Editing V12 engine (section)

=== Balance and smoothness ===
Each bank of a V12 engine essentially functions as a [[straight-six engine]], which by itself has perfect primary and secondary [[engine balance]]. A four-stroke V12 engine has even firing order at V-angles of 60, 120, or 180 degrees<ref>. Engine Configuration and Smoothness Autozine Technical School https://www.autozine.org/technical_school/engine/Smoothness2.html
autozine.org
</ref>{{Unreliable source?|date=December 2024|sure=y|reason=personal website}} Many V12 engines use a V-angle of 60 degrees between the two banks of cylinders.<ref>{{cite book|last=Nunney |first=Malcolm James |title=Light and Heavy Vehicle Technology |edition=Fourth |publisher=Butterworth-Heinemann |year=2007 |pages=13–14 |isbn= 978-0-7506-8037-0}}</ref> V12 engines with other V-angles have been produced, sometimes using split [[crankpin]]s to reduce the unbalanced vibrations. The drawbacks of V12 engines include extra cost, complexity, friction losses, and external size and weight, compared with engines containing fewer cylinders.

At any given time, three of the cylinders in a V12 engine are in their power stroke, which increases the smoothness of the power delivery by eliminating gaps between power pulses.

A V12 engine with a 180 degree V-angle is often called a [[flat-twelve engine]]. These are also sometimes called '[[Flat engine#Boxer engine|boxer]] twelve' engines, however this terminology is incorrect for the majority of 180-degree V12 engines, since they use shared crankpins and are therefore not configured as true boxer engines.<ref>{{cite news |url=https://airandspace.si.edu/collection-objects/rolls-royce-condor-ia-v-12-engine |title=Rolls-Royce Condor IA, V-12 Engine |date=2016-03-10 |work=National Air and Space Museum |access-date=2017-05-24 |language=en |archive-date=2017-08-24 |archive-url=https://web.archive.org/web/20170824095342/https://airandspace.si.edu/collection-objects/rolls-royce-condor-ia-v-12-engine |url-status=dead }}</ref>

Theoretically, the rotating parts of a V12 racing engine could be lighter than a crossplane V8 engine of similar displacement due to the V12 engine not requiring counterweights on the crankshaft or as much inertial mass for the flywheel. In addition, the exhaust system of a V12 engine is much simpler than would be required for a crossplane V8 engine to achieve pulsed exhaust gas tuning. However, the use of V12 engines in motor racing is uncommon in the 21st century.