd bolt two of em together connected with a gear drive. With pipes it wouldn't fit in a bike....but it would fit in a small car! rated from the factory at 160hp, a tuned pair with proper pipes would probably reach +400hp. Link to comment Share on other sites More sharing options...
GREENGOATCHOKER Posted January 19, 2009 Report Share Posted January 19, 2009 These aren't mine but they are a set made to house two cr500 barrels . Link to comment Share on other sites More sharing options...
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