Editing Engine block (section)

== Monoblocs ==
[[File:De Dion-Bouton engine (Rankin Kennedy, Modern Engines, Vol III).jpg|thumb|right|upright=1.0 |[[De Dion-Bouton]] engine, circa 1905. The cylinder heads are integrated into the engine block, but the crankcase is separate.<ref name="Rankin Kennedy, Modern Engines, Vol III, De Dion-Bouton" >{{cite book |series=The Book of Modern Engines and Power Generators |title=The De Dion-Bouton Engine and Cars |year=1912 |last=Kennedy |first=Rankin |publisher=Caxton |location=London |pages=78–89 |ref=Rankin Kennedy, Modern Engines, Vol III}}</ref> ]]

[[File:Cylinder block and head of sidevalve engine (Autocar Handbook, Ninth edition).jpg|thumb|Typical 1930-1960 [[flathead engine]] with integrated crankcase. The cylinder head is tipped upwards for illustrative purposes.]]
An engine where all the cylinders share a common block is called a [[monobloc engine]]. Most modern engines use a monobloc design, and few have a separate block for each cylinder. This has led to the term "engine block," which usually implies a monobloc design, with "monobloc" rarely used.

In the early years of the internal combustion engine, [[casting]] technology couldn't produce large castings with complex [[core (manufacturing)|internal cores]] (for [[water jacket]]s etc). Most early engines, particularly those with more than four cylinders, had their cylinders cast as pairs or triplets of cylinders, then bolted to a separate crankcase.

As casting techniques improved, an entire cylinder block of 4, 6, or 8 cylinders could be produced in one piece. This monobloc construction was more straightforward and more cost-effective to produce. All the cylinders and crankcase could be made in a single component for [[straight engine]] cylinder layouts. One of the early engines produced using this method is the 4-cylinder engine in the [[Ford Model T]], introduced in 1908. The technique spread to [[straight-six engine]]s and was commonly used by the mid-1920s.

Up until the 1930s, most [[V engine]]s retained a separate block casting for each cylinder bank, with both bolted onto a common crankcase (itself a separate casting). For economy, some engines were designed to use identical castings for each bank, left and right.<ref name="Ludvigsen">{{cite book |title=The V12 Engine |last=Ludvigsen |first=Karl |author-link=Karl Ludvigsen |publisher=Haynes Publishing |year=2005 |isbn=1-84425-004-0}}</ref>{{refpage|page=120}} A rare exception was the [[Lancia]] 22½° narrow-angle [[V12 engine|V12]] of 1919, which used a single block casting combining both banks.<ref name="Ludvigsen"/>{{refpage|pages=50-53}} The [[Ford flathead V8 engine|Ford flathead V8]]{{snd}}introduced in 1932{{snd}}represented a significant development in the production of affordable V engines. It was the first V8 engine with a single-engine block casting, putting a V8 into an affordable car for the first time.<ref name="Sorensen1956pp225-231">{{cite book |last1=Sorensen |first1=Charles E. |last2=Williamson |first2=Samuel T. |title=My Forty Years with Ford |date=1956 |publisher=Norton |location=New York |isbn=9780814332795 |pages=225–231}}</ref>

The communal water jacket of monobloc designs permitted closer spacing between cylinders. The monobloc design approach also improved engines' [[Stiffness|torsional rigidity]] as cylinder numbers, engine lengths, and power ratings increased.

=== Integrated cylinder block and crankcase ===
Most engine blocks today, except some unusual V or radial engines and large marine engines, use a monobloc design with one block for all cylinders plus an integrated crankcase. In such cases, the skirts of the cylinder banks form a crankcase area of sorts, which is still often called a crankcase despite no longer being a discrete part.

Using steel cylinder liners and [[Main bearing|bearing]] shells minimizes the effect of the relative softness of aluminium. Some engine designs use [[plasma transferred wire arc thermal spraying]], instead of cylinder sleeves, to further reduce weight. These types of engines can also be made of [[compacted graphite iron]], such as in some diesel engines.<ref>{{cite news |url= http://foundrymag.com/materials/navistar-now-producing-engine-blocks-heads-cgi |title=Navistar Now Producing Engine Blocks, Heads in CGI |work=Foundry Management & Technology |first=Robert |last=Brooks |date=January 25, 2012 |access-date=May 2, 2017}}</ref>

=== Integrated cylinder block and head ===
{{multiple image
| title             = Integrated cylinder head engines
| width             = 220
| align             = right
| direction         = vertical
| image1            = Daimler DB 605 cutaway.jpg
| caption1          = [[DB 605]] V12 aircraft engine
| image2            = Honda GX 160 engine.jpg
| caption2          = Honda GX 160 engine in a ride-on lawnmower
}}

Some modern consumer-grade [[small engine]]s use a monobloc design where the cylinder head, block, and half of the crankcase share the same casting. Apart from cost, one reason for this is to produce an overall lower engine height.{{Citation needed|date=November 2022}} The primary disadvantage can be that repairs become more time-consuming and impractical.

An example of engines with integrated cylinder heads are the Honda [[list of Honda engines#Power equipment|GC]]-series and GXV-series engines, which are sometimes called "Uniblock" by Honda.<ref>{{cite web |title=Honda General Purpose Engines: GC Series - Single Cylinder |url= http://www.perr.com/honda.html |url-status=dead |archive-url= https://web.archive.org/web/20101127185645/http://perr.com/honda.html |archive-date=2010-11-27}} Includes sectioned drawings</ref>

=== Integrated crankcase and transmission ===
Several cars with [[transverse engine]]s have used an engine block consisting of an integrated [[transmission (mechanics)|transmission]] and crankcase. Cars that have used this arrangement include the 1966-1973 [[Lamborghini Miura]]<ref name="netcarshow.com">{{cite web |title=Lamborghini Miura SV (1971) |url= https://www.netcarshow.com/lamborghini/1971-miura_sv/ |website=www.netcarshow.com |access-date=12 December 2018 |language=en}}</ref> and cars using the BMC [[BMC A-series engine|A-series]] and [[BMC E-series engine|E-series]] engines.<ref name="aronline.co.uk">{{cite web |title=H and K-Series prototypes: BL's first attempt at replacing the A-Series |url= https://www.aronline.co.uk/facts-and-figures/engines/engines-h-and-k-series-prototypes/ |website=www.aronline.co.uk |access-date=12 December 2018 |date=22 July 2017}}</ref><ref name="ateupwithmotor.com">{{cite web |title=Tiny and Triumphant: The Morris / Austin Mini |url= https://ateupwithmotor.com/model-histories/original-mini-history/ |website=www.ateupwithmotor.com |access-date=12 December 2018 |date=1 May 2010}}</ref> This design often results in the engine and transmission sharing the same oil.

Motorcycles such as the [[Honda CB750]] use a similar layout, with the cylinder block and crankcase integrated with part of the transmission.

Many farm [[tractor]] designs integrate the cylinder block, crankcase, transmission, and rear axle into a single unit. An early example is the [[Fordson]] tractor.