registered user

aint like a bunch of parts changers would know what they were lookin at anyways. let alone copy it with a walmart dremel. just sayin to duplicate it with any accuracy would require a very detailed blueprint drawing. ive seen a few "professional" shops stuff and it didnt appear much time or thought went into it. definatly not somethin i would want to copy

i assume your intention was drag racing ? it doesnt make much sense to have a big gap above the piston . not that your .045 value wont work but i think youll have better luck alittle smaller. 50% area is a good number. theres a few other things to consider but the good part is blank domes are usually to be pretty cheap. and if you have the machine to do the cutting youll have no problem figuring out a nice combination in a short time

68x64 with 125 rod is that what you were thinking ?

large bore short stroke is not the best idea on a 2t. any builder worth a grain of salt will tell you this. on a twin with cylinders close together the trans tunnels dont have the best of geometry to begin with. increasing the bore only adds to the problem. when they go almost straight up and make a 90* turn thats a poor performing duct small bore cub close to sqaure with as long a rod as possible is likely to have the most power per cc.

so both would be close to 500cc if im thinking right. 68x68 on the cub and 72x58 on the dm ? sqaure engines usually have the advantage with more port area assuming both are close to the same cubic capacity and similar port design. over sqaure is never a good idea if you can avoid it especially if its extremely over sqaure. 72x58 would be extreme imo but you have to remember if the cub is originally cast as 64mmbore and you take it to 68 what is that gonna do to the trans and exh tunnels likewise with 72. when you push the bore that far into the tunnels is not a ideal situation

just pointing out how little most of us understand these engines. myself included.

when you test 200 pipe variations, about the same amount of heads, endless ign curves, every duct has perfect geometry, you have to think what the next step is gonna be. using more bore surface for trans ports seems like a good idea to explore

leave it to a parts changer to compare poppet valve to the cylinder on previous page. he doesnt understand how or why it works so i would expoect that sort of analysis. in a conventional cylinder when the transfer port area becomes the limiting factor what do ya do ?

1 i wouldnt know k&t if i seen em walking down the road. im sure theyre nice folks though 2 wasnt talking about suzuki floor ports. more like a door that opens the intake to the atmoshere 360* 3 not sure who invented stepped exh nor do i care. but they do work and have been used on yz250, cr250, rsa, just to name a few 4 if a performance modder cant be somewhat of a engineer also, then i guess youll never get any faster 5 dont know why you brought up rotory disks 6 aparently we agree to disagree on this. i prefer to learn 2t fundamentals from the guys across the pond

alot of info but im not gonna bother posting it. all the parts changers that dont have a clue how it works will just call it bs

hey check out these scooters. ill bet the farm theres some rsa technology in that motor somewhere

that cylinder with the 360 trans ports has already been cast, there is photos of it as a finished product. and it its on a running engine if i recall although i dont know any exact details of its performance but it was suppose to exceed the rsa. wheres all the new ideas if theres so much real world r&d ? all i see is the same setups from years ago. i asked about a stepped port. anybody tried that ? theres plenty more ideas atleast worth trying. nothing ventured nothing gained. how many guys use a full programable ign ? im not even convinced pipe technology in the usa is on par with what theyre doing in other parts of the world the original question was regarding wether the volume of a trench would cause issues. i dont believe so but whateva. the logical approach would be to increase volume until power drops off, or am i wrong ?

im not gonna even comment on this. youll be stuck spinning your wheels with the same ole setup for eternity. good day sir

pretty soon theyll have variable transfer ports too. then we'll really look stupid. come on guys wake the F up. get some paper and start thinking on ideas before we're 10' deep in shit with no shovel

we need some innovation around here but i dont see it. how about a trap door of sorts that stays full open when the engine is in powerband. fuck we already got beat to the punch by the tuners over seas

banshees are cool and some are damn fast. still not on the level of rsa performance. nor will they ever be. twin cylinders with short strokes it just cant happen. plus theyre reed cylinders and like the other dude said even with spread bore i dont know if you can get the trans ports perfect

wasnt it trenton tingy that said it best. your like a tick on a deer that wont go away lol. no but back to your question. i didnt say anything about banshee tuners over seas. i said the foremost 2t experts were over seas. you can look up jan thiel, the guy behind the aprliia rsa. more world titles than you can shake a stick at, more than anyone else i do believe. and like another guy said that was in the same circle of people, the best cylinder in history. there is a new design recently that is supposed to exceed the rsa performance . i believe it is running but not sure of any power numbers. from what i understand it was destined to be a 125cc but the gp 2t is all but dead so it got scaled down to a 50cc

at the moment i dont have a pic of the rsa manifold but i have another pic that will give you a general idea

what about a stepped exh to the manifold. other engines use it with good sucess. has any usa guys tried it ? i know all the cp jugs are cast round in the exh but maybe someone has welded one up ? in a way i think we are kinda lagging behind. my opologies if someone has attempted it. if someone has gave it a go what was the results ?

do the same laws that govern the rsa trans duct not apply to a banshee ? surely they do. some may learn somethin from that pic. others wont and will continue knifing everything

it all relates across the board. most would see this cylinder and not understand why it is the way it is. first mistake alot of guys do is knife edge everything hahahaha

i dont think it would be so simple to improve the best cylinder in history. surely many have tried and failed. rsa design is copied often for use on other engines

its not about sending your stuff overseas. its about learning from what theyve already figured out and applying it to other engines. riding their coat tails you could call it

that should be fun grindin all that epoxy out

prox site lists dimensions of everything but i dont know if the sizes listed are dead nuts on. they say 26mm for one of my pins but it measures alittle less with digital caliper. caliper could be off alittle and i dont have time to dig out the micrometer. if at all possible your probly better off getting a rod kit to get exact measurements