fswiki.us - User contributions [en]

Threaded Fasteners

2023-09-16T03:50:28Z

TheoCamilleri: Added details to nyloc and distorted nut sections.

Threaded fasteners used in FS are most typically made of steel but are sometimes also made of stainless, titanium, or aluminum.
=Standards=
There are two main threaded fastener standards: metric and inch. Within these two categories lay additional standards set by various organisations. These standards may are often intercompatible but can differ in head size, strength, alloy, coating, pitch, and local avaliability. Teams that use both (e.g. a team in the U.S. with metric fasteners for the engine and inch fasteners for the rest of the car) should be extremely careful not to mix up the fasteners as certain metric/inch fasteners can thread with each other and compromise a bolted joint.
==Metric==
Metric screws are listed in the following way:<code><nowiki>M6x25 x 1mm Class 8.8</nowiki></code>. The M6 referes to the major diameter being 6mm, 25: the shaft length is 25mm, and the pitch is 1 thread per 1mm. A class 8.8 bolt is a medium strength steel bolt with a tensile strength of about 800MPa and about 80% of that being the yield strength.
===ISO===
Wikipedia [https://en.wikipedia.org/wiki/ISO_metric_screw_thread ISO Metric Screw Threads] has tables listing preferred sizes, and pitch.
==Inch==
Inch screws are listed in the following way:<code><nowiki>1/4-20 x 1 Grade 5</nowiki></code>. The 1/4 is the major diameter of 1/4in, a thread pitch of 20 threads per inch, and a length of 1in. A grade 5 bolt is a medium strength steel bolt with a tensile strength of about _ksi and a yield strength of _ksi.
===SAE===
[grades, charts, etc...]
===NAS===
NAS Shear bolts are often used in suspension systems because of their tight diameter tolerances, which means less compliance.
=Screw Types=

{| class="wikitable"
|-
|Photo
|Names
|Description
|-
|[[File:hexhead_mcmaster.png|50px]]
|Hex head
| 
|-
|[[File:12point_mcmaster.png|50px]]
|Twelve point
| 
|-
|[[File:sockethead_mcmaster.png|50px]]
|Socket head

Allen® head
| 
|-
|[[File:shoulder_mcmaster.png|50px]]
|Shoulder screw
| 
|-
|[[File:setscrew_mcmaster.png|50px]]
|Set screw
| 
|-
| 
|Quarter turn

[https://www.southco.com/en-us/product/hierarchy.html?hid=7345 DZUS® fastener]<ref>https://en.wikipedia.org/wiki/Dzus_fastener</ref>
|A specialty fastener that allows quick installation and removal of [[Body Panel|body panels]].
|}

===Reduced Loadability===
Countersunk, button head, and low profile bolts have weaker heads than hex head or socket head bolts, which can cause them to fail at the base of the head instead of the shank, and at lower load then the shank could withstand. The ISO/DIN standards state that the metric bolts will have "reduced loadability" of 80%, and will be labeled with a "0" before the class. ie. Class 08.8, 010.9, or 012.9.
* '''Countersunk head''': The title of table 3 from ISO 10642:1997(E) states "Minimum ultimate tensile loads (...) 80% of the values specified in ISO 898-1"
* '''Low Profile Socket Head''': The title of table 3 from DIN 7984 states "Minimum ultimate tensile loads (...) 80% of the values specified in ISO 898-1"
* '''Button Head''': The title of table 3 from ISO 7380: states "Minimum ultimate tensile loads (...) 80% of the values specified in ISO 898-1"

=====Caution:=====
There are many countersunk, button head, and low profile bolts produced that are
* '''not''' made according to one of the aforementioned standards. If they are not advertised as conforming to one of those standards, then their load capability cannot be confirmed (Or look up the standard they are made to).

* '''not''' made to a strength standard. These will not have 08.8, 010.9, or 012.9 etc printed on the head.

Also note that the Formula SAE / Formula Student rules may prevent countersunk, button head, or low profile bolts in certain locations.

=Nut Types=
===Hex Nut===
===Weld Nut / Riv-Nut===
==Locknut==
Locknuts resist loosening. Other methods can be used to resist loosening: [[Washer#Lock washer|lock washers]], [[Safety Wire|safety wire]], [[Locking Adhesive|locking adhesive]], or design. Most locknuts are only designed to be installed a few times otherwise their loosening resistance is diminished. Locknuts that rely on a prevailing torque, such as nylocs or distorted thread nuts, can effect the torque required to reach a desired bolt preload.
{| class="wikitable" style="width: 1661px;" data-mce-style="width: 1661px;"
|-
| style="width: 39px;" data-mce-style="width: 39px;"|Photo
| style="width: 106px;" data-mce-style="width: 106px;"|Common Name
| style="width: 1476px;" data-mce-style="width: 1476px;"|Description
|-
| style="width: 39px;" data-mce-style="width: 39px;"| 
| style="width: 106px;" data-mce-style="width: 106px;"|Jam nut
| style="width: 1476px;" data-mce-style="width: 1476px;"| 
|-
| style="width: 39px;" data-mce-style="width: 39px;"| 
| style="width: 106px;" data-mce-style="width: 106px;"|Nylon nut
| style="width: 1476px;" data-mce-style="width: 1476px;"| 
|-
| style="width: 39px;" data-mce-style="width: 39px;"| 
| style="width: 106px;" data-mce-style="width: 106px;"|Nyloc/Nylon Insert Nut 
| style="width: 1476px;" data-mce-style="width: 1476px;"|These nuts use a nylon collar to increase friction with the mating thread. As they rely on nylon to provide the prevailing torque, their maximum use temperature is limited to <100-120°C. FSAE/FS rules may prohibit use of nyloc nuts in high temperature locations. Re-use of nyloc nuts depends on the appropriate regulations, but generally they can be re-used, provided the prevailing torque is still sufficient. 
|-
| style="width: 39px;" data-mce-style="width: 39px;"| 
| style="width: 106px;" data-mce-style="width: 106px;"|Distorted nut

