TTY bolts? (Solution)

A torque to yield fastener (TTY) or stretch bolt is a fastener which is torqued beyond the state of elasticity and therefore undergoes plastic deformation, causing it to become permanently elongated.

Where are TTY bolts used?

Today, TTY fasteners are employed for bolted joints in a variety of automotive components, such as ball joints, knuckles and tie rods. Most of the applications are aluminum. However, TTY fasteners also are used on steel components, because they create a more consistent clamp load on the bolted joint.

What happens if you reuse TTY bolts?

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.

Which LS bolts are tty?

Which LS Fasteners are TTY? On a GM LS engine, the cylinder head bolts are TTY and cannot be re-used. The connecting rod bolts are also TTY, but can be tightened up to three times for bearing checking. The balancer bolt is also a torque-to-yield fastener.

Are ARP bolts TTY?

No, ARP bolts are not torque to yield (TTY). TTY fasteners, when being torqued, actually stretch because of the elastic properties of the material. This gives them the needed clamping force, but the downside it that they aren’t reusable (well, at least they shouldn’t be reused).

Why are TTY bolts used?

Torque to Yield (TTY) fasteners are used in many modern engines. When torqued properly, they provide better clamping force than standard fasteners. When swapping heads or rebuilding an engine, always replace any TTY bolts with new ones.

What is torque angle?

Put into its most simple terms, torque angle replaces a maximum torque value for a fastener with a specific amount of fastener rotation. After setting a low baseline torque, just to make sure the fastener is set, the fastener is rotated a precise amount to set the final position and clamp load.

What grade are TTy bolts?

The TTy bolts you will get from GM (or any pedders dealer) will be of the metric grade 10 variety, and they will have blue loctite on them. So yes, if you can find the exact same size bolts in a 10.9 locally, you can use them.

How do you tell if a bolt has yielded?

Answer: Simply screw a nut on the previously used bolt’s thread to the head on a fully threaded bolt or to the thread runout on a bolt with a full diameter body. If a nut will not screw on the entire bolt thread length, the bolt has yielded and it is not safe to be reused.

Can bolts be torqued more than once?

Mechanically, bolts may be reused provided the bolt never exceeded its yield point: a simple enough definition, but one that is more complicated than it may appear. This is because it is nearly impossible to verify if a bolt has ever been tensioned past the yield point.

Can u reuse LS head bolts?

A head bolt should not be reused if the threads are galled or badly damaged. Chasing damaged head bolt threads with a die will clean up the threads but also remove material (metal) and undermine the head bolt’s ability to torque down and hold to specs.

Can I reuse my rocker arm bolts?

Like head bolts you can reuse once but rocker bolts you can reuse up to 4 times.

Can you reuse LS head gaskets?

In a mock-up situation, it is perfectly acceptable to install, check clearances and reuse the gasket. Once heat is put to the gaskets, the ‘spring’ is gone and since the embossment is the sealing area, there is a greater chance of a coolant or compression leak.”

Are head studs TTY?

TTY is an attempt to eliminate the once common head bolt re-torque after the first use. This TTY allows a seal when a gasket relaxes – because the bolt will keep the same clamping force with slight gasket collapse.

Why are head studs better than bolts?

Studs provide the ability to obtain much more accurate torque values because the studs don’t twist during tightening as do bolts. Because the studs remain stationary during nut tightening, the studs stretch in one axis alone, providing much more even and accurate clamping forces.

Can you reuse 6.0 ARP head studs?

Are ARP bolts and studs re-usable? Yes. As long as the fasteners have been installed and torqued correctly, and show no visible signs of damage, they can be re-used. If they show any signs of thread galling or corrosion, they should be replaced.

What is a TTY bolt?

Modern engines employ torque to yield (TTY) fasteners in a variety of configurations. The clamping power provided by these fasteners is superior to that of ordinary fasteners when properly torqued. All TTY bolts are only intended for a single usage. Some rod bolts and main cap bolts, on the other hand, can be tightened up to three times throughout the assembly process. (Please refer to your service manual for precise information.) Whenever you are switching heads or rebuilding an engine, make sure to replace any TTY bolts that are damaged.

Why can’t they be reused?

TTY fasteners are characterized by their elastic properties. In order to achieve a specified ‘yield zone,’ they are intended to stretch. When the fastener is appropriately torqued, it functions like a spring, applying consistent clamping force to the workpiece. The stretch, on the other hand, is permanent. Once they have been torqued, they will never be able to return to their previous state.

How are they identified?

A bolt that has been treated with TTY will have its final torque specification listed as an angle in degrees rather than in foot-pounds.

What engines use them?

TTY fasteners are found on the majority of contemporary engines, including:

  • Engines from Chevrolet (LS and LT)
  • Ford Modular V8
  • Chrysler Gen. 3 Hemi

Do they require special tools?

TTY fasteners will require a first setup with a standard Torque Wrench after they have been installed. The final adjustment is achieved with the use of a Torque Angle Gauge.

Can I replace them with a reusable bolt?

ARP Bolts or Studs of excellent quality should be used in place of any TTY fasteners that are damaged.

