Author Topic: Torque wrench  (Read 9136 times)

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Offline martinfan30

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Torque wrench
« on: March 11, 2009, 12:13:09 AM »
What are you guys using to torque the head bolts(jug to case)? Looks like a tight fit for any sockets I have...
2000 KX500
2005 XR650L

Neither are stock, and both are great desert bikes.

Offline KXcam22

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Re: Torque wrench
« Reply #1 on: March 11, 2009, 03:15:30 AM »
This won't be any help but I use a regular box end wrench and torque them by feel. There are crowsfoot wrenches available that fit onto atorque wrench. Cam.

Offline martinfan30

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Re: Torque wrench
« Reply #2 on: March 11, 2009, 03:44:57 AM »
This won't be any help but I use a regular box end wrench and torque them by feel. There are crowsfoot wrenches available that fit onto atorque wrench. Cam.

I didn't even think of crows foot wrenches...

I've been a mechanic my whole life and have a pretty good feel for torque without a wrench myself. Just want this thing to come out perfect. Not anything against your method, as I've used that in the past myself with no problems.

Whats the general consensus on this? Does everybody use a torque wrench on the head, or just by feel?
2000 KX500
2005 XR650L

Neither are stock, and both are great desert bikes.

Offline cbxracer30

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Re: Torque wrench
« Reply #3 on: March 11, 2009, 02:37:27 PM »
I also used the " By Feel " method but we've been racing for about 10 years and I think I can replace a topend in my sleep in fact I'm pretty sure I've dreamt about it way more than once . It's also a good idea to lap the head in every so often , harley make a nice head lapping tool you just put a little valve lapping compound on it and rub away, but in a pinch a sheet of sand paper on a piece of glass wetted down will work just fine, takes the little tweaks out of the head.
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Offline BDI

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Re: Torque wrench
« Reply #4 on: March 11, 2009, 02:42:04 PM »
I use crows feet but it has an impact on the torque value. At least it's close and their all the same.
Smoke every cigarette like It's your last and ride like you stole something!!!

Offline martinfan30

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Re: Torque wrench
« Reply #5 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.
2000 KX500
2005 XR650L

Neither are stock, and both are great desert bikes.

Offline BDI

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Re: Torque wrench
« Reply #6 on: March 11, 2009, 04:26:02 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.
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???
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Offline martinfan30

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Re: Torque wrench
« Reply #7 on: March 11, 2009, 04:41:28 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.
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???



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...


2000 KX500
2005 XR650L

Neither are stock, and both are great desert bikes.

Offline kxpegger

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Re: Torque wrench
« Reply #8 on: March 12, 2009, 01:49:00 AM »
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.



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Offline jfabmotorsports.com

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Re: Torque wrench
« Reply #9 on: March 12, 2009, 02:29:31 AM »
This is what I use. It also work great on the sprocket nuts.

http://motionpro.com/motorcycle/partno/08-0134/
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Offline KXcam22

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Re: Torque wrench
« Reply #10 on: March 12, 2009, 02:37:13 AM »
Wow,
  Sounds like I may be closer "by hand". I thought torquing them wet was when I have a beer in the other hand. But seriously, adding a lubricant causes a +10% increase in the torque acheived.  I threadlock my base studs with blue (which is also a semi-lube - I am told +5%). Cam.

Offline TheGDog

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Re: Torque wrench
« Reply #11 on: March 12, 2009, 06:48:03 AM »
Please forgive the n00b question... but what it is a "crows foot" as you all are reffering to here in this context?

And some definition to what the term "lapping" refers too?

From the context clues of the sentence it was used in... it sounds like some method/procedure for making sure the head-to-cylinder surface junctures are as planar/flat as possible so that the gasket seals proper... am I understanding it right?
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Offline martinfan30

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Re: Torque wrench
« Reply #12 on: March 12, 2009, 07:26:11 AM »
Wow,
  Sounds like I may be closer "by hand". I thought torquing them wet was when I have a beer in the other hand. But seriously, adding a lubricant causes a +10% increase in the torque acheived.  I threadlock my base studs with blue (which is also a semi-lube - I am told +5%). Cam.

This brings up another question... Do you retorque the nuts after a certain amount of time with cometic gaskets?
2000 KX500
2005 XR650L

Neither are stock, and both are great desert bikes.

Offline Friar-Tuck

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Re: Torque wrench
« Reply #13 on: March 12, 2009, 09:20:10 AM »
 G,
Here's a link to "crows foot"
  http://buy1.snapon.com/catalog/tools.asp?tool=all&Group_ID=272&store=snapon-store
  Don't be put off by the "Snap-On" price..   Craftsman,SK,Proto, Mac etc will be much cheaper. 

The link in the above post by Martin  for the motion pro tool will fit the bill also.
  http://motionpro.com/motorcycle/partno/08-0134/

Thanks for taking the time to post  info on the Torque stuff Pegger.
Tuck\o/

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Offline Johnniespeed

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Re: Torque wrench
« Reply #14 on: March 12, 2009, 11:25:25 AM »
Call me a crude dude if you must, but I also am torquing by feel method. I think I may have put more fuel through my bike than most guys ever will, and absolutely no problems have ever occurred. I prefer a little lube on the threads to obtain a more even feel. I have been reringing about every 250 gallons and all is well, the base always stays sealed and tight, I also only use OEM gaskets.
 John
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