Stover nut

K-nut / Jet-nut
| style="width: 1476px;" data-mce-style="width: 1476px;"|Different components of the nut can be distorted to prevent loosening. For example: thread pitch and eccentricity. The temperature range is limited only by the parent metal or its plating and can be reused approximately 10 times before its locking capability is diminished<ref>Barrett, Richard. [https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19900009424.pdf|"Fastener Design Manual"], Nasa Reference Publication 1228 (1990) pp7</ref>. A K-nut or Jet-nut is ideal for high temperature applications. These types of locknuts may strip coatings/platings off of and wear down the threads of the mating bolt. When the prevailing torque has diminished, the bolt should also be replaced. 
|-
| style="width: 39px;" data-mce-style="width: 39px;"|
| style="width: 106px;" data-mce-style="width: 106px;"|Castle nut
| style="width: 1476px;" data-mce-style="width: 1476px;"|
|}

==Threaded Insert==
Threaded inserts are used to either repair a damaged set of threads, to create a stronger bolted joint in relatively weak materials like magnesium & aluminum, or for bolted joints that will be frequently assembled and dis-assembled. Cast aluminum parts are especially prone to being stripped when torqued, as a FSAE team will likely assemble and disassembled components such as engine casings far more frequently (and roughly!) than the manufacturers predict. Therefore, a set of helical thread inserts and associated tools are very useful for common fasteners like M6x1.0 screws for engines. Common types of threaded inserts include Helicoils, Timeserts and Keenserts. Typically, installation of a threaded insert requires a thread with a larger size than the bolt thread in parent object. Different size inserts are available based on the part's wall thickness and the required insert strength (when used to strengthen the bolted joint, larger inserts will result in a stronger joint). The male thread of a thread insert is often an uncommon thread form, and care should be taken to ensure the correct tap is used. The threaded insert is then screwed into the tapped hole and locked in place. The female thread of the threaded insert is the desired thread size.

Heat-set or heat-stake inserts can be used in parts made from thermoplastics, like FDM 3D prints. These inserts can be installed using a soldering iron, and are often used in plastic parts as a substitute for a tapped hole.
=Fastener Characteristics (how to choose)=

* Initial Tensioning
* Initial Tightening Force
** Brings bolt close to "proof load"
* Deformation of threads (pic)
* Maintenance schedule

=Torque=
Why torque a bolt? Create tension in the bolt which does the following:
* Prevent joint separation
* Reduces the cyclic stress that the bolt experiences during cyclic loading (at the cost of increases amplitude of the mean stress)
* Creates friction forces between the materials being clamped. The friction force can transmit shear forces, so the bolt itself isn't loaded in shear.

==Torque Accuracy==
The ultimate goal of torque is to tension the bolt. Unfortunately, torque is a very inaccurate method of achieving a specific tension. The tension can be off by +/- 25%.<ref name="NASA"></ref> It widely used because it is cheap to apply. When following a torque spec, be careful to follow the guidelines for assembling, as the use of lubricants such as engine oil can significantly change the measured torque for a given bolt stress (which is what you ultimately care about). NEVER try to guess torque by feel, no matter how experienced you are. A good torque wrench is essential, and torque wrenches that mechanically disengage when a dialed in torque is reached are nice to have.
==Calculate Torque==
The Fastenal Technical reference guide<ref name="Fastenal"> [http://www-eng.lbl.gov/~shuman/NEXT/MATERIALS&COMPONENTS/Pressure_vessels/FastenalTechnicalReferenceGuide.pdf Fastenal Technical Reference Guide]</ref> and the NASA Fastener Design Manual<ref name="NASA">https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19900009424.pdf NASA Fastener Design Manual</ref> (Pg 17 Alternative Torque Formula), and Shigley's<ref name="Shigleys">Budynas, Nisbett. Shigley's Mechanical Engineering Design 9th edition</ref> show the commonly used formula:

: <math>T=K*F*d</math>
Where
* <math> T </math> is Torque applied to the head of the fastener
* <math> K </math> is a Torque Coefficient related to friction. The Torque Coefficient depends on the materials, coatings, and lubricants (if present) of the connection. You can find a value from table VI of the Nasa manual,<ref name="NASA"></ref> or page 24 of the Fastenal Guide.<ref name="Fastenal"></ref>
* <math> F </math> is the preload tension force. Shigley's recommends <math>0.75 * F_{proof}</math> for non-permanent connections, where <math>F_{proof}</math> is the proof load of the bolt. Proof Stresses for common fasteners are listed in Shigley's, which can be used to calculate proof load. The tables in Shigley's show that proof stress is often 70%-80% of the yield strength of the bolt.<ref name="Shigleys"></ref>
* <math>d</math> is the diameter of the bolt.