Torque-to-yield (T‑t-y) Bolt Specification & Installation

The nature of bolts is that they are elastic, which means that, within their elastic range, they will expand as the strain on the bolt rises. It will return to its original length after the torque is released as long as the bolt is not stretched above its proof load (the highest force that a bolt can sustain while still acting elastically). Conventional bolts, on the other hand, can provide a problem when used on aluminum heads because the expansion velocity of this type of head can cause conventional bolts to be stretched above their yield point.

Traditionally, a torque specification is a number that has been calculated.

Because of the increased combustion pressure in today’s engines, larger clamping forces are required, which cannot be produced with the standard small diameter bolts that are often found in these engines.

Keep in mind that bolt stretch is the method by which we achieve the maximum clamping load.

Torque-To-Yield Bolts

Frequently used by many manufacturers, particularly on engines with aluminum heads and in conjunction with Multi-Layer Steel (MLS) head gaskets, T-T-Y (Torque-to-Yield) head bolts are designed to stretch within a specified yield zone when subjected to a predetermined amount of torque. As soon as they reach this zone, they are able to maintain a more precise and constant degree of clamping force throughout the whole mating surface of the head and block. They are stretched into their elastic range, and in many cases the strain exceeds the bolts’ elastic limit, causing them to become permanently bent.

By rotating the bolts a specific number of degrees and placing the fasteners in the yield zone, you can account for ‘clamp load scatter,’ or variations in clamp load caused by factors such as the type of assembly lubricant used, the condition of the bolt and bolt hole threads, and the surface finish of the fasteners.

Torque To Yield Bolts – (TTY) – What Exactly Are They

Torque to Yield Bolts – (TTY) – Torque to yield bolts are a type of bolt that has a high yield point. What Do They Do, Exactly?

Torque to yield bolts, are exactly what they sound like.

When a shop manual specifies that a bolt should be discarded and that fresh bolts should be used, the bolts in question are usually often torque to yield bolts. Purchasing new bolts may appear to be a pricey endeavor. After all, the ancient bolts still appear to be in fine condition, but appearances may be misleading. The practice of reusing old fasteners might result in a costly engine failure. In order to produce the consistent clamping force required by today’s engines, only new bolts must be used.

So, Why Do We Need These, Torque To Yield Bolts, Now?

In the 1960s and 1970s, we didn’t have a need for them! The short explanation is that engine materials are distinct from other materials. A difference between aluminum cylinder heads and cast iron cylinder blocks is that aluminum cylinder heads expand more quickly. While a result, as an engine warms up, pieces that are fastened together must move against each other or slide against their gaskets.

Therefore, the elastic properties of the torque to yield bolts, allow movement between parts; yet maintain even clamping loads and sealing.

Engine components are likewise far lighter today than they were a few decades ago. Heavy cast iron components were able to resist small fluctuations in torque without breaking down. As a result, thin-walled castings and aluminum alloys, which are often used nowadays, need exceedingly precise torque measurements, lest warping and leaks occur.

Common Installation Instructions

When describing the initial phase in the tightening process, a torque value is typically used; however, this is merely done to establish a standard baseline from which the genuine load may be applied. This is referred to as a preload or a tight torque in certain instances. An example of a tightening specification for torque to yield bolts might look something like this:

  • Tighten uniformly in succession over numerous passes to? Foot Lbs. Tighten in sequence? °
  • Tighten in sequence even more? °
  • Tighten in sequence even more?

This procedure ensures that friction, does not cause, uneven bolt loading.

Torque Angle Gauge (also known as a torque angle gauge) Bolts are by their by nature pliable. In other words, when the weight on the bolt grows, they will extend as long as they remain within their elastic range. When you put standard bolts on aluminum heads with a gasket that does not relax, such as a (MLS) gasket, you may have problems. Because of the expansion rate of aluminum heads, standard bolts will be stretched past their yield point and may shatter as a result. As a result, the necessity for torque to yield bolts arises.

Unfortunately, using a larger diameter bolt, is not the answer. Because, the larger a bolt is, the less it will stretch. Remember, bolt stretch, is how we get maximum clamping load.

It takes more power to get the bolt to start rotating than it does to keep it turning. The more stiction there is in the bolt, the more it might alter torque measurements. When threads are lubricated, they are more likely to glide smoothly; nevertheless, the lubricating characteristics of one lubricant are different from those of another. When torqueing a bolt, manufacturers will indicate what sort of lubrication, if any, should be used on the bolt. The clamping load will be affected if the incorrect lubricant is used.

Torque To Yield Bolts – Important Tip!

Consequently, the expansion rate of aluminum heads will cause standard bolts to be stretched past their yield point, causing them to shatter.

Furthermore, modern engines need the use of large clamping forces (due to increased combustion pressure). However, this is not possible with the smaller diameter bolts that are often used in engines. Thank you very much!

