Over torqued stock head bolts, valve lash changes!

Big Blue24 said:
I have read numerous accounts of guys buying arp studs and replacing them one at a time for "extra insurance." Then two months later they loose a gasket.

I have always questioned the practice of loosening and retightening fasteners that clamp down a head gasket.
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I feel the same way, forget the re-lube process dduring a re-torque on studs, asking for trouble.
 
purplepuller said:
Your change in valve lash was in the temp change of the motor.On motors with cast block and aluminum heads the lash increases with heat.And on motors with cast on cast it will decrease. I have seen up to .010 change in lash from hot to cold changes. mainly .004 to .006 in the average change. After you tourqe the cylinder head once that gasket is fully compressed.
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all metal expands with heat , iron expands less then aluminum, . .004 is about right for a cast iron block, and if it had been aluminum, it would have been more.


A lot of gasket problems is in tune,
 
Big Blue24 said:
I have rebuilt many motorcycle and snowmobile engines in my life. When I was really young and had zero funds, I played around quite a bit trying to reuse head gaskets. Once you let tension off the head bolts, the gasket is ruined. I have tried this many times and even if you exceed torque specs, used gaskets in their original location do not seal.
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I don't know how many times I reused headgaskets on jetski's with zero issues. Done them several times on snowmobiles. Most of these are just metal gaskets though.
 
I just rebuilt a 4bt . The machine shop gave me engine specs that included torque specs. Head, rod ,and main all had so many pounds of torque then either 90 degree or 60 degrees turn after meeting torque spec. Any one have any issues with this practice?
 
I do what Gene does; Just tighten them up a little every couple years. So far my original 188,000 mile head gasket and head bolts are still holding. The torque has crept up to about 135 ft lbs now so I think I'm at their limit.
 
zippywildfire said:
I just rebuilt a 4bt . The machine shop gave me engine specs that included torque specs. Head, rod ,and main all had so many pounds of torque then either 90 degree or 60 degrees turn after meeting torque spec. Any one have any issues with this practice?
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it depends on the fastener. If they're torque to yield, that is the correct procedure
 
Forrest Nearing said:
it depends on the fastener. If they're torque to yield, that is the correct procedure
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Doesn't matter if they are TTY or not, its still an acceptable practice if used with the proper amount of turn afterwards. All you are looking for is a given stretch on a fastener. We use the torque-turn method lots at work. Just need specs to follow by.
 
Stock torque to yield bolts are designed to have a fairly forgiving range of install specs that yields consistent clamping load . That are installed with a mass production machine that torques all the studs at the same time . Cheap , reliable in their range .
ARP did the research , and it was a very extensive process. The results were on another thread , all over the map. You might get a few bolts to acheave more torquer , a few more yielded as designed , and produced no more then stock, and a few produced even less then stock clamping load,.
This is a absolute , and detailed scientific process .
Now ARP 2000 heads studs produced absolutely consistent clamping loads , and with in ½ of 1 % repeatability. If your going to make power , the first money spent should be on improved fasteners.

Also there are other methods then a torque wrench to install studs , its call torque angel. ARP provides the specs to people that ask. But it will involve a special tool. It is in no way the same as torque to yield methods use on stock head bolts If you have the tool and want the specs , PM me
 
COMP461 said:
Stock torque to yield bolts are designed to have a fairly forgiving range of install specs that yields consistent clamping load . That are installed with a mass production machine that torques all the studs at the same time . Cheap , reliable in their range .
ARP did the research , and it was a very extensive process. The results were on another thread , all over the map. You might get a few bolts to acheave more torquer , a few more yielded as designed , and produced no more then stock, and a few produced even less then stock clamping load,.
This is a absolute , and detailed scientific process .
Now ARP 2000 heads studs produced absolutely consistent clamping loads , and with in ½ of 1 % repeatability. If your going to make power , the first money spent should be on improved fasteners.

Also there are other methods then a torque wrench to install studs , its call torque angel. ARP provides the specs to people that ask. But it will involve a special tool. It is in no way the same as torque to yield methods use on stock head bolts If you have the tool and want the specs , PM me
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Not saying that ARP's aren't good(iv used them for years!), but when a company is selling a product, do ya think their findings are going to be anything but that their product is better... and what they are replacing is not adequate...no... They wouldn't sell their product! An out side test that didn't involve ARP would be WAY more impressive!!!
 
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ARP dose this kind of testing to build the best possibility fastener in the racing world . The fact that ARP studs are the mainstay in 100% NASCAR , NHRA Top Fuel , Funny Car , Pro Stock, and a good portion of F1 is a testament to the relentless drive to build the best possible high performance fastener in the world. Another fact is that no one out side of ARP has this kind of testing equipment
 
COMP461 said:
ARP dose this kind of testing to build the best possibility fastener in the racing world . The fact that ARP studs are the mainstay in 100% NASCAR , NHRA Top Fuel , Funny Car , Pro Stock, and a good portion of F1 is a testament to the relentless drive to build the best possible high performance fastener in the world. Another fact is that no one out side of ARP has this kind of testing equipment
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Like i said...not cutting on ARP's product, They are great!!! And yes their other companies that can do this kind of testing!
 
Torque "angels" are simply a method of measuring the stretch of a bolt. Consider that tightening a bolt requires an amount of stretch to keep the given item locked in place. Like a lock washer. While measuring torque is roughly the equivilent of measuring an inexact friction process, torque angles applies the principles of the stretch of the threads on a given bolt in their respective tensil strength range. For most all of us, if a torque wrench is used properly, which they seldom are, the results are very effective.
If you are serious about knowing more on the subject it is easily available. It is refered to as a logarithmic rate method.
 
03kbcobra said:
Torque "angels" are simply a method of measuring the stretch of a bolt. Consider that tightening a bolt requires an amount of stretch to keep the given item locked in place. Like a lock washer. While measuring torque is roughly the equivilent of measuring an inexact friction process, torque angles applies the principles of the stretch of the threads on a given bolt in their respective tensil strength range. For most all of us, if a torque wrench is used properly, which they seldom are, the results are very effective.
If you are serious about knowing more on the subject it is easily available. It is refered to as a logarithmic rate method.
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what do you consider the proper way to use a torque wrench?

slow steady pull?

thanks
 
Who here has experience with 15 dollar harbor freight click-stop torque wrenches? I'd guess that accuracy with them is non-existent!
 
I think the biggest error people commit with torque wrenches is properly 'warming' them up. My shop has torque wrench calibration equipment, and you'd be surprised how much difference it makes. To 'warm' a torque wrench up, simply set the wrench to its max torque setting, and break it over 3-5 times...lots of people just weld sockets to a plate and bolt it to their bench- you'll want something sturdy. On my craftsman torque wrenches, I think I saw about 10lb/ft difference at 150lb/ft setting between actual and indicated values when I took it straight out of the box and onto the machine.
Speaking of craftsman torque wrenches- I would reccommend their cheaper click-type wrenches. I bought mine a few Christmases ago when they were $50/piece, and I tested them at a littler better than their rated 4% accuracy.

I'm not saying I'm an expert by any means with torque wrenches- I don't even work on calibrating them. It's not my specialty. I just wanted to check mine when I bought them, so my shop chief showed me and let me know a few pointers.
 
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