=====Locknuts with Torque Calculations=====
Note that using nylon insert "locknuts" or prevailing torque nuts will increase the torque required for a given bolt tension. This torque is independent of the tension, so you can measure how much additional torque is required to overcome this locking feature, and simply add it on top of the calculation.
=====The Lazy Way=====
[https://www.fastenal.com/en/83/torque-calculator Fastenal Torque Calculator]
=Further Reading=

* [https://www.youtube.com/watch?v=f7qkHxG1v1E tarkka Fasteners Introduction Youtube Video]
* [https://www.fsaeonline.com/cdsweb/gen/DownloadDocument.aspx?DocumentID=5eafc7b3-b61d-470c-b929-7ad95d426d97 FSAE Online Series Resources: Threaded Fasteners for FSAE] If link breaks, it is found under fsaeonline.com > Series Resources > Design Event > Reference Documents.
* Machinerys Handbook
* [http://www-eng.lbl.gov/~shuman/NEXT/MATERIALS&COMPONENTS/Pressure_vessels/FastenalTechnicalReferenceGuide.pdf Fastenal Technical Reference Guide]
* [https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19900009424.pdf NASA Fastener Design Manual]
* Carroll Smith's ''Screw to Win''
* [https://www.mcmaster.com McMaster-Carr]
* Schaeffler Technical Pocket Guide (available in print or as an App)

=References=
<references /> 

[[category:Fasteners]]

Threaded Fasteners

2023-09-16T03:36:05Z

TheoCamilleri: /* Threaded Insert */

Threaded fasteners used in FS are most typically made of steel but are sometimes also made of stainless, titanium, or aluminum.
=Standards=
There are two main threaded fastener standards: metric and inch. Within these two categories lay additional standards set by various organisations. These standards may are often intercompatible but can differ in head size, strength, alloy, coating, pitch, and local avaliability. Teams that use both (e.g. a team in the U.S. with metric fasteners for the engine and inch fasteners for the rest of the car) should be extremely careful not to mix up the fasteners as certain metric/inch fasteners can thread with each other and compromise a bolted joint.
==Metric==
Metric screws are listed in the following way:<code><nowiki>M6x25 x 1mm Class 8.8</nowiki></code>. The M6 referes to the major diameter being 6mm, 25: the shaft length is 25mm, and the pitch is 1 thread per 1mm. A class 8.8 bolt is a medium strength steel bolt with a tensile strength of about 800MPa and about 80% of that being the yield strength.
===ISO===
Wikipedia [https://en.wikipedia.org/wiki/ISO_metric_screw_thread ISO Metric Screw Threads] has tables listing preferred sizes, and pitch.
==Inch==
Inch screws are listed in the following way:<code><nowiki>1/4-20 x 1 Grade 5</nowiki></code>. The 1/4 is the major diameter of 1/4in, a thread pitch of 20 threads per inch, and a length of 1in. A grade 5 bolt is a medium strength steel bolt with a tensile strength of about _ksi and a yield strength of _ksi.
===SAE===
[grades, charts, etc...]
===NAS===
NAS Shear bolts are often used in suspension systems because of their tight diameter tolerances, which means less compliance.

=Screw Types=

{| class="wikitable"
|-
|Photo
|Names
|Description
|-
|[[File:hexhead_mcmaster.png|50px]]
|Hex head
| 
|-
|[[File:12point_mcmaster.png|50px]]
|Twelve point
| 
|-
|[[File:sockethead_mcmaster.png|50px]]
|Socket head

Allen® head
| 
|-
|[[File:shoulder_mcmaster.png|50px]]
|Shoulder screw
| 
|-
|[[File:setscrew_mcmaster.png|50px]]
|Set screw
| 
|-
| 
|Quarter turn

[https://www.southco.com/en-us/product/hierarchy.html?hid=7345 DZUS® fastener]<ref>https://en.wikipedia.org/wiki/Dzus_fastener</ref>
|A specialty fastener that allows quick installation and removal of [[Body Panel|body panels]].
|}
===Reduced Loadability===
Countersunk, button head, and low profile bolts have weaker heads than hex head or socket head bolts, which can cause them to fail at the base of the head instead of the shank, and at lower load then the shank could withstand. The ISO/DIN standards state that the metric bolts will have "reduced loadability" of 80%, and will be labeled with a "0" before the class. ie. Class 08.8, 010.9, or 012.9.

* '''Countersunk head''': The title of table 3 from ISO 10642:1997(E) states "Minimum ultimate tensile loads (...) 80% of the values specified in ISO 898-1"
* '''Low Profile Socket Head''': The title of table 3 from DIN 7984 states "Minimum ultimate tensile loads (...) 80% of the values specified in ISO 898-1"
* '''Button Head''': The title of table 3 from ISO 7380: states "Minimum ultimate tensile loads (...) 80% of the values specified in ISO 898-1"

=====Caution:=====
There are many countersunk, button head, and low profile bolts produced that are
* '''not''' made according to one of the aforementioned standards. If they are not advertised as conforming to one of those standards, then their load capability cannot be confirmed (Or look up the standard they are made to).

* '''not''' made to a strength standard. These will not have 08.8, 010.9, or 012.9 etc printed on the head.

Also note that the Formula SAE / Formula Student rules may prevent countersunk, button head, or low profile bolts in certain locations.

=Nut Types=
===Hex Nut===
===Weld Nut / Riv-Nut===
==Locknut==
Locknuts resist loosening. Other methods can be used to resist loosening: [[Washer#Lock washer|lock washers]], [[Safety Wire|safety wire]], [[Locking Adhesive|locking adhesive]], or design. Most locknuts are only designed to be installed a few times otherwise their loosening resistance is diminished.

{| class="wikitable" style="width: 1661px;" data-mce-style="width: 1661px;"
|-
| style="width: 39px;" data-mce-style="width: 39px;"|Photo
| style="width: 106px;" data-mce-style="width: 106px;"|Common Name
| style="width: 1476px;" data-mce-style="width: 1476px;"|Description
|-
| style="width: 39px;" data-mce-style="width: 39px;"| 
| style="width: 106px;" data-mce-style="width: 106px;"|Jam nut
| style="width: 1476px;" data-mce-style="width: 1476px;"| 
|-
| style="width: 39px;" data-mce-style="width: 39px;"| 
| style="width: 106px;" data-mce-style="width: 106px;"|Nylon nut
| style="width: 1476px;" data-mce-style="width: 1476px;"| 
|-
| style="width: 39px;" data-mce-style="width: 39px;"| 
| style="width: 106px;" data-mce-style="width: 106px;"|Nylok
| style="width: 1476px;" data-mce-style="width: 1476px;"| 
|-
| style="width: 39px;" data-mce-style="width: 39px;"| 
| style="width: 106px;" data-mce-style="width: 106px;"|Distorted nut

