Bored Cylinders
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Cruiser
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Bored Cylinders
I bought some bored out cylinders on Ebay that were supposed to be 3.875", then the guy told me that they were +.010 over. I told him ok because I hadnt bought my pistons yet. I measured the cylinders last night and they are measuring out 3.883" and 3.881". What is the acceptable amount allowed? I am afraid that these wont work. If not it would still be cheaper to by pistons and send them with my cyls to be bored and sell the ones I got on ebay. I could also send them out and make it a 98". I used some digital calipers I borrowed from work, what would be a better way to measure these? Thanks.
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From: san antonio
I bought some bored out cylinders on Ebay that were supposed to be 3.875", then the guy told me that they were +.010 over. I told him ok because I hadnt bought my pistons yet. I measured the cylinders last night and they are measuring out 3.883" and 3.881". What is the acceptable amount allowed? I am afraid that these wont work. If not it would still be cheaper to by pistons and send them with my cyls to be bored and sell the ones I got on ebay. I could also send them out and make it a 98". I used some digital calipers I borrowed from work, what would be a better way to measure these? Thanks.
In your situation, if you want to run forged pistons, you could buy a set of JE pistons and have a "qualified" machinist hone the cylinders to fit those pistons. I happen to prefer cast pistons but I don't think anyone makes cast pistons for a 3.932" (98" bore). Or, you could have the machinist verify the bore and buy a set of SE flat top pistons, .020" over size and have the cylinders honed to fit.
Just a tip for future reference, it's not real smart to buy a set of cylinders before buying pistons, particularly off Ebay. Good luck.
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From: Ashland Ohio
You can send them to Hillside or Hyperformace and they can bore them and fit with 3.932 pistons and that will make you a 98. .... of course you could have done this with the cylinders you have on the bike already... bore to a 95 or a 98 piston. Cylinders are cheap. Hope you didn't pay too much.
Last edited by wurk_truk; Dec 19, 2010 at 05:52 PM.
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Cruiser
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I agree 100%, but for 100 bucks, it was worth a chance. I did my research 1st and found that this company was very reputable and has done a few magazine articles and alot of people here have used them. $133 with shipping.
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I bought some bored out cylinders on Ebay that were supposed to be 3.875", then the guy told me that they were +.010 over. I told him ok because I hadnt bought my pistons yet. I measured the cylinders last night and they are measuring out 3.883" and 3.881". What is the acceptable amount allowed? I am afraid that these wont work. If not it would still be cheaper to by pistons and send them with my cyls to be bored and sell the ones I got on ebay. I could also send them out and make it a 98". I used some digital calipers I borrowed from work, what would be a better way to measure these? Thanks.
Micrometers are needed, as well as a dial bore guage, to set them up correctly.
Scott
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All, my Diamond cut 103 CI juggs with installed 10:5:1 CP pistons are still up for grabs. Someone needs a good Christmas present.
BD
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Not only do you need inside micrometers to measure cylinder bore. HD jugs have to be in torque plates and torgued to spec before you will get a correct measurement. At least that is true fore EVO and TC jugs. Some places like nrhsp will fit pistons to your cylinders if you need help.
http://www.nrhsperformance.com/tech_squish.shtml
http://www.nrhsperformance.com/tech_squish.shtml
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HDF Community Team
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From: san antonio
See #3; not just HD jugs.
