Do you replace old LS1 head bolts?
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Do you replace old LS1 head bolts? ....the last tear down on an LS1 that I did 10 years ago, I bought new head bolts from a GM dealer in Westchester county NY.
The parts guy laughed at me. He said the dealership has been re-using old head bolts for years and they have never had a single issue.... he said my purchase of new bolts was a waste of money - around $50.
Consequently, I am planning to reuse the old head bolts, if I need to tear off the heads....
Any thoughts?
The parts guy laughed at me. He said the dealership has been re-using old head bolts for years and they have never had a single issue.... he said my purchase of new bolts was a waste of money - around $50.
Consequently, I am planning to reuse the old head bolts, if I need to tear off the heads....
Any thoughts?
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From: Hurley, VA
I wouldn't do it. Google what a torque to yield bolt really is and you'll see why. When the bolt is torqued it stretches creating a spring/loaded type effect. Once their stretched and re used they don't do that anymore.
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...did that.... When did TTY bolts become popular? I believe it was around the same time as aluminum blocks.... LT1 cast iron block motors did not have these; right?
...bye the way, non-TTY bolts also stretch, and are made of similar metal so I'm a tad confused about the "new" technology.
...bye the way, non-TTY bolts also stretch, and are made of similar metal so I'm a tad confused about the "new" technology.
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From: Hurley, VA
I read about it on wikipedia I believe. I haven't messed with LT's very much but I know the early 2000's cavaliers used the TTY bolts and they were a aluminum head/iron block. The 6.1 Challengers are also TTY we've got a procharged one doing heads/cam on now and its a iron block. So I'm going to say late 90's is when it all happened.
Staging Lane
Joined: Apr 2014
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I change head bolts they are only like 30 for both sides on summit, these bolts are long and had threAdlock when you break them loose they feel flimsy after from stretching, I never reuse head bolt or connecting rod bolts just for safe precaution, to each his own
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From: Marengo, Ia
I think that makes reason 47385 I don't like people I don't know working on my cars.
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Rick Anderson: Posted on Friday, January 14, 2011 9:30 AM
Torque-to-yield (TTY) head bolts are designed to stretch when used. Once stretched, they are not as strong as before. Consequently, they cannot provide the same amount of clamping force and may break or shear off if reused.
The TTY bolt-tightening procedure is designed to provide a better, more uniform seal. On the factory assembly line, sophisticated torquing equipment is used to tighten head bolts beyond their yield point. This stretches the bolt slightly and evens out the loading so each bolt provides almost exactly the same amount of clamping force on the head gasket.
Because the tightening procedure permanently stretches the bolts, there is a risk of breakage if reused. Since there is no way to tell how many times such a bolt has been reused, most aftermarket gasket manufacturers say the risks of reusing TTY head bolts far outweigh replacement cost. For that reason, new TTY head bolts are often included in head gasket sets.
Torque-to-yield (TTY) head bolts are designed to stretch when used. Once stretched, they are not as strong as before. Consequently, they cannot provide the same amount of clamping force and may break or shear off if reused.
The TTY bolt-tightening procedure is designed to provide a better, more uniform seal. On the factory assembly line, sophisticated torquing equipment is used to tighten head bolts beyond their yield point. This stretches the bolt slightly and evens out the loading so each bolt provides almost exactly the same amount of clamping force on the head gasket.
Because the tightening procedure permanently stretches the bolts, there is a risk of breakage if reused. Since there is no way to tell how many times such a bolt has been reused, most aftermarket gasket manufacturers say the risks of reusing TTY head bolts far outweigh replacement cost. For that reason, new TTY head bolts are often included in head gasket sets.
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