rangerboyxlt Posted July 14, 2008 Report Posted July 14, 2008 Just as the title says. How can you tell the difference between the CPI small bore and big bore pipes? any help would be greatly appreciated. Thanks Quote
KaosBanshee44 Posted July 14, 2008 Report Posted July 14, 2008 Big bore pipes are for the larger motors 440cc and up. Anything below that should run the small bore pipes. the exhaust flange on them are different as well if i'm thinking correctly Quote
okbeast Posted July 14, 2008 Report Posted July 14, 2008 They make small flange big bore and small bore pipes, so that's not a good way to tell. I'm not actually sure how to tell, usually the big bores are bigger of course, but hwo much and where i'm not sure. Quote
shanYE west Posted July 14, 2008 Report Posted July 14, 2008 On shearers its bigger just past the flange. Not sure about CPI's Quote
KaosBanshee44 Posted July 14, 2008 Report Posted July 14, 2008 On shearers its bigger just past the flange. Not sure about CPI's Damn that's what i meant to say. The big bore and small bore pipes look almost the same but if you look closely where they come off the jug the small bore pipes are smaller than the big bore. I'm pretty sure they can fit on any jug it's just how wide they come off the jug that matters. I may be corrected by someone since i've only bought toomey pipes and big bore pipes in my lifetime cause i went by the chart. Don't be stupid and get your motor ported and bored and think you need big bore pipes. There's a reason why they made them like anything else. Quote
Snopczynski Posted July 14, 2008 Report Posted July 14, 2008 Damn that's what i meant to say. The big bore and small bore pipes look almost the same but if you look closely where they come off the jug the small bore pipes are smaller than the big bore. I'm pretty sure they can fit on any jug it's just how wide they come off the jug that matters. I may be corrected by someone since i've only bought toomey pipes and big bore pipes in my lifetime cause i went by the chart. Don't be stupid and get your motor ported and bored and think you need big bore pipes. There's a reason why they made them like anything else. Nobody knows this? The outlet diameter on the small bores where the silencer stinger hooks up is smaller than the big bores. Quote
BuckeyeShee21 Posted January 18, 2012 Report Posted January 18, 2012 Dug this post up from the ruins. Does anyone know the diameter of the stinger on a cpi inframe small bore or big bore? Or could possible measure it? I have a set laying around that I want to sell. I think they are big bore, but I want to be positive. Any help would be greatly appreciated. Quote
noslo98 Posted January 22, 2012 Report Posted January 22, 2012 Correct the CPI SB vs. BB the only diference is the stinger size. But the 440 cc rule does not always apply. You need to find what pipe works best for your application. We use BB on most of our 421cc 4mil cubs and have used them on smaller ones as well. I have been testing on my bike this past week and it makes better power with the BB over the SB. Not by much though but if you can get away with BB its a better option since it helps with detonation problems. Quote
BuckeyeShee21 Posted January 25, 2012 Report Posted January 25, 2012 Correct the CPI SB vs. BB the only diference is the stinger size. But the 440 cc rule does not always apply. You need to find what pipe works best for your application. We use BB on most of our 421cc 4mil cubs and have used them on smaller ones as well. I have been testing on my bike this past week and it makes better power with the BB over the SB. Not by much though but if you can get away with BB its a better option since it helps with detonation problems. Yea this post was from 4 years ago, I just dug it up hoping someone could measure their stinger diameter so I knew for sure if mine were big bore because I want to sell them Quote
ban565 Posted January 25, 2012 Report Posted January 25, 2012 the end of the pipes are an 1/8 inch dirrerence. big bores 1 inch id and the small bores are 7/8 inch id. Quote
BuckeyeShee21 Posted January 25, 2012 Report Posted January 25, 2012 the end of the pipes are an 1/8 inch dirrerence. big bores 1 inch id and the small bores are 7/8 inch id. Right on. Thanks. Big bore cpi's on a dune ported stock cylinder motor = absolutly no bottom-mid range power... obviously. Goin up for sale. Quote
2004LEBanshee Posted January 25, 2012 Report Posted January 25, 2012 I already gave you exact measurements 4 days ago. Quote
SonOfSand Posted January 25, 2012 Report Posted January 25, 2012 I already gave you exact measurements 4 days ago. Are the measurements above correct? Quote
BuckeyeShee21 Posted January 25, 2012 Report Posted January 25, 2012 Are the measurements above correct? Yes, they are correct. I had asked the question before LEBanshee gave them to me. Thanks. Quote
2004LEBanshee Posted January 25, 2012 Report Posted January 25, 2012 First your digging up old threads then your not trusting my ability with a digital caliper. Haha jk Quote
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