Torque-to-Yield Fasteners

TTY fasteners are now used in a range of automotive components, including ball joints, knuckles, and tie rods, to provide bolted joints for bolted joints. More information is available by clicking here. Traditional fasteners are torqued to a load that will slightly strain the bolt but will not cause it to overstretch over its yield point, as defined by the manufacturer. In order to maintain more constant clamp force on the joint, torque-to-yield (TTY) fasteners are stretched beyond the point of elongation.

  1. Historically, TTY fasteners have been the fastener of choice for bi-metal engines, in which two different metals – such as an aluminum head and a cast-iron block – must be clamped together in order for the engine to function properly.
  2. As a result, manufacturers devised a solution that included the use of TTY fasteners in conjunction with multi-layer steel head gaskets to absorb head lift.
  3. TTY fasteners are now used in a range of automotive components, including ball joints, knuckles, and tie rods, to provide bolted joints for bolted joints.
  4. TTY fasteners, on the other hand, are also utilized on steel components because they produce a more uniform clamp stress on the bolted connection than other fasteners.
  5. The greater the preload, the greater the amount of force that is delivered during this stretch.
  6. ‘When stretched to 0.0055 to 0.0060 inches, a normal 3/8-inch small-block Chevy rod bolt will yield around 10,000 psi preload,’ notes Robert Florine, president of ARP Fasteners.
  7. However, in many circumstances, the application is in a blind hole, and as a result, the clamp load is determined by the torque or applied force of the application.
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Whenever they reach this point, they’re supposed to bounce back and offer a more accurate degree of clamping force.

Once the yield zone has been achieved, the clamping force will become more constant and predictable.

According to Florine, TTY bolts used by OEMs are normally put by robotic equipment with a yield of 90 to 120 percent, depending on the application.

‘ When you modify the engine to any significant degree, though, it is asking for trouble.

Once a fastener has given, its capacity to deliver enough clamping force in a subsequent application has been severely impaired.

High-performance fasteners, on the other hand, may be overkill for stock applications.

Always keep the threads clean, since thread damage, corrosion, or rust can cause friction, resulting in an erroneous torque measurement.

Avoid over-oiling the bolts, especially if they’re threading into a blind hole, since this might cause them to fail. If there is too much oil in the system, the bolt will hydrolock and incorrect torque measurements will occur.

Torque to Yield Bolts

After using a normal bolt, a technician can twist the bolt to its yield point, and the bolt will return to its original shape and length when the bolt is withdrawn from the machine. It possesses elasticity, which means that it can be stretched and then returned to its original shape. This is not the case with bolts that require torque to give. There are two names that might be used to describe this occurrence. The first type of deformation is elastic deformation, and the second type of distortion is plastic deformation: 1.Elastic deformation: This is the amount of force or torque applied to a bolt while the bolt’s shape or length remains unchanged.

  • When the bolt has changed its shape and length, it has reached the point of elastic deformation, which occurs after the bolt has changed its shape and length.
  • As an illustration: Torque might be applied to an aluminum cylinder head in a number of steps ranging from one to 10.
  • This is the point at which elastic deformation takes place.
  • The bolt is now undergoing plastic deformation at this moment.
  • This is the point at which the bolt’s shape has been altered, and it must be replaced with a new torque to yield bolt if it is loosened or removed.
  • When using these bolts to clamp cylinder heads, proceed with caution.
  • TTY bolts are ubiquitous in late-model engines, and they are primarily used to hold the cylinder heads in place.
  • When a head gasket fails, coolant leaks into the combustion chamber, causing white-colored exhaust to be produced by the engine.

Ask Away! with Jeff Smith: The Truth Behind Torque-to-Yield Fasteners and Torque Angle Fastening

When a torque-to-yield bolt is used, what is the difference between it and a torque-angle bolt? I’ve seen that these bolts are being utilized with newer engines. Is it the same thing, or are they two different things? It’s also been brought to my attention that you shouldn’t reuse these bolts. Is that correct? Thank you, D.T. Jeff Smith (interviewer): Firstly and most crucially, let’s make a clear distinction between the topics we’re discussing. The torque-to-yieldbolt is your initial point of reference.

  • In this case, the first is a fastener and the second is a procedure.
  • Let’s dive into the specifics of torqueing fasteners and the important distinctions that exist between the two methods.
  • Let’s start by considering what we are attempting to accomplish by tightening a fastener in the first place.
  • To precisely set a pre-determined load, the time-honored method has been to employ a torque wrench.
  • To ensure that the head gasket seals properly, the amount of torque applied to the fastener should be proportionate to the amount of load we wish to put to the gasket.
  • This is accomplished by first eliminating friction between the threads of the block and the threads of the bolt, and then friction between the cylinder head and the bottom of the bolt’s head.
  • The amount of friction caused when tightening the fastener is dependent on a number of different factors.
  • In addition, using a moly lubricant can have a significant impact on this figure.
  • To illustrate why only 10 to 15 percent of the torque supplied to a bolt is utilised to provide the anticipated clamp force, consider the following example: The remainder (about 85 percent) is necessary for frictional resistance.
  • Putting this into practical terms: If the right load on a head bolt requires 65 ft-lbs of torque, then only 10 ft-lbs.
  • The remaining force (55 ft.-lbs.) is needed to overcome frictional resistance.

