TTY head bolts with engine in-vehicle

[strutaeng]

I've have also used oem bolts and tighten the bolts as if they were arp bolts and have one to fail yet.

What?!

I was thinking of "Hooks Law stress-strain equation" as I was yielding the bolts on the last 2 passes: the force kinda seems to vary to keep the rotation going to keep the angle going at a constant rate.... Kinda hard to explain... certainly takes some grunt to do that, LoL. I'm glad I had lunch prior to doing that.

 

[ivin74]

What?!

I was thinking of "Hooks Law stress-strain equation" as I was yielding the bolts on the last 2 passes: the force kinda seems to vary to keep the rotation going to keep the angle going at a constant rate.... Kinda hard to explain... certainly takes some grunt to do that, LoL. I'm glad I had lunch prior to doing that.

That's why it used the arp tighten method.

 

[strutaeng]

That's why it used the arp tighten method.

I guess what I'm shocked about is that TTY (torque-to-yield) and ARP (torque-to-ft-lb) are completely different metallurgy and NOT interchangeable with one another...

I'm not gonna argue that you had good results in your case; rather, I'm going to follow manufacturers' recommendations...

 

[Donal]

I guess what I'm shocked about is that TTY (torque-to-yield) and ARP (torque-to-ft-lb) are completely different metallurgy and NOT interchangeable with one another...

I'm not gonna argue that you had good results in your case; rather, I'm going to follow manufacturers' recommendations...

Sounds like its time to do a stretch to failure comparasion test for the used oem versus the ARP bolt. I will search for maybe two of each.
Note that these are cap screws not bolts. But a common misuse of the terms. Bolts have nuts. Cap screwss screw into a theaded hole in a machine or machine component.

 

[wjburken]

I guess what I'm shocked about is that TTY (torque-to-yield) and ARP (torque-to-ft-lb) are completely different metallurgy and NOT interchangeable with one another...

I'm not gonna argue that you had good results in your case; rather, I'm going to follow manufacturers' recommendations...

This has been discussed a few times.

Torque vs Tension

Here is an interesting video demonstrating Torque vs Tension on a bolt and how bolt and thread condition can affect them.

www.tahoeyukonforum.com

Two different approaches.

Bolted joint design is an interesting study.

Both ARP and TTY/TTA bolts are fine, if one understands what is going on. They just use different methods to achieve the necessary clamping force.

TTY/TTA bolt specs are calculated to take into account how many degrees of turn of the bolt, after an initial torque is achieved, are required to induce the proper amount of strain/stretch in the bolt to achieve the necessary clamping force. This takes the amount of friction in the threads and under the bolt head out of play as they can vary widely.

For ARP, they take the path of having a consistent level of friction and therefore can prescribe the proper torque needed to achieve the needed clamping force. That is why they have ARP Ultra-Torque lubricant and some pretty specific installation instructions.

Note that these are cap screws not bolts. But a common misuse of the terms. Bolts have nuts. Cap screwss screw into a theaded hole in a machine or machine component.

I get where you’re coming from with you’re explanation of the difference between a bolt and a screw having been designing “bolted” and “screwed” connections for quite sometime,

What's the Difference between Bolts and Screws? | OneMonroe

The difference between a bolt and a screw is bolts are used to assemble to unthreaded objects, typically with the use of a nut. In comparison, screws are used to assemble objects with threads. Here's the thing, though: not all objects in which screws are used already have threads.

monroeengineering.com

but when ARP actually refers to them as bolts, I’ll use the term bolt when referring to them.

The Official ARP Web Site | Technical Information

arp-bolts.com

 

[Trey Hardy]

I've have also used oem bolts and tighten the bolts as if they were arp bolts and have not had one to fail yet.

Last engine I did the heads had been off 3-4 times and it ended up pulling the threads out the block. I was using stock bolts at the time.
Ended up buying a time sert kit to repair the block

 

[Fless]

What?!

I was thinking of "Hooks Law stress-strain equation" as I was yielding the bolts on the last 2 passes: the force kinda seems to vary to keep the rotation going to keep the angle going at a constant rate.... Kinda hard to explain... certainly takes some grunt to do that, LoL. I'm glad I had lunch prior to doing that.

 

[strutaeng]

I got the rockers installed on both sides. I had bought a pushrod checker (adjustable length type), but couldn't really figure out how to use it. And I don't have calipers that measures that length.

I watched a video from Richard Holdener on how to check. I got 1 1/4 turns from zero lash to where the rockers were seated. So the original 7.400" pushrods seem the correct length still. Torqued to spec...

 

[strutaeng]

I pressure washed the engine bay. Got the flex plate installed and the harmonic balancer. Dang, 240 lb-ft on the old balancer bolt, then remove and install the new one: 50 lb-ft, plus 140 degrees!

 

[strutaeng]

Took last week off because one of my girls had her first communion. So we had family over.

I got the engine back into the truck today. I hope this week to complete everything back on it.