Stover nut

K-nut / Jet-nut
| style="width: 1476px;" data-mce-style="width: 1476px;"|Different components of the nut can be distorted to prevent loosening. For example: thread pitch and eccentricity. The temperature range is limited only by the parent metal or its plating and can be reused approximately 10 times before its locking capability is diminished<ref>Barrett, Richard. [https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19900009424.pdf|"Fastener Design Manual"], Nasa Reference Publication 1228 (1990) pp7</ref>. A K-nut or Jet-nut is ideal for high temperature applications.
|-
| style="width: 39px;" data-mce-style="width: 39px;"|
| style="width: 106px;" data-mce-style="width: 106px;"|Castle nut
| style="width: 1476px;" data-mce-style="width: 1476px;"|
|}

==Threaded Insert==
Threaded inserts are used to either repair a damaged set of threads, to create a stronger bolted joint in relatively weak materials like magnesium & aluminum, or for bolted joints that will be frequently assembled and dis-assembled. Cast aluminum parts are especially prone to being stripped when torqued, as a FSAE team will likely assemble and disassembled components such as engine casings far more frequently (and roughly!) than the manufacturers predict. Therefore, a set of helical thread inserts and associated tools are very useful for common fasteners like M6x1.0 screws for engines. Common types of threaded inserts include Helicoils, Timeserts and Keenserts. Typically, installation of a threaded insert requires a thread with a larger size than the bolt thread in parent object. Different size inserts are available based on the part's wall thickness and the required insert strength (when used to strengthen the bolted joint, larger inserts will result in a stronger joint). The male thread of a thread insert is often an uncommon thread form, and care should be taken to ensure the correct tap is used. The threaded insert is then screwed into the tapped hole and locked in place. The female thread of the threaded insert is the desired thread size.

Heat-set or heat-stake inserts can be used in parts made from thermoplastics, like FDM 3D prints. These inserts can be installed using a soldering iron, and are often used in plastic parts as a substitute for a tapped hole.

=Fastener Characteristics (how to choose)=

* Initial Tensioning
* Initial Tightening Force
** Brings bolt close to "proof load"
* Deformation of threads (pic)
* Maintenance schedule

=Torque=
Why torque a bolt? Create tension in the bolt which does the following:
* Prevent joint separation
* Reduces the cyclic stress that the bolt experiences during cyclic loading (at the cost of increases amplitude of the mean stress)
* Creates friction forces between the materials being clamped. The friction force can transmit shear forces, so the bolt itself isn't loaded in shear.

==Torque Accuracy==
The ultimate goal of torque is to tension the bolt. Unfortunately, torque is a very inaccurate method of achieving a specific tension. The tension can be off by +/- 25%.<ref name="NASA"></ref> It widely used because it is cheap to apply. When following a torque spec, be careful to follow the guidelines for assembling, as the use of lubricants such as engine oil can significantly change the measured torque for a given bolt stress (which is what you ultimately care about). NEVER try to guess torque by feel, no matter how experienced you are. A good torque wrench is essential, and torque wrenches that mechanically disengage when a dialed in torque is reached are nice to have.

==Calculate Torque==
The Fastenal Technical reference guide<ref name="Fastenal"> [http://www-eng.lbl.gov/~shuman/NEXT/MATERIALS&COMPONENTS/Pressure_vessels/FastenalTechnicalReferenceGuide.pdf Fastenal Technical Reference Guide]</ref> and the NASA Fastener Design Manual<ref name="NASA">https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19900009424.pdf NASA Fastener Design Manual</ref> (Pg 17 Alternative Torque Formula), and Shigley's<ref name="Shigleys">Budynas, Nisbett. Shigley's Mechanical Engineering Design 9th edition</ref> show the commonly used formula:

:<math>T=K*F*d</math>

Where
* <math> T </math> is Torque applied to the head of the fastener
* <math> K </math> is a Torque Coefficient related to friction. The Torque Coefficient depends on the materials, coatings, and lubricants (if present) of the connection. You can find a value from table VI of the Nasa manual,<ref name="NASA"></ref> or page 24 of the Fastenal Guide.<ref name="Fastenal"></ref>
* <math> F </math> is the preload tension force. Shigley's recommends <math>0.75 * F_{proof}</math> for non-permanent connections, where <math>F_{proof}</math> is the proof load of the bolt. Proof Stresses for common fasteners are listed in Shigley's, which can be used to calculate proof load. The tables in Shigley's show that proof stress is often 70%-80% of the yield strength of the bolt.<ref name="Shigleys"></ref>
* <math>d</math> is the diameter of the bolt.

=====Locknuts with Torque Calculations=====
Note that using nylon insert "locknuts" or prevailing torque nuts will increase the torque required for a given bolt tension. This torque is independent of the tension, so you can measure how much additional torque is required to overcome this locking feature, and simply add it on top of the calculation.

