registered user Posted March 9, 2013 Report Share Posted March 9, 2013 anyone tried cutting the intake bridge out ? Quote Link to comment Share on other sites More sharing options...
apeik Posted March 9, 2013 Report Share Posted March 9, 2013 Can you hear the rings catching? Quote Link to comment Share on other sites More sharing options...
turbowrenchhead Posted March 9, 2013 Report Share Posted March 9, 2013 anyone tried cutting the intake bridge out ? Yeah, you don't want to do that. I would say it needs to be at least 1/8 wide. Chime in if I'm wrong Quote Link to comment Share on other sites More sharing options...
sheerider11 Posted March 9, 2013 Report Share Posted March 9, 2013 Yeah, you don't want to do that. I would say it needs to be at least 1/8 wide. Chime in if I'm wrong I feel like that would be to big of an area for the piston to basically fall into. Imagine you had a little to much piston to wall clearance. I feel like the bottom could catch in there. I also feel like the intake and exhaust both being that open, the piston could damn near get cocked into both ports Quote Link to comment Share on other sites More sharing options...
registered user Posted March 9, 2013 Report Share Posted March 9, 2013 anybody got a set of stock cylinder sitting around to measure the intake port width ? if its around 65% of bore, you should be able to cut out the bridge with no problem. ideally the best design is a intake port with no divider Quote Link to comment Share on other sites More sharing options...
registered user Posted March 9, 2013 Report Share Posted March 9, 2013 on alot of cylinders i think the bridge is there mainly to add support for the cylinder skirt. plus with the bridge gone you would probly gain as much or more intake area as adding boyesen ports. just a thought i had. by no meens am i a banshee expert. never even had a banshee in my hands actually. Quote Link to comment Share on other sites More sharing options...
Colby Posted March 11, 2013 Report Share Posted March 11, 2013 on alot of cylinders i think the bridge is there mainly to add support for the cylinder skirt. plus with the bridge gone you would probly gain as much or more intake area as adding boyesen ports. just a thought i had. by no meens am i a banshee expert. never even had a banshee in my hands actually. few years ago i read about an experiment where the bridge was removed, intake area was GREATLY improved, and if i recall, the person could make up the area w/ a single exhaust port to compensate ... nevertheless, i think i remember his only gettting around an hour out of a top-end ... could have just been this person did not know what he/she was doing. Quote Link to comment Share on other sites More sharing options...
Colby Posted March 11, 2013 Report Share Posted March 11, 2013 Now on banshees I don't think polishing in necessary?? a mirror finish is unneccesary, but the smoother the better Quote Link to comment Share on other sites More sharing options...
registered user Posted March 11, 2013 Report Share Posted March 11, 2013 has to be a reason nobody cuts out the bridge. maybe it would crack the piston skirt ? Quote Link to comment Share on other sites More sharing options...
sprinklerman Posted March 11, 2013 Report Share Posted March 11, 2013 has to be a reason nobody cuts out the bridge. maybe it would crack the piston skirt ? I'm going to go out on a limb here and say that for a great majority of the builds out there,that the Time/Area of the intakes (with the bridge intact) is sufficient for the engine package. So there's really no reason to cut it out. Quote Link to comment Share on other sites More sharing options...
registered user Posted March 11, 2013 Report Share Posted March 11, 2013 I'm going to go out on a limb here and say that for a great majority of the builds out there,that the Time/Area of the intakes (with the bridge intact) is sufficient for the engine package. So there's really no reason to cut it out.. i was wondering about that also. it makes perfect sense ive seen a few guys that really enlarge the 2 windows and thin out the bridge. like pasi on page 8. i was just wondering if rather than enlarging the windows, maybe you could remove the bridge and get the same amount of area, and youll have the added benefit of the bridge not being in the flow path. but i supppose that leaves a greater risk of piston cracks Quote Link to comment Share on other sites More sharing options...
registered user Posted March 16, 2013 Report Share Posted March 16, 2013 anybody know much about the stepped exh port ? they were doing it on some of the 250cc mx engines and maybe some of the GP 125cc ? figured somebody may have welded a step into a stock cylinder to see how it ran ? camatv seems like your always trying new stuff. ever give it a thought ? Quote Link to comment Share on other sites More sharing options...
registered user Posted March 16, 2013 Report Share Posted March 16, 2013 Quote Link to comment Share on other sites More sharing options...
trickedcarbine Posted March 16, 2013 Report Share Posted March 16, 2013 Bizzare shit on that last one. Need to port in to the case as well? This one is pretty unique as well.... Quote Link to comment Share on other sites More sharing options...
camatv Posted March 16, 2013 Report Share Posted March 16, 2013 stepped exhaust.. i dont know on that one... gp stuff was always trying all kinds of 0ff the wall stuff to get an edge. i miss reading about those trials if the charge coming from the pipe is hitting that "step" i'm sure its causing a huge velocity change and turbulence issue. i would think that unless the exhaust flange, first section of the pipe is not the same shape probably wouldnt work very well.. UNLESS they were doing it on purpose to try to remix the last intake fresh charge with the backpush from the exhaust..?? on a side not. the older aircooled rd's had no bridge in the intake. yamaha redesigned them with the intake bridge to help with piston life. i personally leave the bridge as wide as stock and do work around that. after trying a lot of different things its obvious to me there is a lot of stress in that area and it dosnet take long for thin stuff to cause cracks.. on the boost ports i have some of my own therories on how to shape them and where to point them. tried it on the lil 350cc that i welded up and to me the motor feels like it comes on stronger off the bottom and the pipe hit is much smoother. i feel that the intake charge isnt haveing to take so many motion or flow turns to get into the transfer area. those cyls with the added transfers on the intake i have seen them also. ran something similar to that in the old mx days. i dont know if they really added anything or just caused the cylinders to crack over time.. with what i know now from all the differnt stuff i have tried i would love to build another MX motor. but with the 4 strokes dominating that it would be difficult to do.. on the polished exhaust i personally do not do that. i found that the smother surface actually promoted carbon buildup and the roughter i made it the better it stayed clean.. of course thats oppisite what the internet say so is but i dont care. its what i figured out on my personal motors. to me you can learn a lot with time as much as performance. the longer life cycle of the engine the more hours and the more ride time you have in the same motor the more you can see certain patterns emerge. Quote Link to comment Share on other sites More sharing options...
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