Maintenance & Technical > KX500 Original
Torque wrench
martinfan30:
The lapping in idea is a good one. Just as I was scraping the gasket off with a razor blade, I noticed high spots around each head bolt hole....
Using crows feet will reduce the torque, just like using an extension, so i always add a few ft. pounds to the mix to compensate.
BDI:
--- Quote from: martinfan30 on March 11, 2009, 02:48:19 PM ---The lapping in idea is a good one. Just as I was scraping the gasket off with a razor blade, I noticed high spots around each head bolt hole....
Using crows feet will reduce the torque, just like using an extension, so i always add a few ft. pounds to the mix to compensate.
--- End quote ---
Laping is a must but it has to be done correctly. As for the crows foot thing I'm not so sure, if the crows foot has an offset of one inch then it's going to add one inch to the length of your wrench if it stuck strait out the front. It would add one inch pound to every foot pound you torqued the bolt too do to the added length. Now if you 180 the crows foot it would subtract one inch pound per foot pound. Now maybe if it was 90 degrees to the wrench head the torque would be correct because you wouldn't be adding or subtracting any length to the wrench. Now you have to figure out how much torque you are losing to jaw spread if you are using an open end style crows foot. If you are using a boxed end style crows foot the torque loss would be a lot less do to the fact you have no jaw spread. Now if you are using an extension it's going to flex and subtract torque, so maybe if you had the crows foot sticking strait out the front and using an extension,the flex of the extension would make up for the added length of of the crows foot and you would wind up back at the proper torque value. I don't think you would though do to the fact that there are still more variables to consider. For example: Are You torqueing your base nuts on wet or dry???
martinfan30:
--- Quote from: BDI on March 11, 2009, 04:26:02 PM ---
--- Quote from: martinfan30 on March 11, 2009, 02:48:19 PM ---The lapping in idea is a good one. Just as I was scraping the gasket off with a razor blade, I noticed high spots around each head bolt hole....
Using crows feet will reduce the torque, just like using an extension, so i always add a few ft. pounds to the mix to compensate.
--- End quote ---
Laping is a must but it has to be done correctly. As for the crows foot thing I'm not so sure, if the crows foot has an offset of one inch then it's going to add one inch to the length of your wrench if it stuck strait out the front. It would add one inch pound to every foot pound you torqued the bolt too do to the added length. Now if you 180 the crows foot it would subtract one inch pound per foot pound. Now maybe if it was 90 degrees to the wrench head the torque would be correct because you wouldn't be adding or subtracting any length to the wrench. Now you have to figure out how much torque you are losing to jaw spread if you are using an open end style crows foot. If you are using a boxed end style crows foot the torque loss would be a lot less do to the fact you have no jaw spread. Now if you are using an extension it's going to flex and subtract torque, so maybe if you had the crows foot sticking strait out the front and using an extension,the flex of the extension would make up for the added length of of the crows foot and you would wind up back at the proper torque value. I don't think you would though do to the fact that there are still more variables to consider. For example: Are You torqueing your base nuts on wet or dry???
--- End quote ---
HUH? Lol. No that all makes sense. I have always torqued head bolts/nuts wet. Thats a whole 'nother story.
Cause if you use engine oil, it will torque smoothly, but might give you a few extra foot pounds of unneeded torque. Combine that with a 180 open end crows foot... You are gonna have to subtract a couple inch pounds because of the 180, then add a few foot pounds because of the wet fastener. If you use WD40 with an open ended crows foot, and a six inch 3/8" drive extension, and a 3/8" to 1/2" adaptor.. .Well thats another issue.
J/K.. Geting tired...
kxpegger:
I used to be a calibration tech in the Navy.
Applying an extension to the load end (handle) will not change the moment on the arm so torque values will not change.
Applying an extension to the drive end will change (increase) the moment on the arm and will apply more torque than the setting indicates.
"A" distance = center point of drive end to the center point of load applied at the handle.
"B" distance = from center point of torque wrench drive end to the center point of the extension drive end.
"D" = desired torque at the end of the extension.
"S" = unknown torque setting using an extension.
Lets make "A" = 24 inches (torque wrench), "B" = 10 inches (extension) and we're looking for "D" = 300lbft and need to find "S" unknown (actual torque wrench setting with extension to achieve 300lbft).
S = D x A/A +B
S = 300 x 24 / 24 + 10
S = 300 x .70588
Answer: S = 211
Set your torque wrench to 211 lbft to achieve 300 lbft of torque with a 10 inch extension at the drive end of the torque wrench.
For your added enjoyment most click torque wrenches run +/- 4 % of indicated value. If set for 100 lbft your accuracy will be between 104 and 96 lbft, 50 lbft will be 52 to 48 and so on. If I remember right we were also taught that to get the +/- 4% indicated accuracy you had to be in the upper 75% of the torque wrenches range. An example would be a 0 - 100 lbft wrench. Your settings would have to be above 25 lbft for the torque wrench to be accurate.
jfabmotorsports.com:
This is what I use. It also work great on the sprocket nuts.
http://motionpro.com/motorcycle/partno/08-0134/
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