Head bolt torque #9 bolt
Thread Starter
Staging Lane
Joined: Apr 2011
Posts: 78
Likes: 0
From: Montgomery County, TX
Head bolt torque #9 bolt Posted this also on the perf truck forum.
Installing the heads on my 5.3 and was on step 3 and screwed up.
After completing step 2 , all 1-10 , 90*
So I read step 3 , four or five times to get it right in my head(mind)
1-8 additional 90* , 9and 10 50*
Well got to #9 thinking for some reason all 10 were additional 90* then 9 and 10 were additional 50.
Well on #9 I went 90* instead of 50* ! Argggh, I caught myself when I moved to #10, looked at the book again and realized I screwed up.
So will the extra 40* on #9 hurt anything? I left it as is and didn't lossen it or anything.
What ya'll think?
Thanks
Installing the heads on my 5.3 and was on step 3 and screwed up.
After completing step 2 , all 1-10 , 90*
So I read step 3 , four or five times to get it right in my head(mind)
1-8 additional 90* , 9and 10 50*
Well got to #9 thinking for some reason all 10 were additional 90* then 9 and 10 were additional 50.
Well on #9 I went 90* instead of 50* ! Argggh, I caught myself when I moved to #10, looked at the book again and realized I screwed up.
So will the extra 40* on #9 hurt anything? I left it as is and didn't lossen it or anything.
What ya'll think?
Thanks
well, believe it or not, it's probably looser than the rest. If I could get a bolt, I would replace it. It's probably ok, but that's taking a pretty good chance. If it fails, it's a lot of work and possible damage if you get coolant in the oil or vice versa
Thread Starter
Staging Lane
Joined: Apr 2011
Posts: 78
Likes: 0
From: Montgomery County, TX
Joined: Aug 2007
Posts: 24,241
Likes: 89
From: Turnin' Wrenches Infractions: 005
I'd either back it off 20 to 40 and run it or leave it and run it. Worse case it leaks a little and you have to start over anyway. Some purists might not agree that this is the best thing to do and I agree. But with a mild NA motor, I don't see the issue. If it was a forced induction or N20 motor then yeah I'd probably take it back off and do it the right way. As a tidbit, loosening a head can cause warping as you un-clamp it. Thats why i wouldn't start over unless it leaked. it was a minor mistake IMO.
Trending Topics
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
The only way to judge with any accuracy is to remember accurately how it felt twisting it in especially the extra 40deg . My hypothesis is as course is the threads are of those bolts , the threads in the block are most likely damaged some , how much ? hard to say . I know it takes a little bit of muscle to twist the bolt that amount of deg so unless thinking about it before and during it's easy to not really notice how it felt as it got easier to turn the bolt the last 10, 20, or 30 deg . You probably would be ok because of the other bolts clamping force , but at some point she will start leaking ,,,,probably at least 60 or 80 thous . Good luck
The only way to judge with any accuracy is to remember accurately how it felt twisting it in especially the extra 40deg . My hypothesis is as course is the threads are of those bolts , the threads in the block are most likely damaged some , how much ? hard to say . I know it takes a little bit of muscle to twist the bolt that amount of deg so unless thinking about it before and during it's easy to not really notice how it felt as it got easier to turn the bolt the last 10, 20, or 30 deg . You probably would be ok because of the other bolts clamping force , but at some point she will start leaking ,,,,probably at least 60 or 80 thous . Good luck
With TTY bolts the final pass stretches the bolts to just under yield. Turning a bit past gets a little closer to yield if not a bit into the gray area. Backing off doesnt un-stretch the bolt, it merely loosens it. His block threads are fine. He'll twist the bolt in two before pulling them out. Bet course is to leave it alone for now unless he just wants to pull the head and start all over with a new gasket and fresh bolts
Banned
Joined: Oct 2009
Posts: 992
Likes: 1
I hope you all realize that this TTY is a bunch of crap. You have no idea! where the bolt is on the torque curve, Its a good guess that usually works out ok AT BEST. ANYTHING left on the threads will effect it. How many of you actually know your threads are clean and dry with no left over film from coolant or oil? Don't worry about it because its just not that important. I personally woooood torque the bolts to 75ftlb and forget about it AND reuse the old bolts!
I wanna warn you about something else, YOU SHOULD take a punch and WHACK the head of every bolt on a aluminum engine before you try to remove the head bolts. If you don't you risk the bolts breaking off in the block. The action of hitting the head of the bolt seperates the bond between the bolt threads and the block.
Good luck
I wanna warn you about something else, YOU SHOULD take a punch and WHACK the head of every bolt on a aluminum engine before you try to remove the head bolts. If you don't you risk the bolts breaking off in the block. The action of hitting the head of the bolt seperates the bond between the bolt threads and the block.
Good luck
I hope you all realize that this TTY is a bunch of crap. You have no idea! where the bolt is on the torque curve, Its a good guess that usually works out ok AT BEST. ANYTHING left on the threads will effect it. How many of you actually know your threads are clean and dry with no left over film from coolant or oil? Don't worry about it because its just not that important. I personally woooood torque the bolts to 75ftlb and forget about
Originally Posted by 02Form
it AND reuse the old bolts!
