Torque values

Please use this forum to detail how to do various tricky jobs on your Midas.
Your endeavours may help others following your path in the future. Tip.... Photos/Pictures speak a thousand words. Midas related FAQs are also in here.

Moderator: The Midas Forum Staff

Torque values

Postby jonevansmidas » Mon Jul 13, 2009 10:17 pm

On looking through the various workshop manuals, there appears there may be some variation between the torque required to instal say, a cylinder head stud in the block and the torque to tighten the nut on the cylinder head. Looking at the thread sizes, it appears that the stud torque may be about 75% of the nut torque.
I realize that Adrian Dodd has the touch, but I have three torque wrenches which are calibrated and I need to use.
Should the two torques be the same, bearing in mind that the stud may have Studlock applied and the nut Nutlock applied?
jonevansmidas
 
Posts: 8
Joined: Tue Dec 09, 2008 12:33 am

Re: Torque values

Postby manifold » Mon Jul 13, 2009 11:26 pm

I've never bothered checking the stud torque myself.

Always checked the studs screw home into their respective holes to the end of their depth, then applied torque to the nuts as per the manual. ie 50lbs on cylinderhead nuts.

its always worked for me.

cheers,

david

I never use thread lock on cylinder head, but neither do I oil them either. just dry and cleaned threads.
Midas Cars Forum & Facebook Page Founder

Midas Gold Convertible: 1380 steel 16v KAD & 5 sp dog box, Titanium mania, KAD fr/rear callipers, CF Steering

Midas Gold Coupe: 1380 7 port xflow, SC/CR gearbox, Titanium mania, CF Steering & seats.
User avatar
manifold
 
Posts: 1724
Joined: Tue Dec 02, 2008 7:34 pm
Location: Lancaster, Lancashire

Re: Torque values

Postby ACDodd » Thu Jul 16, 2009 11:03 am

Studs hand tight only.

AC
ACDodd
 
Posts: 32
Joined: Wed Dec 31, 2008 11:15 am

Re: Torque values

Postby jonevansmidas » Thu Jul 16, 2009 9:54 pm

Many thanks Adrian - that would explain a lot!

Cheers
Jon
jonevansmidas
 
Posts: 8
Joined: Tue Dec 09, 2008 12:33 am

Re: Torque values

Postby gooseman » Wed Nov 04, 2009 6:33 pm

Some years ago i worked at a materials testing laboratory & we did quite a lot of fastener testing, a lot of yield/tensile tests on full size bolts up to 1.5" diameter and reduced sections for sizes above that, this was done on massive hydraulic machines. We also did torque wrench calibration but these were huge wrenches for bridge construction however i did test a cheap wrench i had bought for less than $20 & it was very accurate to 150 ft/lb.
There was always controversy about the relationship of torque to actual tension in the fastener itself & we had a device called a Skidmore-Wilhelm tester. This was a hydraulic device with a pressure gauge attached & the fastener was fitted into the center of it & tightened to the appropriate torque value, the gauge would tell the tension that was exerted.
I planned to fit some ARP studs to my Fiero V6 in preparation for turbocharging it so i brought the Skidmore/Wilhelm home so i could check the values & subsequently did more than a hundred tests on the studs. I tried several different lubricants on the threads even a slippery assembly lube to look at the values i would get.
What im getting around to saying is that you need to use at a minimum some 10w30 oil on any & all threads when you torque (or otherwise) to achieve a proper value NOT just screw them up dry...jim
gooseman
 
Posts: 51
Joined: Wed Jun 17, 2009 6:37 pm


Return to How to Guides & Frequently Asked Questions (FAQs)

Who is online

Users browsing this forum: No registered users and 8 guests

cron