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CYLINDER HEAD - Retorque


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Hello.

 

Having recently completed a CH replacement on my Mk2 Vitesse, I will be re-torqueing when it has 300 miles under its belt.

 

The torque range for this car is between 65 & 70.

 

I tightened the nuts to 66 to give a bit of flexibility on re-torque.

 

As such is it worth slackening & tightening each nut in turn up to 70 OR as they are currently on 66 can I just increase the torque to 70 and then job done ??

 

Will be grateful for a steer on this.

 

Thank you.

 

Richard.

 

PS: joined TSSC at Stonleigh, last weekend, - a job I have been meaning to do for years !!

 

 

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66lbs/ft?    How long ago did you calibrate your torque wrench?

Unless it was very recently, and you have a micrometer wrench so that you can set it so accurately, the actual tension will be no closer than 10% of that notional figure.  At best!

Micrometer wrenches cost!

 

I calibrated my standard wrench recently, after bit of a problem and found it was under-reading by 30%!

 

Calibration:  You can buy a digital torque gauge, that fits between the wrench and the work, or set the gauge in a vice: http://www.ebay.co.uk/itm/3pc-Digital-Torque-Wrench-Adaptor-Set-Electronic-Digital-Display-1-4-3-8-1-2-/171668867943?pt=LH_DefaultDomain_3&hash=item27f8430b67

 

OR, send your wrench away to be calibrated: http://www.calibrate.co.uk/torque/?gclid=CjwKEAiAveWnBRCzjqf4zpuUkGYSJABcoZbHGpThCFmXQpboT_E4HA7vgj5VLWPTEOJfiBDmO5iZ1RoC1brw_wcB

You will note from that site that even after calibration the toll cannot be better than 6% accurate.   So your head could be anywhere between 62 and 73lbs/ft

 

OR, do your own check.    Clamp the wrenches drive shaft in a vice, so that the handle moves in a vertical plane.    Measure a point on the handle, so that you can hang a known weight on it at a known distance.

Say the handle gives you a point 18" (1.5ft) from the drive, and you can hang a known weight there, say 12 kgs (26lbs) (a 2L saloon flywheel).    That's just under 40lbs.ft.    Set the wrench to 40, hang oyur weight - does it click?  Spot on!

 

JOhn

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Hi.

 

Darren - thanks for that, very useful.

 

JohnD - micrometer wrench and thanks for flagging those points up.

 

Much appreciated.

 

Regards.

 

Richard.

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