entropy
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posted April 20, 2009 02:04 AM
 Edited By: entropy on 20 Apr 2009 10:05
Warning - measuring bearings with boregauge...
yesterday i was measuring up bearings & rods in prep for 2009 build #4.
arithmetic wasn't adding up
rod big end ID - bearing thickness - rod journal OD = clearance yes?
But when i used a boregauge & checked the ID's of bearings in 2 tq-ed rods they were .0008 and .0009 larger than the calculated method. A bell was ringing in my head but i didn't listen to it.
Later on Sunday Tim Chin reminded me of a discussion we had had more than a year ago about the the same issue, and the likelihood that the boregauge was digging into the bearing material. He suggested retaking the mounted/tq-ed bearing ID with a snap gauge.
This morning i used the snap gauge and the measurement was within a tenth to the calculated method.
just a heads up...
Thanks Tim!!!!!!! 
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psycho1122
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posted April 20, 2009 05:20 AM
No....Thank You Karl!!
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tcchin
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posted April 20, 2009 07:24 AM
Thanks for the update, Karlos. Thank God math still works! My world makes sense again.
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entropy
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posted April 20, 2009 07:42 AM
quote:
Thanks for the update, Karlos. Thank God math still works! My world makes sense again.
If my memory gets any worse they'll soon be tying to the big mango tree in the rain.
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KZScott
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posted April 20, 2009 01:17 PM
very interesting. thx for the tip!
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01 ZX-12R 8.84 @ 156.3 no bars, DOT tires. Pump Gas, NA.... turbo 8.47 @ 164.
00 ZX-12R 8.62 @ 165.2 no bars, slicks, Pump Gas, 55 shot.... turbo 8.32 @173
00 ZX-12R Fastest NA Kawasaki in the world 1: 222.046 1.5: 226.390 Loring AFB
00 ZX-12R street turbo 1: 227.9 1.5: 234.1 Loring AFB
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brendasue555
Expert Class
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posted April 20, 2009 01:24 PM
Is that what this thing is that I am tied to?
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Brenda
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osti33
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Posts: 2973
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posted April 20, 2009 01:37 PM
I thought snap gauges measured OD not ID?? I'm so confused(doesn't take much). Are you talking about a telescoping gauge or is their some other kind of snap gauge I don't know about(probably)?
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entropy
Moderator
Posts: 8671
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posted April 20, 2009 01:52 PM
quote:
I thought snap gauges measured OD not ID?? I'm so confused(doesn't take much). Are you talking about a telescoping gauge or is their some other kind of snap gauge I don't know about(probably)?
telescoping gauge, prob not a snap gauge.
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entropy
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posted April 20, 2009 01:53 PM
quote:
Is that what this thing is that I am tied to?
PIX, please!
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osti33
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posted April 20, 2009 02:01 PM
Edited By: osti33 on 20 Apr 2009 22:02
Telescoping gauges. Here is a pic I found with a quick google search. I just want to make sure we are on the same page. You use these guys then lock them, take em out and measure with an OD mic. Sound right?
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tcchin
Zone Head
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posted April 20, 2009 03:15 PM
Yup. I just assumed that "snap gauge" was some kinda Texas slang for "telescoping bore gauge."
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osti33
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posted April 20, 2009 03:21 PM
Edited By: osti33 on 20 Apr 2009 23:22
quote:
Yup. I just assumed that "snap gauge" was some kinda Texas slang for "telescoping bore gauge."
Ok. I got it now.
"Texas slang".
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KZScott
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posted April 20, 2009 03:58 PM
quote:
quote:
Is that what this thing is that I am tied to?
PIX, please!
is anyone else thinking pink handcuffs? 
