registered user Posted December 31, 2014 Author Report Share Posted December 31, 2014 im sure ive mentioned it before but take a look at calvins cylinders. his dividers arent just a randowm design he pulled out of his ass. he knew what works Quote Link to comment Share on other sites More sharing options...
Deadbeat Posted December 31, 2014 Report Share Posted December 31, 2014 leave it flat and drill holes into the bridge..a bigger port without going bigger...badda-boom badda-bing..pay me bitch Quote Link to comment Share on other sites More sharing options...
Deadbeat Posted December 31, 2014 Report Share Posted December 31, 2014 registered user right now^ Quote Link to comment Share on other sites More sharing options...
registered user Posted December 31, 2014 Author Report Share Posted December 31, 2014 zillafreek probly has some food stamps i bet he would buy that idea Quote Link to comment Share on other sites More sharing options...
sprinklerman Posted December 31, 2014 Report Share Posted December 31, 2014 Comparing an aftermarket cyl that can flow substantially more a/f mix to stock cyl isn't really a good comparison. You can get pretty impressive hp out of stock cyls with untouched intakes. Shows how choked the rest if the cyl is...even when worked over Quote Link to comment Share on other sites More sharing options...
registered user Posted December 31, 2014 Author Report Share Posted December 31, 2014 we arent comparing cylinders. only the divider. calvin could have used any shape but he knew a traditional V like the pics i shown is no good. is there any youtube vids of these impressive engines with no intake work ? Quote Link to comment Share on other sites More sharing options...
sprinklerman Posted December 31, 2014 Report Share Posted December 31, 2014 If the rest of the cyl can't support the intake mods, of what benefit is there to improving it? Quote Link to comment Share on other sites More sharing options...
Dixie normus Posted December 31, 2014 Report Share Posted December 31, 2014 Transfer tunnels are the bottleneck of an oem cyl in my opinion Quote Link to comment Share on other sites More sharing options...
camatv Posted December 31, 2014 Report Share Posted December 31, 2014 yes they are.. hell i have been thinking of completley milling them off and making them much bigger.. after the weld on the lil stockers i did there really was almost none of the original cylinder wall left in there anyways. sprinkles. my lil 350cc has stock sized intake windows in it. i did more with the so called boost ports. if you look at your v pics up there an then think about the cylinders shape and what you are really trying to do ( FEED the transfer NOT the bottom of the piston....) but no matter what i also agree the power is not in the intake so much as everywhere else.. im not trying to state anything bad about where these cap cyls are coming from its just really old school thought on how to do a high rev port.. and the ole D port was the bomb in the late 70's and 80's. it made super pipey stuff and bikes felt WOW bad ass because of the monster "hit" they had.. when lil ole constant power makers just motor'd right on by. Quote Link to comment Share on other sites More sharing options...
registered user Posted December 31, 2014 Author Report Share Posted December 31, 2014 i dont think theres been a engine made after 1982 that doesnt have boyesens. well except banshee and blaster Quote Link to comment Share on other sites More sharing options...
Atomic Monkey Posted December 31, 2014 Report Share Posted December 31, 2014 i dont think theres been a engine made after 1982 that doesnt have boyesens. well except banshee and blaster My '92 wr... no "Boyesens". Now since I'm fairly new to the tech side of 2 strokes and since we're talking intakes... what's the deal with the case induced engines? Quote Link to comment Share on other sites More sharing options...
registered user Posted December 31, 2014 Author Report Share Posted December 31, 2014 in all due respect , wasnt the wr just a '87 490 ? more or less lol case reeds is just a inlet hole right to the crankshaft area. piston is fully supported up above so theres no need for bridges or boyesens Quote Link to comment Share on other sites More sharing options...
sprinklerman Posted December 31, 2014 Report Share Posted December 31, 2014 My deal is this registered user...you come on here calling people "parts changers" and saying things like "don't ever do this" (knife edge) ... but you can't even wrap your head around why a certain piston pin height is preferred? You dwell on minor stuff ( whether an intake port has a knife edge or not...which isn't going to make any HP difference one way or the other btw) but can't comprehend which piston and rod combo has been proven to work for years? ...which btw, has proven to be dependable and been part of engine packages that produce in excess of 120+ hp. ...but good lord!!!.. Don't dare put a point on that intake bridge! FFS. You strike me as someone who THINKS he knows more than everyone else on here ( who btw, have ACTUALLY OWNED and BUILT many fast banshees), when you have yet to do so yourself. Seems odd to me. 4 Quote Link to comment Share on other sites More sharing options...
Dixie normus Posted December 31, 2014 Report Share Posted December 31, 2014 Lesson learned! Class dismissed!! Time for someone to go home and do their homework Quote Link to comment Share on other sites More sharing options...
tfaith08 Posted December 31, 2014 Report Share Posted December 31, 2014 No need to have done anything at all before you begin to wrap your head around theory. I know there were times between builds when I was just dying to talk about porting and I didn't have a soul around. My vote is to give respect to the sake of the topic (RU, you aren't helping by screwing with Zilla). I'm with Cam on this one. Your main goal should be to feed the transfers in whatever way possible. If the V design helps, go for it. I personally think that bore and stroke have a lot to do with it. A V shape is pretty useless when you have a bore that's knocking on 90mm or so, especially when you have boyesens. That charge is very unlikely to see an uninterrupted path to the transfers from the intake windows with the piston flying upwards. A 50mm bore would be a little different IMO. Then again, I'm with sprinkle. I've never been able to detect a difference on the ass-dyno. The bunches of little gems that result in another 5hp in the end will never be discovered without a dyno. IMO, feed the middle of the crankcase and try to avoid a low pressure spot behind the sleeve so that the charge doesn't try to revert and fill that spot. D shape ftw. As for the steeply angled boost port, I'd stick with that the angle because a significant amount of time is spent trying to get the charge up and over the piston. That design is meant to force the charge upward. I DO NOT think that it needs a sharp divier or transition. It should be smooth. Quote Link to comment Share on other sites More sharing options...
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