If there was a method to completely reduce friction, we’d just need to tighten the head bolts to 10 ft.-lbs., and the head gasket would seal without a hitch without any further effort. That should be enough to persuade you to pay attention.

This is a torque-angle gauge used on an iron block 6.0L engine. Once the initial torque spec is achieved, the fastener is then tightened to a specified angle like 60 or 80 degrees. In this case, the initial torque is 15 ft-lbs followed by an 80 degree turn of the breaker bar.

Pre-loading the bolt with the required amount of force is extremely crucial and is determined by the bolt manufacturer. When it comes to bolts, the combination of the strength of the material, the diameter, the thread, and the length all play key roles in determining the correct fastener stretch for the particular bolt. When a bolt is designed to tolerate a certain amount of pre-load while still returning to its original length, it is said to have achieved the intended stretch. You may conceive of a bolt in the same way that you think of a spring.

  • A bolt’s yield strength can be exceeded if it has been over-torqued and stretched past its limit.
  • When tightening fasteners such as head bolts, a method known as torque angle can be used to help overcome the large variability of friction that might occur.
  • If you’re working with torque angle, the first step is to create a precise starting point on the bolt by applying a little amount of torque to it.
  • Because friction is not a significant effect at this low level, the inaccuracy introduced by various lubricants is small.
  • The dial may then be simply adjusted to 0 degrees by placing the stop against a solid component of the engine so that it will not move when the stop is moved.
  • The torque-angle for the inner bolt is 80 degrees in the case of the LS main cap bolt with a preload of 15 ft.-lbs.
  • The clamp load is determined by neglecting the actual torque necessary to overcome friction and instead relying on the number of degrees.

Of course, if you change fasteners, such as switching from hex bolts to ARP bolts, the torque angle specification will no longer be valid because the ARP bolts are composed of a much stronger steel.

Because of the use of this lubricant, the amount of friction produced is significantly more exact and reproducible.

In addition to accuracy of the torque wrench, another factor that has a direct impact on typical torque values has to do with the torque wrench itself.

This is precisely how a torque wrench’s calibration is accomplished.

when the specification demands for 65 ft.-lbs.

Torque-to-yield (TTY) fasteners are an entirely distinct form of fastener that has become popular with 21stCentury engines due to their ability to give under high torque.

When stretched to a predetermined yield point, TTY fasteners are engineered to not exceed the clamp load limit.

This has the effect of stabilizing the strain on a head gasket, for example, while the engine is cold and then when the engine heats up – especially if the engine is made entirely of aluminum, in which case material growth is an issue.

This graph from Federal-Mogul illustrates why TTY fasteners can be far more efficient and apply better load than normal fasteners if employed properly. We do not know of any way to identify a TTY fastener by looking at it.

Because TTY bolts are meant to be used just once, they have the ability to provide a more constant clamp load at a higher cost. For example, GM LS engine head bolts are TTY fasteners, meaning that they can only be used once. If the bolt heads are removed, it is necessary to use new bolts to ensure that the right load is applied. As a result, aside from informing you about fasteners, the goal of all of this is to demonstrate that any bolt may be tightened with a torque-angle specification, but that does not imply that it is necessarily a TTY bolt.

  1. Engines have gotten significantly more complex in the twenty-first century, and this includes the way in which they are put together.
  2. Jeff Smith is the author of this piece.
  3. After earning a bachelor’s degree in journalism from Iowa State University in 1978, he decided to combine his two passions: automobiles and writing.
  4. The position of editor for Hot Rod magazine was his first job after graduating from college.
  5. Jeffrey Hassell has worked at Car Craft since 2003 in a variety of capacities (including as an editor).
  6. His contributions to OnAllCylinders have increased in frequency over time.

Torque-To-Yield (TTY) Cylinder Head Bolt Installation & Removal Tips

Automobile Repair Library, Auto Parts, Accessories, Tools, Manuals and Books, Car BLOG, Links and Index are some of the resources available on this website. byLarry Carley (c)2019 All rights reserved. Head bolts with a high ratio of torque to yield (TTY) are utilized on many late-model engines to secure the cylinder head to the block. TTY bolts are different from conventional head bolts in that they are meant to stretch somewhat when they are tightened down, as opposed to standard head bolts.

TTY head bolts also need less torque to be tightened than a normal head bolt, resulting in a more comfortable working environment.

Reduced blowby beyond the piston rings, fewer emissions, and improved compression are all benefits of rounder cylinder bores.

A TTY bolt may have a shorter shank (which allows it to stretch more readily) and be longer in length than a normal head bolt, depending on the application.

Many parts dealers can also check up your car and inform you whether or not it is equipped with TTY head bolts. It is also possible to utilize TTY bolts on the engine’s connecting rods as well as the crankshaft main bearing covers.


* Never use a torque-to-yield bolt more than once. The fact that the bolts are meant to be stretched only once means that stretching them a second time may lead them to be stretched past their yield point, resulting in the bolt breaking. They are one-time-use bolts, so dispose of the old ones and replace them with fresh ones. TTY bolts are often placed without the need of any tools. The threads of the bolts should not be lubricated or sealed with any oil, grease, or assembly lubricant. The reason behind this is because as a bolt is tightened, lubricants reduce friction, which reduces wear.

