Cylinder head install

[fenderman]

Just had a quick question regarding installation of the cylinder heads.

Prior to installing my remanufactured heads with new TTY bolts I had my torque wrench calibrated. I chased the threads in the block with a thread chaser until I could turn it all the way in each hole with just my fingers. During the installation procedure however on some of the bolts the torque wrench gave me a really quiet click instead of the loud positive click I am used to hearing but I stopped in order to keep from overtorquing the bolt. When I went through the final tightening procedure by turning them 120 degrees, the bolts towards the rear of the engine seemed slightly easier to rotate than the ones up front. Is this normal? I know I've permanently crushed the gaskets and stretched the bolts and that if I were to do this again I would need new gaskets and new bolts but before I rip it apart I just wanted to see if anyone else experienced this. The last thing I want to do is get it all together and then find out a few thousand miles later that I'm going to have to do it all over again.

[Blizzard242]

Re: Cylinder head install

I would suggest making sure of your torque wrench. If you had only a few quiet clicks you should have torqued them again. They're not going to go past the torque you have it set at if you pull the torque wrench nice and easy and not jerky.

[ssms5411]

Re: Cylinder head install

I would suggest making sure of your torque wrench. If you had only a few quiet clicks you should have torqued them again. They're not going to go past the torque you have it set at if you pull the torque wrench nice and easy and not jerky.

X2 , Def. need a torque wrench and go by them again after you have tq them down in the same sequence.

[Pewter02Camaro]

Re: Cylinder head install

Also did you torque step them to insure even pressure?

[fenderman]

Re: Cylinder head install

Well, to reiterate I do have a torque wrench- in fact, I recently had it calibrated as well. Which torque wrench out there lets go of the bolt when it reaches the desired torque? The one I have will still allow you to put excess pressure on the bolt after it clicks. The click is not a disengagement but rather an indicator to stop pulling. I have also never operated a torque wrench by "jerking" on it. I always apply steady even pressure in a 90 degree angle to the wrench and hold it by the knurled handle. I do know how to operate a torque wrench and have had mine for many years. I don't drop it or use it to break bolts loose. I don't use it to hammer things into the ground. I was simply asking if it was normal for a torque wrench's "click" to vary in volume. I also do not see the benefit once the wrench clicks of applying additional force. I don't want to have to pull the heads off to rescue a broken bolt.

I read all the time about "torque stepping" and wonder why in the world none of the manuals I read include this additional information. The procedure as it is written in the manual says to tighten the bolts in 2 stages. I'm sure some people will say 3 stages and others will recommend 4. To go way overboard I could go in 37 1 ft. lb increments but would there be any real benefit to doing so? If you cannot properly torque a cylinder head in 2 stages why does the manual say otherwise? Of course I seated all the bolts with a regular socket wrench first in the proper pattern so technically I could say I included a 3rd step but I didn't set it to a specific torque.

Thanks for the replies. I guess I'll go and have the calibration rechecked and be done with it.

[Andy H]

Re: Cylinder head install

My torque wrench does that sometimes too. When it just barely clicks for me, I let off and then I turn again to get it to click again but I don't go past the click. Usually the second or third time I do it, the click is like it should be. Sometimes it does involve a little more torque the second time to get it to click right.

I figured mine done this because it was a cheap great neck torque wrench from autozone. But I do know what you are talking about though.

[cam98aro]

Re: Cylinder head install

i have never used a torque wrench that acted like yours

i would get it checked out, again, whoever calibrated it may have accidentally messed something up... as long as you go back over the bolts and it makes the normal click, i would say you are good to go, if mine did that, i would re check it a few times, then go on my way.

the reason why they tell you to torque the bolts down, then go an extra 120* is just to make sure you are torque stepping, so someone just doesnt put it on the max torque and have the head not fully seated.

personally, i think that torque stepping is more important on things like an intake manifold, especially because they are usually made with softer metals or plastics that can warp way easier than a head, 2 steps is fine for a head, especially with the better head gaskets they use today

[bigbrian442]

Re: Cylinder head install

I was simply asking if it was normal for a torque wrench's "click" to vary in volume.

Yes. I have a Snap on torque wrench that acts the same when set at the low end of it's range.

[Blizzard242]

Re: Cylinder head install

When I said, "They're not going to go past the torque you have it set at if you pull the torque wrench nice and easy and not jeky." I meant if you pull it again, it should click right away. I use torque wrench's that vary from 30lbs to 650lbs. I know if you're not sure of the torque you can pull it again easily enough so that it does not tighten the bolt more but will click if you have the bolt torqued to the specs you have it set at. A torque wrench will do that sometimes. I'm not saying yours is messed up or that you need to have a calibrated again. I meant, make sure of the torque by clicking it off again.

[fenderman]

Re: Cylinder head install

Thanks for the input, and if I sounded like an *** with my last comment I apologize as it was not directed at anybody here. This is just incredibly frustrating since I've been trying to pay such close attention to detail during this process.

Once again, thanks for the input. It is much appreciated.

[fenderman]

Re: Cylinder head install

One other quick question I had. When reading up on TTY bolts I read that the final rotation angle is necessary to ensure even loading on the bolts since bolt lengths, dirty threads, etc. can affect torque readings and result in uneven loading. Since the initial pass is torque based, if the torque values do not ensure even loading how does rotating all the bolts the same amount of degrees suddenly even the pressure out across the head? Sorry if that sounds stupid but I have to be misunderstanding or misreading that.

[bigbrian442]

Re: Cylinder head install

One other quick question I had. When reading up on TTY bolts I read that the final rotation angle is necessary to ensure even loading on the bolts since bolt lengths, dirty threads, etc. can affect torque readings and result in uneven loading. Since the initial pass is torque based, if the torque values do not ensure even loading how does rotating all the bolts the same amount of degrees suddenly even the pressure out across the head? Sorry if that sounds stupid but I have to be misunderstanding or misreading that.

They are betting that the lower torque value used before the angle is more accurate than a higher torque value.

[caspernicus]

Re: Cylinder head install

TTY bolts are designed to 'stretch' once a certain torque
spec is reached.