=====The Lazy Way=====

[https://www.fastenal.com/en/83/torque-calculator Fastenal Torque Calculator]

=Further Reading=
* [https://www.youtube.com/watch?v=f7qkHxG1v1E tarkka Fasteners Introduction Youtube Video]
* [https://www.fsaeonline.com/cdsweb/gen/DownloadDocument.aspx?DocumentID=5eafc7b3-b61d-470c-b929-7ad95d426d97 FSAE Online Series Resources: Threaded Fasteners for FSAE] If link breaks, it is found under fsaeonline.com > Series Resources > Design Event > Reference Documents.
* Machinerys Handbook
* [http://www-eng.lbl.gov/~shuman/NEXT/MATERIALS&COMPONENTS/Pressure_vessels/FastenalTechnicalReferenceGuide.pdf Fastenal Technical Reference Guide]
* [https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19900009424.pdf NASA Fastener Design Manual]
* Carroll Smith's ''Screw to Win''
* [https://www.mcmaster.com McMaster-Carr]
* Schaeffler Technical Pocket Guide (available in print or as an App)

=References=
<references /> 

[[category:Fasteners]]

Engine

2022-09-19T01:21:16Z

TheoCamilleri:

The engine is the center of the internal combustion powertrain system. All other components of the greater system exist to service the engine in different ways. This means the engine is sensitive to design changes made across the entire powertrain. As of 2022, the FSAE rules require an internal combustion engine with a displacement of 710cc or less<ref>2022 fsae rules PDF: https://www.fsaeonline.com/cdsweb/gen/DownloadDocument.aspx?DocumentID=25e8885c-7397-4b2d-93b3-fc404960bab1</ref>. Available OEM motors within this displacement limit are largely sourced from motorcycles and snowmobiles. The purpose of an internal combustion engine is to convert the chemical energy in [[Fuel|gasoline]] or [[Fuel|ethanol]] into mechanical energy used to propel the car. The engine is one of the most complicated and often heaviest single parts of any vehicle.

''Please take a look at the outline in the discussion section before making changes to this page''

=Theoretical=
{{Main|Otto Cycle}}
=Structure=
Wikipedia does a very detailed explanation on general engine layout. This article will focus on motorcycle-style engines w.r.t. fsae competitions.

Engine configuration is a case where the 80/20 rule really applies: the last bit of effort really doesn't get you too much.
==Motorcycle Engines==
Motorcycle engines make up the vast majority of engines used in FS/FSAE. The structure and operation of motorcycle engines differs from typical car engines in a few key places: size, layout, redline bb. Engines used in these competitions are all under 150 lbs with 600cc 4 cylinders coming in at about 125-140hp, depending on brand or custom parts. Single cylinder engines typically weigh in the neighborhood of 70-90 pounds. These engines are almost exclusively overhead cam layout.
===Four Cylinder Engines===
These bike engines are supersport engines and already configured to power a motorcycle in the same weight range as most FS/FSAE cars at a high level (albeit with a bike transmission and unrestricted intake).
===Single Cylinder Engines===
crossflow cylinder discussion?
Yamaha yzf that have intake in front and exhaust in the rear - contrast to every other engine
==Snowmobile Engines==
==Other Engines==
=Engine Control=
{{Main|Engine control}}

Most modern engines are controlled by an engine control module (ECM) that determines when to inject the fuel and when to ignite the charge using various sensors and an engine tune.
=Goals=
The team's approach to the engine system is a balancing of multiple contradictory goals. With all else being held constant, running an engine at a higher power level will sacrifice some reliability and often efficiency. The balance struck is a critical design choice taken by the team.
==Reliability==
If the engine finishes endurance, it was reliable. (to some teams, to others, maybe they need one engine to last many years due to budget constraints or the fact that they're running an aprillia and there's only two in the US)

Michael Royce in Learn & Compete states that “[reliability] must be the number one technical objective of the team”.
===Engine Choice===
Engine to engine comparisons are difficult, and the literature is sparse at best. Most available engine specific reliability reports are anecdotal. However, brand comparisons are both easier and more widely available. Consumer Reports performed such a comprehensive study on motorcycle reliability<ref>https://www.consumerreports.org/cro/news/2015/04/who-makes-the-most-reliable-motorcycle/index.htm</ref>.

The reliability study is focused on how often the bikes would need to have repairs within the first four years of purchase. The three big Japanese motorcycle companies, Yamaha, Suzuki, and Honda, are the only three with under 15% of the bikes with repairs needed. Yamaha leads the brands with 11% compared to the 12% for Honda and Suzuki each. It is important to consider that this study included the bike as a whole, and that for all of the studied motorcycles “mechanical engine problems were relatively rare, with only 3 percent having trouble with the cylinder head or valvetrain, or with the crankcase, crankshaft, or pistons. Similarly, only 3 percent needed transmission repairs, although 7 percent had clutch problems.” LA Times <ref>https://www.latimes.com/business/autos/la-fi-hy-consumer-reports-motorcycle-ratings-20160127-story.html</ref> researching this study reported an interview stating "European bikes are engineered for character and sex appeal, and Japanese bikes are engineered for reliability,". This sentiment can be found echoed in the FSAE online forums.
===Servicing===
Another aspect of reliability is parts and tools availability. If something breaks, how easy is it to get hold of spare parts quickly in order to fix the engine? Do you need special tools to service the engine, and can you buy, borrow or manufacture these?
==Power & Torque==
All else being held equal, the car that produces more power will win the race. However, the primary function of the engine is to produce ''enough'' power to accomplish your designed team goals. Determining ''how much is enough'' is one of the fundamental questions to answer for the system. Additional questions are: At what RPM should we make peak power? Torque? To all of these questions, it depends heavily upon your team's design philosophy. All could be approximated from a rudimentary lap-time simulation, but will need to be confirmed via testing. There are a few ways to maximize engine power. These include, but are not limited to:
* Engine Choice
* Engine Modifications
* Spark and Fuel Tuning
* Auxiliary System Tuning (Intake, exhaust, etc)
I imagine there is a lot more to expand upon here - Novotny

Examples of teams design philosophy:
* we have a novice driver - we want our torque curve to be wide and flat
* we run a CVT and the engine will hold at a specific RPM during all events and we only want torque at that spot at the expense of all else
* we are a first year team and we dont know what we are doing so we are just going for peak torque everywhere
* we have the torque curve in the shape we want so we are just tuning for peak torque everywhere
* we are running with huge boost and need to run with an AFR of 9 or else we'll be building a bomb
* we can't get our engine to idle, so we're spending the whole year tuning at 1.5K RPM and didn't get around to anything else
* our driver is a 4th year masters student who has 8 years of FS driving and can put the engine wherever he wants, we are giving him peak torque at 9650 RPM because thats what gives him the fasted lap times during testing