  1. * Before placing torque-to-yield head bolts in the engine block, clean the threads of the bolt holes in the engine block.
  2. Because of this, the bolts may become somewhat slack and may fail to properly seal the head gasket.
  3. When the bolt is tightened down, the washers assist in distributing the clamping load and preventing galling.
  4. It may be necessary to place a copper or steel shim beneath the head gasket in order to restore appropriate head height so that the bolts may be tightened properly.
  5. Applying torque to yield head bolts, rod bolts, and main bearing cap bolts should be done according to the manner prescribed by the vehicle manufacturer.
  6. In most cases, the bolts are tightened down in three to five steps, with each step increasing the amount of force applied to the bolts.
  7. * If a bolt breaks while you are tightening it, it is possible that you overstretched the bolt.
  8. Alternatively, you may have accidentally greased the bolt threads, causing the bolt to become overloaded.
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When removing cylinder head bolts that have been torqued to give, it is not uncommon for them to break due to the fact that they are meant for one-time usage only. That’s terrible news since that means you’ll have to drill out what’s left of the bolt from the hole in the block, as well as maybe repair any damaged threads in the hole. High mileage engines might suffer from rusted and corrosion-caused cylinder head bolts that become stuck. To assist release the threads prior to removing the bolts, use the following trick:* Placing a punch in the center of each head bolt, and then hammering each bolt a number of times will complete the task.

If a bolt continues to stick, use the punch and hammer to beat it many times.

Inspection of the holes in the block should be performed after the torque-to-yield head bolts have been removed. Purchase a fresh set of replacement bolts and check the length and threads to the original bolts to ensure that they are the same length and threads, then destroy the original bolts.

Related Articles:

Bolts for Cylinder Heads Wrench with a high torque rating (how to use) How to Disassemble Nuts and Bolts The Most Common Reasons for Head Gasket Failure Preventing Head Gasket Failures on a Repeated Basis More information on why head gaskets fail may be found here. Components of the OHC Cylinder Head Rebuilding an Engine: Some Suggestions More articles on engines may be found by clicking here. More information may be found by clicking here. Technical Articles on the Carley Automotive Website Make sure to check out our other websites as well: You Can Do Your Own Auto Repair Carley Automotive Software is a company that develops software for the automotive industry.

TTY Fasteners: Securing the Future

A significant portion of automotive engineering is being dominated by torque-to-yield (TTY) fasteners. They can be located on a variety of various sections of the automobile. In the case of TTY fasteners, they are mounting fasteners that have been torqued past the point of elasticity, and as a result, have become permanently extended. Ball joints and tie-rod ends are held together by a stud with a nut on one end and a washer on the other. They tighten the bolt until the stud is tensile, which binds the two pieces together.

Aluminum brake knuckles and cast iron engines were among the first bi-metal components to be clamped together using TTY fasteners in the 1950s.

Identifying TTY Ball Joints and Tie Rods

TTY studs are distinguishable by their inset hex head at the end of the stud, which allows them to be identified by sight. Always verify the service information to ensure that the correct amount of torque is applied to a suspension component, whether it is TTY or not.


If a ball joint or tie-rod is not properly placed, it might result in an accident. TTY fasteners should be installed dry. Do not oil, grease, or lubricate the bolt in any manner since doing so may cause the bolt to become overloaded and break when it is tightened. Use of an IMPACT DRIVER is strictly prohibited. EVER! If you use an impact driver to install a TTY fastener, it is possible that the parts you are installing it into will break and require replacement. When it comes to tightening down a TTY component, never assume.

Reusing TTY Items

Check with the manufacturer to determine if the component may be re-installed after it has been removed from service. Perhaps it is best to remove the control arm with the knuckle or separate the tie rods between the inner and outer shafts before removing the control arm.

arp head bolts or tty bolts?

1arp head bolts or tty bolts, which is better? 07-13-2010I’m about to put my heads back on and I’m thinking of getting arp head studs, but I’m not sure whether they’re worth it. I’m hoping I won’t have to remove the heads again, so I was thinking that ordinary head bolts would be sufficient. As a result, I’m asking, because I couldn’t find an answer when I searched for it. I’m assuming the rocker bolts are re-usable as well. 2Re: Are arp head bolts or tty bolts preferable? 07-13-2010 The TTY bolts are perfectly OK if you have no intention of ever removing the heads again; but, if you must remove the heads once more, the studs will have already recouped their cost in savings.

  • 3Are arp head bolts or tty bolts better for the job?
  • I’ll keep it in mind as I’m in the market for a coupler right now.
  • Summit Racing could have arp head bolt kits for l67s, which I’m looking into right now.
  • 07-13-2010 Yes, you will need to clean the holes in the walls.
  • 5Re: Are arp head bolts or tty bolts preferable?
  • I cleaned them with brake cleaner and then sucked them up with a shop vac.
  • 6Are arp head bolts or tty bolts better for the job?

