Stupid Question #1437 - Boo Boo w/Head Bolts

[it's paid for]

Hello,

I think I screwed up again . . . when I torqued the head bolts, I think I used my 3/8 head, 5" long extension . . . I have a 1/2" head extension also . . . but I can't remember which one I used . . . I have two 12 point 10mm Craftsman sockets - one takes 3/8 & the other is 1/2 . . .

. . . so . . . my question . . . should I go back, remove the valve cover & oil pump gear cover and use the 1/2" extension with the torque wrench to retorque the bolts in order to get a more accurate torque setting on the head bolts?

. . . I didn't know I wasn't supposed to use an extension while doing this . . . what an idiot . . . I'm learning a lot from this . . .

Thanks,

IPF

[AccordEpicenter]

yea id just pop off the vc and retorque, and you should use the right sequence, no extensions this time

[it's paid for]

. . . I think I'll have to use an extension . . . I'll see if I can do it without an extension, but my engine is still in the car & my torque wrench is quite long, using a 1/2" drive . . . if I can't tighten all of them without the extension I'll make sure I'll use the 1/2" extension - that should minimize the inaccuracy of the torque vs. using the 3/8" extension - right? Also, I'll be very careful to use the right sequence - thanks,

IPF

[POS carb]

why would the extension affect torque unless the extension has a bend in it?

[dXsquared]

there is a formula that i learned for the length of extension and how much extra tq you set the wrench at... i would just put another 5-10 lb/ft on the wrench and re torque them all in the proper sequence

Travis

[AccordEpicenter]

yeah its more important that you get all the bolts the same torque than it is to get them the right torque, so id set it like dx hatch is tellin you and just go to 55 lb ft and tighten them all down with the short extension. With any extension you will lose torque through it. Its best illustrated trying to take off a large bolt with an impact wrench but it wont come off because the long long long ass extension you have keeps absorbing the torque, and your bolt wont come off, until you use no extension that is.

[AZmike]

I agree with POS. An extension acts as a torsional spring (and adds extra inertia) and is able to absorb the energy of an impact wrench. When tightening head bolts the motion is slow enough that I don't see how an extension could affect the reading. If 49 ft-lb of torque goes out of the wrench (that isn't moving) what else applies the reaction torque besides the bolt? Torque can't just disappear in a system where nothing is accelerating.