Torque and power are determined by testing the engine on a dynomometer (need page for dynos).
==Power Limiting Factors==
====Restrictor====
[[Intake#Restrictor Power Limit Derivation|Restrictor power limit derivation]]
====Piston Speed Limit====
The competition limits the engine speeds allowed<ref>http://fsaeonline.com/content/Noise%20Test%20Speeds%202015.pdf</ref>.
a. Automotive / Motorcycle engines 914.4 m/min (3,000 ft/min)
b. Industrial Engines 731.5 m/min (2,400 ft/min)
The calculated speed will be rounded to the nearest 500 rpm.
==Efficiency==
high speed low drag babey
=Engine Modifications=

* To fill in, see note in editing for discussion points


=Simulation=
[[Otto Cycle|otto cycle]]

matlab sims for freshmen?

==1D engine sims==
Ricardo WAVE or GT-Power are commonly used. At the 1D level, simulations are good for understanding trends, but not necessarily getting a precise power number. These trends can help identify what changes to the system will have positive or negative impacts and to what extent they will change the output. Specific problems arise in the 1D models for the highly 3D behavior air achieves through the restrictor and plenum. The strength really lies in getting an engineering understanding of how to design an intake and exhaust for a given torque curve e.g. runner length, exhaust collector strategy (4-2-1 or a 4-1 exhaust), and plenum size.
==3D flame propogation sims in advanced research labs==
Just use a dynamometer or WAVE. 3D combustion CFD is really nasty and without experiments to support your model it is suspect.
=Oil System=
{{Main|Oil}}
=Mounting System=
Vibration Reduction
=Best Practices=
Engines can be incredibly robust to working conditions as long as they have air, compression, fuel, and spark. That being said, there are many places where a little love and care will reap huge benefits.

Many of the systems inside the engine operate on small tolerances. These tolerances mean it's wise to care for your engine, if you want it to last. Often, you can operate an engine outside of many of these tolerances, but you will lose performance and often risk severe damage to the components if not catastrophic failure.

When purchasing an engine, it is good practice to tear it down and inspect all parts for tolerance. If the engine is used, this is exponentially more important, as you will need to check for wear as well. Many teams (in the US) purchase used engines from motorcycle crashes, which can cause subtle damage to the internals, even if none is present on the outside of the engine.
==Servicing==
It will be well worth the investment to buy a service manual for the engine, or find a pdf online to print, and put together in a binder. If putting the pages in a binder, using plastic sleeves will protect the pages from oil damage. If using a book... be careful.

If the team is buying a used engine, perform a full engine teardown and service to ensure the engine is in full working condition.

'''Teardown'''
* Valvetrain
** Take the chance to measure your cams if you can for accurate simulations.
** Correct lashing
** Valve seating
* Head 
** check flatness, possibly deck
* Block
** Clean surface
** Check flatness, possibly deck
** Check cylinder roundness, if too far out of spec you'll lose a significant amount of power.
** Hone cylinders if changing rings, or if too shiny
* Pistons
** Clean faces
** check rod bearings for wear
** Check rings, likely good idea to replace if any blow-by on piston
* Crankcase
** Check for metal bits lol
* Get a new set of gaskets (MLS head gasket can likely be reused depending on condition)
* Get a new set of all TTY bolts

How/when to service.

How to diagnose issues.

Why combustion is more romantic than electric.

=Common Engines=
I think bc the cbr, r6, and a few of the 450s are so common, we can use this to list what we have done to optimize for FSAE use.

Example: gear removal, EWP, custom valving, suggested idles, mounting tips, weights/mass, stock water pump flow rates, oil recomendations, intake mounting recs. exhaust mounting recs, heat generation, wiring, injectors

Honda CBR 600RR
* remove first gear, breaks traction with any reasonable FDR
* max heat dissipation of ~10kW needed from cooling system (utoronto 2007<ref>https://manualzz.com/doc/35576578/design-and-optimzation-of-a-formula-sae-cooling</ref>)
* remove the thermostat control to keep temps down (this is something I am skeptical of. The thermal mass of the engine and cooling circuit is high enough that you won't get into trouble running the OEM thermostat if the cooling system operates correctly, and the engine is happier when it is at temperature. This is a relatively minor modification so running a lap with and without could be a decent test) 

Yamaha R6

Yamaha WR/YZ450
* WPI runs WiSECO high compression piston
* Be cognizant of the different generations of WR/YZ450F when buying engines and parts. Pre-2016 engines are 5 valve heads with the exhaust port on the front of the head, 2016+ are 4 valve with the exhaust port on the rear.
* Stock engine does not have bungs/take-offs for oil temperature or pressure. The filter cap is a convenient place to add a bung, as is the oil pressure check port.
* Oil pressure is often low compared to a street bike engine (CBR600RR, R6, etc.). Most of the engine bearings are roller bearings, so oil pressure will tend to be lower. 10-20 psi at idle and ~4-5 psi(both measured from the filter cap) under lateral acceleration seems to be common.
* Stock engine does not have a cam position sensor, however there is space on the valve cover to add one.
* 1st gear will likely be unusable for launching, depending on final drive. Consider the gearset from the other engine (ie: if you have a WR, look at a YZ gearset. If you have a YZ, look at a WR gearset).
* Many parts are common between the WR and YZ, with the main exceptions being the transmission gearset and the cams.
* Stock mechanical water pump will likely not provide enough mass flow for adequate heat rejection.
* Oil temperature may be difficult to manage. The WR/YZ450 engine family does not have an oil to water heat exchanger, heat rejection from the oil is through heat transfer into adjacent water passages.
* Starter geartrain seems to be strong enough for higher cranking loads seen in FSAE use (we ran a used engine with unknown history for a year and didn't have any issues with the starter geartrain breaking knock on wood).
* 2016 WR450F weighed 30.45 kg without oil or coolant. Oil was 0.61 kg and a stock engine sprocket was 0.09 kg.

