Editing Ford flathead V8 engine (section)

==Components==
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{{Original research section|date=February 2019}}
{{Cleanup section|reason=<br />This section should contain information on engine design and functionality – currently, it is focussed too much on modicifications for hot-rodding purposes, without citing proper sources.|date=February 2019}}
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===Crankshaft===
The crankshaft development for the Ford flathead V8 was pioneering. The engine's production development program began with a [[forging|forged steel]] crank, per conventional practice, but Ford then developed the improved [[foundry]] practice, [[heat treatment|heat-treating]], and materials handling logistics to make the cranks from [[steel casting|cast steel]] instead, yielding a crank just as strong, but less expensive to produce.<ref name="Sorensen1956pp230-231">{{Harvnb|Sorensen|1956|pp=230–231}}.</ref> These new methods were patented.<ref name="Sorensen1956pp230-231"/> The simple three-main-bearing crankshaft attached two connecting rods to a single crankpin, one rod from each cylinder bank. As with other crankshafts, [[balancing machine|static and dynamic balancing]] was performed ([https://www.youtube.com/watch?v=3RB3z1er9Sw&t=14m53s as this video on the Ford flathead V8 shows]).

The short crankshaft proved quite durable in comparison to six-cylinder engines when roughly handled. For these reasons, the flathead Ford became a favorite among hot-rodders, and this in turn led to a rich supply of aftermarket performance parts. With the use of specialized pistons or connecting rods the stroke of the crankshaft could be increased by welding and regrinding as a method of increasing engine displacement, usually in combination with overboring.

===Block===
[[File:The Valve In Block Design or Flathead Block.jpg|thumb|Engine block of a flathead V8 showing the location of the valve ports (the holes above the large cylinder bores)]]

One of the most important innovations in the Ford flathead V8 was the [[sand casting|casting]] of the [[crankcase]] and all 8 [[cylinder (engine)|cylinders]] in one [[cylinder block|engine block]]. This level of [[monobloc engine|monobloc design]] for V-8 blocks had been accomplished before,<ref name="Automobile_Trade_Journal_1916_p101A-103">{{Citation |author=Editorial staff |year=1916 |title=Pennsylvania S.A.E. section formally organized and holds first professional session |journal=Automobile Trade Journal |volume=20 |pages=101A–103 |url=https://books.google.com/books?id=zqgyAQAAMAAJ&pg=RA2-PA102 |postscript=.}}</ref> but it had never seen mass production. Making it practical for the latter was an example of the production development needed to bring a V8 engine to the widely affordable segment of the market.<ref name="Sorensen1956p225"/> Most V engines of the time had multiple cylinder blocks bolted to a common crankcase (itself a separate casting). At most, each bank of the V was an integral block, but many V engines had four- or even six-cylinder blocks, with cylinders cast in pairs or triples. Like most other engine blocks of the 20th century, it was [[cast iron]]; but the foundry practice (e.g., workflows, materials handling) was a revolutionary advancement in the mass production of castings.<ref name="Sorensen1956pp107,227-231">{{Harvnb|Sorensen|1956|pp=107,227–231}}.</ref> [[Charles E. Sorensen]] lived up to his longtime nickname at Ford, "Cast-Iron Charlie", by leading this revolution to bring Ford's first V8 to market.<ref name="Sorensen1956pp107,227-231" />

As with any V8, the block was relatively light for the displacement supported. The cooling jacket reaches down to the bottom dead center, which is unusually low. American engineers at the time believed this would improve the piston cooling.<ref name="K215">{{Harvnb|Kremser|1942}}. p 215</ref> The bottom of the block formed the parting line for the main bearing caps. The most complex part of the block was the exhaust passage routing. The exhaust valves were on the inside of the '''V''' and exhaust flow was initially downward and passed around the cylinders through the water jacket to exit on the outside of the cylinder block. The routing of the exhaust through the water jacket put an extremely heavy load on the cooling system and led to frequent overheating, especially on early models, if the cooling system was not maintained. Somewhat primitive water pumps used until the advent of the 1948 8RT and 1949 8BA models also contributed to the overheating problem. The space for the exhaust flow was also somewhat restricted, so the exhaust passages were tall and narrow in some locations. The gas flow past the rough sand castings could be greatly improved by polishing the passages. In early blocks, some cylinder walls were extremely thin due to cores shifting during casting.

