Editing Overhead camshaft engine (section)

=== Timing belt / timing chain ===
{{Main|Timing belt (camshaft)}}
[[File:Replacing a timing belt.jpg|thumb|upright=0.8 |Rubber timing belt during installation]]
The rotation of a camshaft is driven by a [[crankshaft]]. Many 21st century engines use a toothed ''timing belt'' made from rubber and kevlar to drive the camshaft.<ref name=Hillier/><ref name=dansmc.com>{{cite web|url=http://www.dansmc.com/camchain.htm|title=Dan's motorcycle 'Cam Drives'|website=www.dansmc.com|access-date=29 August 2012}}</ref> Timing belts are inexpensive, produce minimal noise and have no need for lubrication.<ref name="Decker">{{Cite journal|last= Decker|first= John|title= Saturday Mechanic: Replacing Your Timing Belt|journal=[[Popular Mechanics]]|date= June 1993|volume=  170|issue=  6|issn= 0032-4558|url= {{Google books|JOQDAAAAMBAJ|Popular Mechanics Jun 1993|page=93|plainurl=yes}}|access-date=1 March 2015|editor-last= Oldham|editor-first= Joe|publisher= Hearst|location= New York, NY US}}</ref>{{refpage|page=93}} A disadvantage of timing belts is the need for regular replacement of the belt;<ref name="Decker"/>{{refpage|page=94}} recommended belt life typically varies between approximately {{convert|50000|-|100000|km|mi|abbr=on}}.<ref name="Decker"/>{{refpage|pages=94-95}}<ref name="Dorries">{{Cite book|last= Dorries|first= Elisabeth H.|title= TechOne: Automotive Engine Repair |url= {{Google books|KsYFA0skuZ8C|TechOne: Automotive Engine Repair|page=250|plainurl=yes}}|access-date= 1 March 2015|publisher= Thompson Delmar Learning|location= Clifton Park, NY US|year= 2005|isbn= 1-4018-5941-0|lccn= 2004057974}}</ref>{{refpage|page=250}} If the timing belt is not replaced in time and fails and the engine is an [[interference engine]], major engine damage is possible.

The first known automotive application of timing belts to drive overhead camshafts was the 1953 [[Bill_Devin#Devin_Enterprises|Devin-Panhard]] racing specials built for the SCCA H-modified racing series in the United States.<ref name="Pace&Brinker">{{cite book|last1= Pace|first1= Harold W.|last2= Brinker|first2= Mark R.|title= Vintage American Road Racing Cars 1950-1969|year= 2004|page= 62|publisher= MotorBooks International|location= St. Paul MN US|isbn= 0-7603-1783-6|url={{Google books|oZempfWXoe4C|Vintage American Road Racing Cars 1950-1969 |plainurl=yes}}|access-date= 27 February 2015}}</ref>{{refpage|page=62}} These engines were based on Panhard OHV flat-twin engines, which were converted to SOHC engines using components from Norton motorcycle engines.<ref name="Pace&Brinker"/>{{refpage|page=62}} The first production car to use a timing belt was the 1962 [[Glas 1004]] compact coupe.<ref>{{cite book |last=Norbye |first=Jan P. |title=BMW - Bavaria's Driving Machines |year=1984 |publisher=Publications International |location=Skokie, IL |isbn=0-517-42464-9 |chapter=Expanding on Excellence: The 5-Series and 3-Series |page=[https://archive.org/details/bmwbavariasdrivi00norb/page/191 191] |chapter-url-access=registration |chapter-url=https://archive.org/details/bmwbavariasdrivi00norb/page/191 }}</ref>

Another camshaft drive method commonly used on modern engines is a ''timing chain'', constructed from one or two rows of metal [[roller chains]].<ref name=Hillier/><ref name=dansmc.com/> By the early 1960s most production automobile overhead camshaft designs used chains to drive the camshaft(s).<ref name="Boddy">{{cite journal|last=Boddy |first=William |author-link= Bill Boddy |url=https://www.motorsportmagazine.com/archive/article/january-1964/17/random-thoughts-about-ohc|title= Random Thoughts About O.H.C. |journal= [[Motor Sport (magazine)|Motor Sport]]|date= January 1964 |volume= XL|issue= 1|publisher= Teesdale Publishing|location= London, UK}}</ref>{{refpage|page=17}} Timing chains do not usually require replacement at regular intervals, however the disadvantage is that they are noisier than timing belts.<ref name="Dorries"/>{{refpage|page=253}}