see all engines [[List of Engines|here]]
=See Also=

* [https://drive.google.com/file/d/1Q5XaHZGjjahw5Ws1lvxdjKbLsm6vQtQK/view?usp=sharing UWaterloo Formula Motorsports - WR450F Engine Project (1/3)] 
* [https://drive.google.com/file/d/1U0y8geJOM3BxuCZlj71QGqXQ9cna6RCr/view?usp=sharing UWaterloo Formula Motorsports - WR450F Engine Project (3/3)]

[[Category: Internal Combustion]]

Engine

2022-08-28T16:11:15Z

TheoCamilleri: Added "See Also" section and 2 senior design project reports

The engine is the center of the internal combustion powertrain system. All other components of the greater system exist to service the engine in different ways. This means the engine is sensitive to design changes made across the entire powertrain. As of 2022, the FSAE rules require an internal combustion engine with a displacement of 710cc or less<ref>2022 fsae rules PDF: https://www.fsaeonline.com/cdsweb/gen/DownloadDocument.aspx?DocumentID=25e8885c-7397-4b2d-93b3-fc404960bab1</ref>. Available OEM motors within this displacement limit are largely sourced from motorcycles and snowmobiles. The purpose of an internal combustion engine is to convert the chemical energy in [[Fuel|gasoline]] or [[Fuel|ethanol]] into mechanical energy used to propel the car. The engine is one of the most complicated and often heaviest single parts of any vehicle.

''Please take a look at the outline in the discussion section before making changes to this page''

=Theoretical=
{{Main|Otto Cycle}}
=Structure=
Wikipedia does a very detailed explanation on general engine layout. This article will focus on motorcycle-style engines w.r.t. fsae competitions.

Engine configuration is a case where the 80/20 rule really applies: the last bit of effort really doesn't get you too much.
==Motorcycle Engines==
Motorcycle engines make up the vast majority of engines used in FS/FSAE. The structure and operation of motorcycle engines differs from typical car engines in a few key places: size, layout, redline bb. Engines used in these competitions are all under 150 lbs with 600cc 4 cylinders coming in at about 125-140hp, depending on brand or custom parts. Single cylinder engines typically weigh in the neighborhood of 70-90 pounds. These engines are almost exclusively overhead cam layout.
===Four Cylinder Engines===
These bike engines are supersport engines and already configured to power a motorcycle in the same weight range as most FS/FSAE cars at a high level (albeit with a bike transmission and unrestricted intake).
===Single Cylinder Engines===
crossflow cylinder discussion?
Yamaha yzf that have intake in front and exhaust in the rear - contrast to every other engine
==Snowmobile Engines==
==Other Engines==
=Engine Control=
{{Main|Engine control}}

Most modern engines are controlled by an engine control module (ECM) that determines when to inject the fuel and when to ignite the charge using various sensors and an engine tune.
=Goals=
The team's approach to the engine system is a balancing of multiple contradictory goals. With all else being held constant, running an engine at a higher power level will sacrifice some reliability and often efficiency. The balance struck is a critical design choice taken by the team.
==Reliability==
If the engine finishes endurance, it was reliable. (to some teams, to others, maybe they need one engine to last many years due to budget constraints or the fact that they're running an aprillia and there's only two in the US)

Michael Royce in Learn & Compete states that “[reliability] must be the number one technical objective of the team”.
===Engine Choice===
Engine to engine comparisons are difficult, and the literature is sparse at best. Most available engine specific reliability reports are anecdotal. However, brand comparisons are both easier and more widely available. Consumer Reports performed such a comprehensive study on motorcycle reliability<ref>https://www.consumerreports.org/cro/news/2015/04/who-makes-the-most-reliable-motorcycle/index.htm</ref>.

The reliability study is focused on how often the bikes would need to have repairs within the first four years of purchase. The three big Japanese motorcycle companies, Yamaha, Suzuki, and Honda, are the only three with under 15% of the bikes with repairs needed. Yamaha leads the brands with 11% compared to the 12% for Honda and Suzuki each. It is important to consider that this study included the bike as a whole, and that for all of the studied motorcycles “mechanical engine problems were relatively rare, with only 3 percent having trouble with the cylinder head or valvetrain, or with the crankcase, crankshaft, or pistons. Similarly, only 3 percent needed transmission repairs, although 7 percent had clutch problems.” LA Times <ref>https://www.latimes.com/business/autos/la-fi-hy-consumer-reports-motorcycle-ratings-20160127-story.html</ref> researching this study reported an interview stating "European bikes are engineered for character and sex appeal, and Japanese bikes are engineered for reliability,". This sentiment can be found echoed in the FSAE online forums.
===Servicing===
Another aspect of reliability is parts and tools availability. If something breaks, how easy is it to get hold of spare parts quickly in order to fix the engine? Do you need special tools to service the engine, and can you buy, borrow or manufacture these?
==Power & Torque==
All else being held equal, the car that produces more power will win the race. However, the primary function of the engine is to produce ''enough'' power to accomplish your designed team goals. Determining ''how much is enough'' is one of the fundamental questions to answer for the system. Additional questions are: At what RPM should we make peak power? Torque? To all of these questions, it depends heavily upon your team's design philosophy. All could be approximated from a rudimentary lap-time simulation, but will need to be confirmed via testing. There are a few ways to maximize engine power. These include, but are not limited to:
* Engine Choice
* Engine Modifications
* Spark and Fuel Tuning
* Auxiliary System Tuning (Intake, exhaust, etc)
I imagine there is a lot more to expand upon here - Novotny