===Bearings===
The engines built from 1932 to 1935 had [[Babbitt bearing|poured main bearings]] which required skill and machine shop equipment to overhaul. Part of the 1936 production and all production from 1937 to the end of flathead V8 production had both replaceable shell main bearings and connecting rod inserts, enabling straightforward and low cost rebuilding, another reason why the Ford was a favorite of amateur mechanics. These shell main bearings are made of a cadmium silver alloy.<ref name="K215" />

=== Camshaft and timing ===
The Ford flathead V8 has a single camshaft located inside the engine block above the crankshaft. It is spur gear driven; the camshaft's spur gear is made of plastic. The camshaft has three camshaft bearings. A lid made of cast iron covers the camshaft spur gears; the ignition distributor is placed on top of this lid and is driven by the camshaft spur gears. For powering the fuel pump, the camshaft is fitted with an extra cam located in the bearing on the flywheel side.<ref name="K215" />

===Lubrication===
Ford products used high [[oil pressure]] for lubrication for the main and rod bearings, as do all modern vehicle combustion engines. This offered a significant performance advantage, as full pressure lubrication allowed for continuous use above 3500&nbsp;rpm and would not starve the rod bearings for oil, which was necessary for high performance applications, such as racing. For this reason, bank robber [[Clyde Barrow]] preferred to steal Fords as getaway vehicles.<ref>{{Cite web |title=Letter from Clyde Barrow to Henry Ford Praising the Ford V-8 Car, 1934 |date=10 April 1934 |website=[[The Henry Ford]] |url=https://www.thehenryford.org/collections-and-research/digital-collections/artifact/281082/}}</ref> It also eliminated a complex oil jet system to feed the rod bearings in the oil pan. As a side benefit to a prospective purchaser of a used vehicle, this also enabled the condition of the connecting rod and main bearings to be determined indirectly by observation of the oil pressure gauge after the vehicle was warmed up, provided that oil of normal viscosity was in use.

===Exhaust===
The exhaust outlets in the 1932&ndash;48 cars and the 1932&ndash;47 trucks were near the front of the manifolds aiming down and sometimes out. A Y-pipe took the exhaust gases to the right side of the vehicle to a single muffler, then to a single pipe out the back on the right side. The left side exhaust manifold exhausted to the front in the 1949–53 Ford cars, where a crossover pipe took the exhaust to the forward end of the right side manifold on the car engines and between the 1st and second cylinder on some trucks, in turn exhausting to a single pipe at the rear.

A common conversion for the 1949&ndash;53 Ford cars and 1952&ndash;53 Mercurys was to block off the right forward manifold entrance and route the left side exhaust to a new pipe to form a dual exhaust system with better flow characteristics. These typically involved installation of free-flowing mufflers, which if at a legal noise level still allowed low frequency sounds to pass, giving a characteristic rumbling dual exhaust sound to these systems. In the 1950s shortcut exhaust outlets with manually removed covers were added to street machines in emulation of vehicles intended for high speed straight line racing on dry lake beds, typically located just behind the front wheel, although chromed external runners sometimes extended to just forward of the rear wheel. These covers were referred to as ''lake plugs'', the pipes as ''lake pipes''. This style exhaust was also used legally in sanctioned drag racing and illegally in unsanctioned performance demonstrations.

===Internal Air flow===
More extreme modifications were to improve the airflow by removing material from the top of the block between the valves and the cylinders (called ''relieving''), increasing the size of the inlet and exhaust passages (called ''porting''), and by ''polishing'' the sand-cast surfaces to improve air flow. Increased compression ratios could be cheaply obtained by milling material from the head or by obtaining aluminum heads as aftermarket parts. Higher capacity intake manifolds were similarly available. Changing the camshaft to a higher performance version required head removal so that the valves could be held up out of the way, so this was usually done only as part of a substantial rework of the basic engine.

===Overhead-valve kits===
A popular modification for the flathead was conversion to an [[overhead-valve]] configuration, and many such modification kits were available, including the ''Ardun'' heads<ref>[http://www.ardun.com Announcing the Reintroduction of the ARDUN OHV Cylinder Head]. ''ardun.com'', 1 July 2008</ref><ref>{{Cite news |at=The Grand Finale |title=Automotive History: The Small Ford Flathead V8 (V8-60), Part Three – The Simca Years |date=5 October 2016 |website=Curbside Classic |url=http://www.curbsideclassic.com/curbside-classics-european/automotive-history-the-small-ford-flathead-v8-v8-60-part-three-the-simca-years/}}</ref> from [[Zora Arkus-Duntov]] who was to go on to fame as the "father of the Corvette". These conversions were not initially demanded by [[hot rod]]ders looking for extra power, as they had not yet exhausted the capabilities of the flathead configuration, but were demanded by users of the engine in trucks and other such high load applications, where the constant flow of hot exhaust through the block to the exhaust manifolds caused the entire engine to overheat; the overhead-valve heads routed the exhaust out more directly, and away from the block.