Originally Posted by 02Form
I wanna warn you about something else, YOU SHOULD take a punch and WHACK the head of every bolt on a aluminum engine before you try to remove the head bolts. If you don't you risk the bolts breaking off in the block. The action of hitting the head of the bolt seperates the bond between the bolt threads and the block.
Banned
Joined: Oct 2009
Posts: 992
Likes: 1
I'm sorry to tell you this but if you lube thoses head bolts you will be in a world of hurt. Torque values and TTY values are with CLEAN DRY THREADS. Add anything into the equation and you will have trouble.
Also reusing head bolts is not reccomended by the company who sells them..................... trust me i've reused them MANY MANY times. I also stated I WOOOOOD reuse them....I didn't say anyone else should, Its your world do as you see fit.
Also reusing head bolts is not reccomended by the company who sells them..................... trust me i've reused them MANY MANY times. I also stated I WOOOOOD reuse them....I didn't say anyone else should, Its your world do as you see fit.
Banned
Joined: Oct 2009
Posts: 992
Likes: 1
I strongly disagree. Any engine builder worth a crap knows to clean the bolt, and block, and lube the threads if called for. When you torque a bolt, you are stretching the bolt. That's the whole idea. That is why a stretch gauge is better than a torque wrench on a rod bolt. That's why TTY is used instead of a torque figure...that is what the bolt is designed for.
I don't know what GM does on the assembly line...but use their recommended procedure. Just as you do with ARP bolts. ARP recommends a lube. The lube you use determines the torque figure. If GM says do it dry, then that is the procedure you use and torque them accordingly. By the way, I do believe the GM bolts have thread locker on them if I'm not mistaken.
My whole point is that manufacturers don't make up these procedures because they feel like it. There is a valid reason. And since they have to buy the new bolts when it's under warranty, I would say it is very important to use new bolts torqued appropriately. Again, please do as you feel best for your situation. But I would follow the recommendation of the manufacturer...GM, ARP, etc.
My whole point is that manufacturers don't make up these procedures because they feel like it. There is a valid reason. And since they have to buy the new bolts when it's under warranty, I would say it is very important to use new bolts torqued appropriately. Again, please do as you feel best for your situation. But I would follow the recommendation of the manufacturer...GM, ARP, etc.
I made the same mistake on my car... It was the last bolt of the last head haha! I called a bunch of different 'big name' head guys and they all said that as long as it didn't strip out, just leave it be.
Sigh.
To the OP. You made the right choice in leaving it alone. Backing it off would have turned a minor mistake to a major mistake. It is just stretched the same as 1-8, you have not compromised the fastener in any way.
To some of the other guys that apparently think torque-to-yield and torque-to-angle are a conspiracy... you need to learn a few more things. When you torque a fastener, you are trying to achieve a load using bolt stretch. You have a major problem to deal with, friction... This is why lubricants are used. Each has its own friction factor. That's why ARP gives its moly-lube torque and one for motor oil. There is no direct link between torque and bolt stretch because of the variety of materials and lubricants. Only estimates.
When you tension a fastener using TTY or TTA you take advantage of the Threads-per-inch characteristic of that fastener. Yes, the first step will include a torque, but it's typically low (with lower friction forces) and just to develop a common starting point.
SO.... If you have have a bolt with 8 TPI, and you tighten it one turn, you have just stretched that bolt .125" (1"/8=.125"). That is EXACTLY how much bolt stretch you just introduced. TTA fasteners stretch only within the elastic regime and are re-usable. TTY fasteners stretch through elastic and into plastic deformation. Meaning TTY fasteners do not spring back to original shape. Using TTY, manufacturers can get the same torque with smaller bolts or more torque with the same bolts.
To the OP. You made the right choice in leaving it alone. Backing it off would have turned a minor mistake to a major mistake. It is just stretched the same as 1-8, you have not compromised the fastener in any way.
To some of the other guys that apparently think torque-to-yield and torque-to-angle are a conspiracy... you need to learn a few more things. When you torque a fastener, you are trying to achieve a load using bolt stretch. You have a major problem to deal with, friction... This is why lubricants are used. Each has its own friction factor. That's why ARP gives its moly-lube torque and one for motor oil. There is no direct link between torque and bolt stretch because of the variety of materials and lubricants. Only estimates.
When you tension a fastener using TTY or TTA you take advantage of the Threads-per-inch characteristic of that fastener. Yes, the first step will include a torque, but it's typically low (with lower friction forces) and just to develop a common starting point.
SO.... If you have have a bolt with 8 TPI, and you tighten it one turn, you have just stretched that bolt .125" (1"/8=.125"). That is EXACTLY how much bolt stretch you just introduced. TTA fasteners stretch only within the elastic regime and are re-usable. TTY fasteners stretch through elastic and into plastic deformation. Meaning TTY fasteners do not spring back to original shape. Using TTY, manufacturers can get the same torque with smaller bolts or more torque with the same bolts.