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alex & i talked a little about this kinda project when i blew the trans on the hawk. it's pretty interesting. i saved an article on it: https://docs.google.com/open?id=0B3_...TkydlBEMDhxR1UQuote:
Originally Posted by Kurlon
edit: I have more info in a spreadsheet if anyone's interested.
As the piston is still seeing compression pressure (just not combustion pressure...) and nothing else has been defeated, the normal means of oiling the cylinder should still function, and the valve train will still be doing it's normal thing so no concerns there.Quote:
Originally Posted by Degsy
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Well, fuel lubes the upper cylinder to a degree but I guess it's negligible and isn't really a concern.
I hadn't considered that, I'd have to defer to those who've built them to see what they've seen for long term survivability of the cripple cylinder. Looks like mid 60s HP is reasonable for these rigs if you just do the injector defeat. I'd imagine you could scavenge some more actually doing the work required to lop off the piston and rod as well as no longer actuating those valves, but you'd also throw the motor out of balance and wreck the cheap 'upgrade' to full MW status down the road.Quote:
Originally Posted by Degsy
Recent thread on WERA about it. Neat project, but not really a good idea for a 'spec' class.
If we're talking a 'spec' class as in Kawi drops off 20 of XXX machine, all identical, LRRS maintained, random rider assignment each weekend, I agree. If we're talking ULThunderbike redone using closer to CCS SS rules, or even PTwins style rules (AKA not a single make/model class), I think it's worth exploring the cost of entry and maint as well as cost of migration up and out at a later date of the different options. Especially when the bike people were initially talking about has just been End of Life'd.Quote:
Originally Posted by a13x
I know you find this really strange Josh but the vast majority of club racers don't want to constantly tinker with their oddball bikes. You do. You revel in it.
End of the day taking a 600cc I4 motor and cutting a cylinder is just too much bother for all but a select few. I'm sure you'll read this and think 'that's absurd! it's so easy!' but it's not. It's a hassle.
Gas. Tires. Go.
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Taking out the rod and piston. Lol. You'd have to weight the crank or something. Not to mention the total loss oil system you'd have unless you welded the valves closed for that cylinder (or maybe ground down 4 can lobes) . I'm gonna try this with an old motor I have lying around.
Heh, while I'm not afraid to tinker, I was MUCH happier once I got my carb and fueling issues sorted on the GS and it was a gas and go mount. That said, yeah, I do like a good oddball.Quote:
Originally Posted by a13x
For any of these classes to take off it's going to require a community. If there is a cripple 600 community similar to what's developed in PTwins, switching in and out of 450 mode will be a matter of showing up with the bike and a six pack on the trailer... walk away for an hour and when you come back it'll be done. :D The same type of community can develop around a 250/300/whatever class too, without that none of these options will turn into anything.
Grinding the lobes off is the theory I've seen bounced around, leave the valves and springs in, toss the bucket/shims. On the crank I dunno as you'd need to leave a weight on or not, I suppose you could make a split bob weight easily enough and then wouldn't have to worry about closing off the oil feed on that rod journal...Quote:
Originally Posted by Degsy
http://www.youtube.com/watch?v=JLVy_zef8Lo
That's one of the most exciting boring races I've watched in awhile. :D (WERA 250 class)