torque or angle torque

[wellcraftpower]

5.7 vortec heads , my torque spec sheet gives 2 different ways to torque with angle torquing being prefered. I don't have that wrench, is it necessary.

 

[Scott Danforth]

TTY bolts are one time use and you torque them, then crank them to a specific angle.

 

[ESGWheel]

Tool is fairly simple and inexpensive. About $10 fm AZ, link.

 

[kenny nunez]

All the big box auto stores have them.

 

[kd4pbs]

I have often used a digital angle gauge from Hazard Frought that I had purchased years ago...

https://www.harborfreight.com/digital-angle-gauge-63615.html

Can be used for so much more than just the ones made for that job.GM never published a torque spec for the Vortec, from what I have determined - just the initial torque spec plus the degrees from that.

 

[Scott06]

5.7 vortec heads , my torque spec sheet gives 2 different ways to torque with angle torquing being prefered. I don't have that wrench, is it necessary.

On the wifes mini I bought HF angle torque wrench broke on the second bolt... so I just marked the bolt heads with a sharpe for the angles. I dont think the angle is that precise

 

[guy48065]

On the wifes mini I bought HF angle torque wrench broke on the second bolt... so I just marked the bolt heads with a sharpe for the angles. I dont think the angle is that precise

HF now has several torque-angle digital wrenches. Which one broke?
(I'm pretty sure they're all rebranded tools from other mfrs)

 

[Scott06]

HF now has several torque-angle digital wrenches. Which one broke?
(I'm pretty sure they're all rebranded tools from other mfrs)

This POS, yeah it’s sold under abiut 15 different brands https://www.harborfreight.com/38-in-drive-5-to-100-ft-lb-digital-angle-torque-wrench-64915.html

 

[guy48065]

This POS, yeah it’s sold under abiut 15 different brands https://www.harborfreight.com/38-in-drive-5-to-100-ft-lb-digital-angle-torque-wrench-64915.html

Yep. Not high on my list of desirable torque wrenches. Same tool as Eastwood, Westward, AC Delco, + many others. All made in Taiwan by Eclatorq with very slight cosmetic differences.
Still shouldn't have broken if used within it's capacity. The ones I've used & calibrated have always gone to 100% without fail.
Digitals have an annoying habit of going to sleep while you delay getting going...then SNAP!

 

[Scott06]

Yep. Not high on my list of desirable torque wrenches. Same tool as Eastwood, Westward, AC Delco, + many others. All made in Taiwan by Eclatorq with very slight cosmetic differences.
Still shouldn't have broken if used within it's capacity. The ones I've used & calibrated have always gone to 100% without fail.
Digitals have an annoying habit of going to sleep while you delay getting going...then SNAP!

the rachet head broke set at 85 ft lbs. I bought a used snap on, No sense screwing around with angles on a cheap wrench. Because this was middle of doing a timing chain on the wife's mini I punted and just marked the bolt head for the angles, which also worked just fine as long as you can get at the bolt head.

 

[cyclops222]

That angle is really going blind. The thread that should be fine. Could be defective. Pull like crazy. Still not a easy know if the stress is correct. What is stretching ?

 

[Scott06]

What is stretching ?

the bolt is what stretches. I think bolts designed this way hold their torque better.

Mini uses it on the cam and crank sprockets there are no keys ways or traditional timing marks. You buy a tool to index the cams, put a pin in the flywheel, tension the timing chain and lock them down with these single use bolts...

 

[ESGWheel]

Torque is all about stretching the bolt to apply the needed clamping force. There is both running torque and final torque. Running is the amount of torque required to overcome the inherent friction between the bolt and its ‘nut’. Final torque is the calculated torque by the engineers to stretch the bolt just so to apply the needed clamping force. And technically, the running torque is ADDED to the final torque to get the torque that should be applied to achieve the needed stretching. In fact, measuring the bolt stretch is a more accurate and consistent way of achieving the needed clamping force and is typically used in critical applications. Instead of a torque wrench, use a “stretcher” (on a stud) to stretch it and then run the nut down to engage the mating surface. It’s pretty cool.

I have asked in the way past if the torque specs we are all familiar with needs to have the running torque added to it and have never gotten a clear answer. I suspect the engineers know that no one will do it, so they add into their estimate of the running torque to the final and then publish that number.

Understanding all of this highlights the critical importance of clean threads when doing assembly. For example, changing out the ex-manifolds and risers > run a thread chaser (not tap) thru ALL the holes to clean them up before assembly. Requires getting the debris out of the hole as well, using air or brake clean, etc. Run the chasers even in new items to ensure no paint or other crap gets in the way.

For these heads which are torqued and then degreed, I suppose the engineers, knowing they will get such and such clamping force with so many degrees of rotation, hedged and understood applying a lesser torque and then doing the degrees would create a more consistent clamping force.

Sorry did not mean to go on so…

 

[guy48065]

Marking the head is fine. Several techs where I worked preferred to do it this way--even tho we had torque-angle digitals in every size.
The wrenches are amazing IMO. Great for doing TTY in tight spaces because they keep track of the angle increments if you need to ratchet to get there in steps.

 

[cyclops222]

Lets invent a process to sell unlimited amounts of bolts.
Done

 

[guy48065]

I think we found a guy who reuses TTY bolts.