It is not necessary to use a thread brush; the ideal method is to use an old head bolt and a die grinder to groove the threads down the length of the bolt in three or four lines, then thread them in and out.

Yes, it is time-consuming, but it thoroughly removes all of the goop in the proper manner.

07-13-2010 I’ll get back to you as soon as I can.

Is it possible to utilize a spin attachment on a dremel, though?

When I go home, I’m going to attempt the old stud trick.

9Are arp head bolts or tty bolts better for the job?

07-14-2010 If you intend to maintain your automobile, you should install head studs.

As previously said, the studs will pay for themselves.

Follow the directions in the ARP Box on how to install them, but don’t do so.

If you want to know the best practices for installing them correctly the first time, without causing any difficulty, please ask me when you receive them, or simply send me a private message.

~F~11 Is it better to use arp head bolts or tty bolts?

Interested in how I’m supposed to attach the headers, given how much the studs protrude from the body of the vehicle?

08-14-2010 13Re: Are arp head bolts or tty bolts preferable?

a small length on the outside and a long length on the interior Clean the threads in the block with a wire brush, and then twist the studs to 10 foot pounds.

I made certain that they were properly put.

The stud ARP box indicates that the hand should be tight!

08-15-2010 Did you take the time to clean the threads out of the head?

Fuel-guzzling 01 GTP with large cam and E85 in a 78 Dodge 2005 Cummins-Rollin Coal Engine Two Nipple General of the SMGPFC On the 15th of August, 2010, I received the following question: ‘Are arp head bolts better than TTY bolts?’ That is why I stated that I would not be following the ARP’s directions.

  1. First and foremost, the block and heads must be thoroughly prepared, including removing all of the old gasket and thoroughly degreasing and cleaning all of the surfaces.
  2. In my opinion, cleanliness is second only to holiness when it comes to engine construction.
  3. Thoroughly clean all of the threads in the block.
  4. With little to no effort, you can almost completely pursue it down by hand.
  5. Using Teflon Paste (NOT TAPE!) with a temperature rating of at least 500*F (check the back of your tube!) is the second option.
  6. About two pea-sized drops per hole should suffice.
  7. There are eight long and eight short, which are divided into groups of four long and four short on either side of the engine.

The LONG studs should be positioned towards the top/center of the engine, closer to the lifter valley, while the SHORT studs should be positioned lower, nearer to the headers, and then pre torque them to 10 pounds per foot.

6.) Manually brush away the Teflon paste that oozes out around each stud as it is threaded in; if there is any left over ooze, you did a good job and have enough Teflon paste in the container.

At this point, it should look something like this: A few weeks ago, I volunteered to assist with the assembly of this local engine.

8.) Attach the head to the block by carefully slipping it onto the block and placing it down lightly.

10.) The washers and nuts for the studs should be cleaned with brake cleaner, much like the studs, to ensure that they are degreased before use.

The nuts will have a small dab of moly lube applied inside each one so that when it is threaded on, the threads on the inside will be extremely thoroughly coated.

Thirteenth, the torque sequence and torque specks are as follows: Start with a low amount of torque for all of the nuts, then gradually increase the amount of torque until you achieve your goal torque.

I usually start with 40 ft.


This is the torque sequence for each head in your system.

We should make the above post a sticky since I don’t know how many times I’ve put all of that up on all of the different boards over the course of the past few decades.

08-15-2010 yup I followed the instructions in the section on how to prepare a report.

Fuel-guzzling 01 GTP with large cam and E85 in a 78 Dodge 2005 Cummins-Rollin Coal Engine SMGPFC General18Re: arp head bolts against tty bolts?


I suppose it will work if it does.

f19re: arp head bolts or tty bolts for the f19re?

Mine was perfectly sealed.

08-19-2010 According to what I’ve heard, the Ford engineers do this to their engines.

To be honest, I’d rather not deal with all of that cleanup and worry about the RTV setting up, as the paste will never become firm. The ability to choose between different heat cycles and temperature adjustments is a plus. ~F~

TTY bolts

TTY is an abbreviation for torque-to-yield. All bolts stretch a certain amount when they’re torqued, and then spring back a little when they’re untorqued; it’s similar to how a bungee cord behaves when it’s untorqued. When you add torque to steel, this is exactly how the material behaves in its natural state. A TTY bolt is designed to stretch to a particular extent and then spring back to produce an exact amount of clamping force that has been pre-determined in advance. When it comes to yield zone, the amount of stretch that may be tolerated necessitates that the torque directions be followed to the letter.

See also

Why newer engines need TTY bolts

Metal has the ability to expand and compress. Both the cast iron engine blocks and cylinder heads expanded and contracted at the same pace when they were constructed of cast iron. Newer engines, on the other hand, are constructed of aluminum alloys that expand and compress at various rates. When you install a new gasket, it will gradually become more relaxed over time as it ‘sets’ and compresses in the joint. If you depend only on torque during installation, the connection will weaken when the gasket relaxes, resulting in a loose connection.

