What is a HEMI ? . . .
Many who are unfamiliar with Chrysler's famed 426 HEMI engine are confused as to just exactly what is a HEMI.
A HEMI is an engine with a hemispherical (dome shaped) combustion chamber. The reasoning for this is that it enables the engine valves to be positioned to allow the fuel-air mixture to flow efficiently from the intake to the exhaust and produce maximum performance, especially at high RPM's. Chrysler introduced the concept in American cars in 1951 and it evolved to the now famous 426 HEMI engine in 1964.The 426 HEMI engine also had many other features for strength and performance.There is no other engine in the world more famous for performance than the 426 HEMI !!
Street HEMI Engine Specs
Engine Type: 90 deg OHV V8 (Hemispherical)
Engine Block: Cast Iron
Engine Heads: Cast Iron (Hemispherical)
Engine Mains: 4-Bolt (cross-bolted)
Crankshaft: Forged Steel
Conn Rods: Forged Steel
Pistons: Forged Aluminum (Hemispherical)
Bore x Stroke: 4.25" x 3.75"
Displacement: 426 cubic inches
Horsepower: 425 HP, 490 Ft-Lbs Torque
Comp Ratio: 10.25 to 1
CC Vol: 168cc min / 174cc max
Valve Dia: 2.25" Int, 1.94" Exh
Cam Type: Solid lifter (1966-1969)
Hydraulic lifter (1970-1971)
Cam Lift: .467" Int, .473" Exh (1966-1969)
.490" Int, .481" Exh (1970-1971)
Cam Duration: 276 deg (1966-1967)
284 deg (1968-1971)
Intake: Aluminum Dual-Plane, Dual-Carb
Carburation: 2 x 4-bbl Carter AFB
Ignition: Dual point, vacuum advance
Spark Plugs: N-10Y
Firing Order: 1-8-4-3-6-5-7-2
Exhaust: Cast Iron Headers, 2.5"outlet