Examples of teams design philosophy:
* we have a novice driver - we want our torque curve to be wide and flat
* we run a CVT and the engine will hold at a specific RPM during all events and we only want torque at that spot at the expense of all else
* we are a first year team and we dont know what we are doing so we are just going for peak torque everywhere
* we have the torque curve in the shape we want so we are just tuning for peak torque everywhere
* we are running with huge boost and need to run with an AFR of 9 or else we'll be building a bomb
* we can't get our engine to idle, so we're spending the whole year tuning at 1.5K RPM and didn't get around to anything else
* our driver is a 4th year masters student who has 8 years of FS driving and can put the engine wherever he wants, we are giving him peak torque at 9650 RPM because thats what gives him the fasted lap times during testing

Torque and power are determined by testing the engine on a dynomometer (need page for dynos).
==Power Limiting Factors==
====Restrictor====
[[Intake#Restrictor Power Limit Derivation|Restrictor power limit derivation]]
====Piston Speed Limit====
The competition limits the engine speeds allowed<ref>http://fsaeonline.com/content/Noise%20Test%20Speeds%202015.pdf</ref>.
a. Automotive / Motorcycle engines 914.4 m/min (3,000 ft/min)
b. Industrial Engines 731.5 m/min (2,400 ft/min)
The calculated speed will be rounded to the nearest 500 rpm.
==Efficiency==
high speed low drag babey
=Engine Modifications=

* To fill in, see note in editing for discussion points


=Simulation=
[[Otto Cycle|otto cycle]]

matlab sims for freshmen?

==1D engine sims==
Ricardo WAVE or GT-Power are commonly used. At the 1D level, simulations are good for understanding trends, but not necessarily getting a precise power number. These trends can help identify what changes to the system will have positive or negative impacts and to what extent they will change the output. Specific problems arise in the 1D models for the highly 3D behavior air achieves through the restrictor and plenum. The strength really lies in getting an engineering understanding of how to design an intake and exhaust for a given torque curve e.g. runner length, exhaust collector strategy (4-2-1 or a 4-1 exhaust), and plenum size.
==3D flame propogation sims in advanced research labs==
Just use a dynamometer or WAVE. 3D combustion CFD is really nasty and without experiments to support your model it is suspect.
=Oil System=
{{Main|Oil}}
=Mounting System=
Vibration Reduction
=Best Practices=
Engines can be incredibly robust to working conditions as long as they have air, compression, fuel, and spark. That being said, there are many places where a little love and care will reap huge benefits.

Many of the systems inside the engine operate on small tolerances. These tolerances mean it's wise to care for your engine, if you want it to last. Often, you can operate an engine outside of many of these tolerances, but you will lose performance and often risk severe damage to the components if not catastrophic failure.

When purchasing an engine, it is good practice to tear it down and inspect all parts for tolerance. If the engine is used, this is exponentially more important, as you will need to check for wear as well. Many teams (in the US) purchase used engines from motorcycle crashes, which can cause subtle damage to the internals, even if none is present on the outside of the engine.
==Servicing==
It will be well worth the investment to buy a service manual for the engine, or find a pdf online to print, and put together in a binder. If putting the pages in a binder, using plastic sleeves will protect the pages from oil damage. If using a book... be careful.

If the team is buying a used engine, perform a full engine teardown and service to ensure the engine is in full working condition.

'''Teardown'''
* Valvetrain
** Take the chance to measure your cams if you can for accurate simulations.
** Correct lashing
** Valve seating
* Head 
** check flatness, possibly deck
* Block
** Clean surface
** Check flatness, possibly deck
** Check cylinder roundness, if too far out of spec you'll lose a significant amount of power.
** Hone cylinders if changing rings, or if too shiny
* Pistons
** Clean faces
** check rod bearings for wear
** Check rings, likely good idea to replace if any blow-by on piston
* Crankcase
** Check for metal bits lol
* Get a new set of gaskets (MLS head gasket can likely be reused depending on condition)
* Get a new set of all TTY bolts

How/when to service.

How to diagnose issues.

Why combustion is more romantic than electric.

=Common Engines=
I think bc the cbr, r6, and a few of the 450s are so common, we can use this to list what we have done to optimize for FSAE use.

Example: gear removal, EWP, custom valving, suggested idles, mounting tips, weights/mass, stock water pump flow rates, oil recomendations, intake mounting recs. exhaust mounting recs, heat generation, wiring, injectors

Honda CBR 600RR
* remove first gear, breaks traction with any reasonable FDR
* max heat dissipation of ~10kW needed from cooling system (utoronto 2007<ref>https://manualzz.com/doc/35576578/design-and-optimzation-of-a-formula-sae-cooling</ref>)
* remove the thermostat control to keep temps down (this is something I am skeptical of. The thermal mass of the engine and cooling circuit is high enough that you won't get into trouble running the OEM thermostat if the cooling system operates correctly, and the engine is happier when it is at temperature. This is a relatively minor modification so running a lap with and without could be a decent test) 

Yamaha R6

Yamaha WR/YZ450
* WPI runs WiSECO high compression piston

see all engines [[List of Engines|here]]
=See Also=

* [https://drive.google.com/file/d/1Q5XaHZGjjahw5Ws1lvxdjKbLsm6vQtQK/view?usp=sharing UWaterloo Formula Motorsports - WR450F Engine Project (1/3)] 
* [https://drive.google.com/file/d/1U0y8geJOM3BxuCZlj71QGqXQ9cna6RCr/view?usp=sharing UWaterloo Formula Motorsports - WR450F Engine Project (3/3)]

[[Category: Internal Combustion]]