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In contrast, a TTY bolt behaves more like a spring or bungee cord in that it has a certain window of ‘springiness’ that allows for expansion and contraction while still providing sufficient gripping strength.

The TTY torqueing procedure is a multi-step process

It is necessary to use both a torque wrench and a torque angle gauge while tightening a TTY bolt. You cannot twist these bolts unless you have both hands available, otherwise you risk destroying the bolt. Even worse, you’ll scuff up the head gasket and have to start from the beginning of the project. 1st step: tighten the bolt to the appropriate torque value. The second step is to attach a torque angle gauge to the bolt and turn it the specified number of degrees. Steps 34 and 35: This step may be followed by another torque step or by a second rotation step.

Some automobile manufacturers, on the other hand, permit re-use.

It is possible that you may shatter a TTY head bolt if you attempt to reuse it, or that you will ruin the head gasket work if you attempt to reuse a TTY head bolt that cannot be reused.

Purchase replacement head bolts.

How to torque a non-TTY head bolt

The torque of a non-TTY head bolt is displayed without an angle measurement. For example, the torque specifications ‘1st 22, 2nd 48’ are for a bolt that is not TTY. To torque the bolt to 22 ft/lbs, use a torque wrench. Then set your torque wrench to 48 ft/lbs and tighten to that level of torque.

How to torque a TTY head bolt

The following is an illustration of the torque method for a TTY head bolt: ‘First 29, second 90 degrees, third 90 degrees, NOTE: New bolts must be turned an additional 90 degrees.’ Here’s what it implies in practical terms: 1) Tighten the bolt to a torque of 29 ft/lbs. 2) Attach a torque angle gauge to the bolt and spin it 90 degrees. 3) After that, spin the bolt another 90 degrees. 4) If you’re using a fresh new bolt, you’ll need to spin it an extra 90 degrees after the third step. Other torque specifications may state something like: 56 in three stages, or something similar.

Set your torque wrench to 56 ft/lbs and tighten the bolt until it meets the specified tightness.

Remove the torque wrench for a little moment, then torque to the same 56 ft/lbs as the first time. Repeat the process a third time. What you’re doing here is allowing the head bolt to extend a little bit between each torque application effort.

Loosing and tightening pattern

It is possible that loosening the old head bolts at random will cause the cylinder head to distort. Similarly, tightening the cylinder head bolts in the incorrect pattern might cause the cylinder head to distort. Always adhere to the numerical pattern depicted here. The year is 2019. Rick Muscoplat is a professional musician. Rick Muscoplat posted a blog entry on

Trouble Shooter

I’m attempting to remove the cylinder head off a 4.2L Vortec 6-cylinder engine in a 2005 GMC Envoy, and I’m having some difficulty doing so. When I first started removing the head bolts, three of the six that I attempted to remove snapped off. At that time, I made the decision to stop. Is there something I’m doing wrong? Is there a certain technique to follow in order to remove these bolts? Are all of them going to need to be replaced once I’ve finally gotten the last one out? Tucson, Arizona’s John Stepp The Vortec engine, like the majority of contemporary engines, is fitted with torque-to-yield (TTY) head bolts.

  1. Instead of prescribing a torque number for bolt installation, the manufacturer specifies that these bolts be tightened using a torque plus angle approach to ensure that they are secure.
  2. Bolts are brought extremely near to their yield points when they are tightened in this manner.
  3. The little bending of the bolts provides them with the toughness they’ll need to maintain optimum compression of the gasket during thousands of heating and cooling cycles over the engine’s service lifetime.
  4. Particular care must be exercised when it comes to removing the TTY from the system.
  5. 05-06-01-026B).
  6. Chevrolet TrailBlazer and GMC Envoy models from 2002 to 2009.
  7. Oldsmobile Bravada (2002-2004) HUMMER H3 (2006-2009) Saab 9-7X (2005-2009) Inline Vortec engines with VINs 8, 9, 6, E and S and RPOs LK5, LLV, L52, LLR, LL8 are used in these vehicles, which had displacements of 2.8 to 4.2 liters.

Over time, the threads on the head bolts may get seized to the internal threads of the matching engine block.

GM’s answer to this problem is quite straightforward.

The vibration should be able to liberate the seized threads and aid in the effective removal of the seized threads.

Hand tools are all that are required to remove the remaining bolts, which should be done gently but confidently.

However, even with meticulous preparation and your best efforts, it is possible that some head bolts will fail.

Don’t be discouraged; General Motors provides an additional lifeline.

The following components are included in the kit: One 532 in.

reverse-twist drill bit (EN-47702-6); one 532 in.

reverse-twist drill bit (EN-47702-6); and one 532 in.

One drill pilot insert (EN-47702-1) with a double-ended design to ensure a straight drilling technique; In order to assure a straight drilling technique for bigger diameter head or main cap bolts (EN-47702-2), drill pilot inserts should be used.

The remaining bolt segment may be able to be removed by backing it out with a pick tool or the reverse-twist drill bit in this situation.

After all of the broken bolt pieces have been removed, the cylinder head must be thoroughly cleaned and prepared before it can be reinstalled.

