16-05-2010, 08:27 AM
A Chrysler Hemi engine, known by the trademark Hemi, is a series of V8 internal combustion engines built by Chrysler that utilize a hemispherical combustion chamber. A Chrysler Hemi engine, known by the trademark Hemi, is a series of V8 internal combustion engines built by Chrysler that utilize a hemispherical combustion chamber. three generations of hemi engines were built by chrysler for automobiles.
-Chrysler FirePower engine from 1951“1958
-The second one 1964“1971
-the third beginning in 2003
the valves of a two valve-per-cylinder engine to be angled rather than side-by-side due to the hemispherical combustion chamber. more space in the combustion chamber roof is thus created for the use of larger valves and also straightens the airflow passages through the cylinder head.the engine's airflow ("breathing") capacity is significantly improved thus improving the high power output from a given piston displacement. With a hemi combustion chamber, there is minimal quench and swirl to burn the fuel-air mix thoroughly and quickly.
FirePower with the OHV V8:
Using their military experience with the hemispherical combustion chambers, Chrysler decided to use this layout in their first OHV V8.
FirePower and FireDome were the nicknames of the different engine types here.
Hemi design reintroduced:
Hemi engines were produced only in less numbers for consumer sale due to their relatively high cost and poor street-use reputation[citation needed], the engine became legendary, with "Hemi" becoming one of the most familiar automobile-related words in the United States. In NHRA top fuel racing, the Hemi was usually equipped with a large Roots type supercharger.
Modern Hemi:
they are flatter and more complex shape than a truly hemi combustion chamber. . It uses a coil-on-plug distributorless ignition system and two spark plugs per cylinder to shorten flame travel . the 5.7 version is rated at approximately one horsepower per cubic inch. Multi-Displacement System (MDS) is used in some versions which can shut off two cylinders on each bank under light load to improve fuel economy.
for more details, visit this link:
http://en.wikipediawiki/Chrysler_Hemi_engine
http://hemi