____________
01 ZX-12R 8.84 @ 156.3 no bars, DOT tires. Pump Gas, NA.... turbo 8.47 @ 164.
00 ZX-12R 8.62 @ 165.2 no bars, slicks, Pump Gas, 55 shot.... turbo 8.32 @173
00 ZX-12R Fastest NA Kawasaki in the world 1: 222.046 1.5: 226.390 Loring AFB
00 ZX-12R street turbo 1: 227.9 1.5: 234.1 Loring AFB
00 ZX-12R LSR turbo 1: 263.1 1.5: 266.5 Loring AFB Worlds fastest ZX-12R
CMG Racing RCC Turbos
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krexken
Zone Head
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posted April 20, 2009 06:33 PM
I calls em snap gauges also. Sounds like your bore gauge needs some bigger, less pointy contact surfaces. Some are removeable. A few of our dial indicators at work come with a variety of ends.
On another note, I remember when you farmed out pretty much all of your motor work, Karl. I'm so proud you do your own now. (sniff, sniff)
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entropy
Moderator
Posts: 8671
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posted April 20, 2009 10:00 PM
quote:
quote:
quote:
Is that what this thing is that I am tied to?
PIX, please!
is anyone else thinking pink handcuffs?
busted!
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entropy
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posted April 20, 2009 10:07 PM
quote:
I calls em snap gauges also. Sounds like your bore gauge needs some bigger, less pointy contact surfaces. Some are removeable. A few of our dial indicators at work come with a variety of ends.
On another note, I remember when you farmed out pretty much all of your motor work, Karl. I'm so proud you do your own now. (sniff, sniff)
hey Ken, good to see you are lurking back there!!!
yup, i need to fix my bore gauge up with some big balls.
We did have a ton o' fun at HRP when the Texas Shootout was operating; breaking parts was sure part of it.
The silver lining in JohnnyCheese closing the batcave for a couple years was that it forced me into building my own motors. a l-o-n-g road to learning this stuff.
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tcchin
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posted April 20, 2009 10:30 PM
Edited By: tcchin on 21 Apr 2009 06:31
quote:
yup, i need to fix my bore gauge up with some big balls.
Of course, since you can trust the math now, you can just use a micrometer to measure the bearing shells and your as-is bore gauge to measure the bare rods. Or you can use the telescoping bore gauges and a micrometer to measure the assembly. I haven't been able to find replacement contact points for Mitutoyo or Fowler bore gauges. Mitutoyo makes a nice digital micrometer style bore gauge, but it has three contact points instead of two. Since I measure all of my bearing shells anyway, and since my rod bolts are non-reusable, I'm going to continue to use the "math method" and forego measuring the assemblies.
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NINJA12
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posted April 21, 2009 04:57 AM
Tcchin, have you noticed any difference in you numbers when the rod are torqued to less than full stretch? When using a number like 20 lbs in place of 17 + 120 degrees.
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tcchin
Zone Head
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posted April 21, 2009 08:02 AM
Yes, about a thousandth. The big end actually deforms slightly under full torque, at least on a GSX-R1000 stock rod.
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chavcat
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posted April 21, 2009 03:48 PM
Tim/ Karl - Do you measure several areas of each bearing shell with the micrometer or a single area trusting the shell is uniform thickness?
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tcchin
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posted April 21, 2009 04:05 PM
The shells are typically thicker in the middle, and the good ones are of uniform thickness across the width. I usually measure between three and six points near the middle of each shell, just to be sure I know what's going on. Any shell that varies across its width by more than .003mm will get marked and stored as a backup part. Often times, you can see where the factory took its thickness reading, as there will be a shiny line across the bearing shell.
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chavcat
Zone Head
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posted April 21, 2009 05:13 PM
Thanks. Do you use a standard micrometer or a specialized tip given the radius of the shell?
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TRNorBRN6001
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posted April 21, 2009 05:31 PM
Magic rubber tip thing, but that's between Karl and the Garage Barbies
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tcchin
Zone Head
Posts: 867
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posted April 21, 2009 05:51 PM
I use an adapter from McMaster-Carr (#2313A12).
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chavcat
Zone Head
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posted April 21, 2009 06:37 PM
Where is a good place to purchase this adapter?
Thanks
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