Make use of a thread chasing tool, such as the one included with the EN-47702 package, to clean the threads.

It is not recommended to use oil or threadlocker on the bolts.

As a result of threads that have been polluted by trace amounts of dirt, antifreeze, or oil, the bolts will creak or shatter while being tightened.

Because of the enormous torque applied to these bolts, they will fail. Occasionally, extra cleaning with a non-residue cleaner such as a brake clean product, followed by drying with clean and dry compressed air, may be required in extreme circumstances. Obtain a PDF version of this document.

GM Tech Tip: Torque-To-Yield TTY Fastener Use And Reuse –

Fasteners with a torque + angle specification must be tightened to the torque portion of the specification first, then tightened further by adding the required angle to the torque portion of the standard. It is necessary to apply the angle in relation to the mating fastener. When tightening a fastener, the desired goal is to achieve an appropriate clamping force between the two elements of the assembly. When the vehicle is in operation and external forces are acting on the clamped pieces, the clamping force prevents the parts from becoming free.

The engineering team determines the approach to be utilized for a specific application, which is then stated in the service information.

Applying too much torque to the mating fastener might cause damage to the fastener and other mating components, as well as result in inadequate clamp load.

There are three different methods for the specification of tightening fasteners:

Torque is a term used to describe the force applied to a rotating object (T) Angle x Torque =? (TA) (TAY) is an abbreviation for Torque + Angle-to-Yield (also known as Torque-to-Yield (TTY)).


A typical torque wrench may be used to tighten a fastener that has a torque specification on the end of it. Unless otherwise mentioned in the service information, externally threaded fasteners (bolts, screws, and studs) that have been tightened according to this standard procedure can generally be reused.

Torque + Angle

Fasteners with a torque + angle specification must be tightened to the torque portion of the specification first, then tightened further by adding the required angle to the torque portion of the standard. It is necessary to apply the angle in relation to the mating fastener, if one is present, or in relation to the mating surface. If necessary, a backup wrench must be used to prevent the mating fastener from rotating while the angle specified by the torque + angle specification is applied to the fastener.

Torque + Angle-to-Yield

Fasteners with a torque + angle specification must be tightened to the torque portion of the specification first, then tightened further by adding the stated angle to the torque portion. It is necessary to apply the angle in relation to the mating fastener, if one is present, or the mating surface, if none is there. To prevent the rotation of the mating fastener from taking place while the angle is being increased, a backup wrench must be employed, if necessary, to prevent rotation from taking place.

Tightening in Stages

A fastener having a torque + angle specification must be tightened first to the torque portion of the specification and then tightened further by adding the required angle. The angle must be applied in relation to the mating fastener, if one is present, or in relation to the mating surface, if one is not there. If necessary, a backup wrench must be used to prevent the mating fastener from rotating while the angle is being added to the fastener in accordance with the torque + angle specification.

Unless otherwise mentioned in the service information, externally threaded fasteners that have been tightened according to this standard procedure can often be reused.

Reusing the Fastener

Take into consideration that an externally threaded fastener (bolt, screw, or stud) functions as a spring. In addition to the threads being tightened, the spring is also being stretched. When a traditional torque or torque + angle tightening specification is used, the spring returns to its original length when the torque or angle tightening specification is used. For tightening specifications including torque plus angle-to-yield, the spring is overstretched (plastically deformed) and does not return to its original length.

Mitchell1 has graciously provided this image.

TTY bolts vs studs

MY99TAWS6 had first posted this. Lots of threads on the arp head bolts and studs, as well as videos of people using them successfully, have been posted on YouTube. In the case of a FI engine, especially one that is running greater boost, I’m not sure why you would want to try to run torque to produce stock bolts. They perform admirably in low-boost situations. 5 to 8 psi, or even 10 psi. If the pressure is more than 10 psi, arp bolts or studs should be used. Basically, I’m going to be designing an engine that can withstand high boost pressures.

Using the little knowledge I had recalled, I had planned to run TTY in my ‘boosted’ engine, which I had acquired recently.

This causes me to assume that I am mistaken.

LOLI realize that ARP has a high tinsel strength.

I’m willing to wager that the majority of FI engines will break a piston and then be rebuilt with studs to prevent this.

Here are a couple more quotes that illustrate why I’m so intrigued.

Most torque requirements include a 25 percent safety margin, which means that they may be overtorqued by 25 percent without causing harm.

They are intended to be tightened just until the yield point is reached, but not to the point where the metal becomes twisted.

The disadvantage is that they can only be used once before they expire.

In the event that a standard fastener is used in their place, the clamping force will be 25 percent less effective.


TTY head bolts, in contrast to regular head bolts, are meant to deform – but only in a regulated manner.

However, once the yield point has been reached, the bolt is permanently stretched and will not return to its previous length.

What is the purpose of purposefully stretching the head bolts?

In addition, because variations in friction between bolts always result in some uneven loading, stretching the bolts ensures that all of the bolts apply equal clamping force no matter what value of torque is displayed on the wrench.

The result is improved cylinder sealing, longer head gasket durability, and less cylinder bore distortion (for reduced blowby and more power).

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