Need center to center measurement for Tool 2079

[syljay]

> From: "Kunz, Bob" <bob.kunz at hp.com>
> The 'torque' thread rises again...
> 
> The math is actually simple and will answer all your questions about length of extensions. It goes this way:
> 
> T = Torque needed at the bolt
> A = Applied torque of the wrench
> L = length of the torque wrench
> E = length of the extension
> 
> A = (T * L) / (L + E)
> 
> --bob

***** Yeah, aint this great!!!?  hehehe

Did you know, that the tool 2079 torque value of 232 ft lbs only works 
if you use a torque wrench that is exactly 41" long? Thats something 
the Bentley forgot to tell you about.

Here are the values of torque settings to get 332 ft-lbs at the bolt 
when using tool 2079 with various length torque wrenches:

Length of wrench     torque setting
24"                  232 ft-lbs
30"                  238 ft-lbs
36"                  250 ft-lbs
41"                  258 ft-lbs <---------
48"                  266 ft-lbs

Seems counter-intuitive, eh? One would think that the more 
macho(longer) the torque wrench, the lower the torque wrench setting 
to be used.

To puzzle it out:
1. What force is exerted by the operator using a 41" wrench?
force applied = torque/distance
force applied = 258/3.416  = 75.5 lbs   (41"/12" = 3.416 ft)

2. What is the total lever arm that the crank bolt sees?
Wrench length + tool 2079  = 41" + 11.75" = 52.75" = 4.4 ft

3. What is the torque on the bolt head?
Torque = distance X force applied
        = 4.4 ft X 75.5 lbs
        = 332.2 ft lbs


Are you still in disbelief?
Think of it this way. If you had a 100 ft torque wrench, would the 
11.75" tool 2079 length be significant? Nope! You can forget tool 
2079. The longer the torque wrench becomes, the less significant is 
the extension length.
What setting would you set the 100 ft torque wrench to get 332 ft-lbs 
at the crank bolt?
332 ft-lbs would be the setting.


SJ in NJ