junkyarddog Posted July 11, 2016 Report Share Posted July 11, 2016 Any help would be awesome Let me start off by saying i don't port for money and don't plan to, only trying to learn and make my stuff better I have read a lot on 2 stroke porting online on and off bits and pieces here and there,and have went threw almost, maybe all post in forums online mostly from 1998-2008 and then it seems everything went under ground and top secret, but I'm starting to understand kinda why, when I first started I told any and all, now that I have spent 100's of hours digging and researching when someone ask a question that took me 3 days to find and understand fully and they want it in 15 seconds I'm thinking , wtf I just passed on info that I spent 3 months understanding and finding to this guy in 5 minutes, so now I'm like"read these books online" lol, I got a long ways to go but time is not always on my side when trying to set and read up, here's the deal I ported my cylinders by coping a set about 2 years ago without any know how and using a caliper to measure down from deck but had a steady hand and Iv been a mechanic/ gear head all my life, bike ran better but nothing to brag about, a year later when I got the 1mc I rasied the transfers but now got better bits to smooth up things to flow better then I had then, now I plan to go to the BHQ ride already got my spot payed,and just tore it apart and degreed both cylinders here's the specs Left...EXT 196* TRANS 128* BLOW DOWN 33 , EXT OPEN AT 82. TRANS OPEN AT 114 Right.EXT 195* TRANS 130* BLOW DOWN 32 , EXT OPEN AT 82. TRANS OPEN AT 115 I might be a deg off +or- for chamfer, and also need to chamfer more than I have now, the transfers main,aux,boost ports are all the same heights Also I have invested in fordom sr motor and hand pieces and a 1mc from cc and lots of burrs and still buying burrs, and here is the bikes specs as of right now 64.50 bore wiseco/stock stroke/.020 base/28mm pwk/CPI inframes small bore-also have t5 I swap around/142 main 42 pilot/20cc domes /155 compression?/14-41 gear My thoughts are I need to even everything so both are the same , and stagger my ports by 1/2 mm so that boost opens up first then aux then Main? Thoughts? How can I determine my exhaust port percentage? I paper mapped it and it measures roughly 26mm on flat paper and it's a 64.50 bore Im wanting it around 70-75% from what I have studied How can I improve my exhaust shape? Should I cut the small bit of angle off the sleeve like the other side? Make them both straight down? How's my piston crown look? Hot spot? Quote Link to comment Share on other sites More sharing options...
JTmachining Posted July 11, 2016 Report Share Posted July 11, 2016 I can't help with port specs but ur spot on with why peeps don't share all info lol Quote Link to comment Share on other sites More sharing options...
junkyarddog Posted July 11, 2016 Author Report Share Posted July 11, 2016 Sent from my iPad using Tapatalk Quote Link to comment Share on other sites More sharing options...
junkyarddog Posted July 11, 2016 Author Report Share Posted July 11, 2016 I can't help with port specs but ur spot on with why peeps don't share all info lol Ya and I'm not looking for anyone's hard earned 30 year proven secrets I'm just trying to get advice I can improve on/ learn from and maybe a NO DONT DO THAT there be junk if you do kinda help Sent from my iPad using Tapatalk Quote Link to comment Share on other sites More sharing options...
bigweav81 Posted July 11, 2016 Report Share Posted July 11, 2016 Keep reading, and learning. I'm going to say it must be some what natural instinct to widen the bottom of exhaust. Many do it starting out, including myself. What's your purpose for the bike? Shapes play important roles like angles. Make sure to have domes cut to your specs as well. Sent from my SM-S820L using Tapatalk Quote Link to comment Share on other sites More sharing options...
Larry's Shee Posted July 12, 2016 Report Share Posted July 12, 2016 Ya and I'm not looking for anyone's hard earned 30 year proven secrets I'm just trying to get advice I can improve on/ learn from and maybe a NO DONT DO THAT there be junk if you do kinda help Sent from my iPad using Tapatalk You don't want secrets, but that's exactly what you're looking for, lol. Reread Gorden Jennings, the answer is in there. Short answer is measure straight across ex opening, that's cordial width. Device that into bore Diameter, that's % . I thought mains opened before secondary, secondary before rear boost to aid in evacuating previous charge Quote Link to comment Share on other sites More sharing options...
junkyarddog Posted July 12, 2016 Author Report Share Posted July 12, 2016 Boost port open first to push out spent charge that's what it was designed to help push the charge Out the ext and cool piston crown from what Iv read over the years and Iv looked at that book and many others but hard to retain so much info up stairs with the rest of the stuff that's there and the daily crap and learning about 8 other things so I might be a off a little or a lot who knows? Sent from my iPad using Tapatalk Quote Link to comment Share on other sites More sharing options...
Wildcardracing Posted August 14, 2016 Report Share Posted August 14, 2016 (edited) If you're going to run a staggered transfer arrangement you'll have much better luck opening the primaries first then secondaries and boost last. Make sure you're exhaust crown is not too flat and the ports are perfectly symmetrical. -B Edited August 14, 2016 by Wildcardracing 1 Quote Link to comment Share on other sites More sharing options...
sleeper06 Posted August 14, 2016 Report Share Posted August 14, 2016 Opening boost first is old school, I've done it but don't anym. You want an opinion don't do kinda shit, look at the skirt area where you have boost ports. With that much material any sort of failure and your cylinder will crack there. I've seen it many times on overprted stockers. I've found portiing tunnels too much greatly lower of ability to pull gear at and just after peak power . Making it rev quick and never go anywhere instead of freight training the gear Quote Link to comment Share on other sites More sharing options...
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