The cast-aluminum pistons feature a thin 1.5/1.5/3mm ring package hooked to a 6.24-inch long powdered metal connecting rod. The pistons feature a slight 9cc dome. Also note how tight the ring pack is to the top of the piston and the friction-reducing piston skirt coating.
The intake is constructed of a Nylon 6 composite material that is not only lightweight but also integrates several other components that the engineers call an Integrated Air Fuel Module. We've decided to still call it an intake manifold, thank you. One of the design goals was that intake port flow loss would be 10 percent or less when the intake is bolted to the head, which they achieved. Like many other Hemi engine components, there is no separate intake gasket. The intake incorporates an elastic seal that is held in place and does not need to be replaced. This makes swapping intakes a breeze.
Perhaps the biggest question is how this new Hemi will respond to swapping into earlier cars. Certainly the electronic throttle and the MDS system will present challenges, but in our sidebar, you'll see that at least one enterprising car crafter has overcome the obstacles. As with any new engine, there aren't a ton of parts for the new Hemi as yet, but that's just a matter of time.
The hydraulic roller cam is located very high in the block, which reduces pushrod length. Note the large-diameter cam journals, which reduce deflection.
Hemi Specs
(all specs in inches unless specified)
•Engine: DaimlerChrysler Hemi V-8, pushrod, 16 valves
•HP & torque: 345 hp at 5,400, 375 lb-ft at 4,200 (truck); 340 hp at 5,200, 390 lb-ft at 4,000 (car)
•Displacement: 5.7 L (346 ci)
•Firing order: 1-8-4-3-6-5-7-2
•Bore x stroke: 3.92x3.58
•Compression: 9.6:1
•Block: Cast iron, deep-skirt design
•Deck height: 9.25
•Crankshaft: Nodular iron, five main bearings
•Main journal diameter: 2.55
•Rod journal diameter: 2.12
•Connecting rod: Powdered metal, 6.24 inches, 597 grams
•Rod length/stroke: 1.74:1
•Piston: Cast aluminum, 413 grams, coated skirt
•Rings: 1.5/1.5/3mm ring package
•Cylinder head: Aluminum, semi-hemispherical chamber
•Intake valve angle: 18 degrees
•Chamber volume: 85 cc
•Intake valve: 2.00
•Exhaust valve: 1.55
&•bull;Spark plugs per cyl.: Two
•Intake valve lift: 0.472
•Exhaust valve lift: 0.460
•Rocker arm ratio: 1.65:1
•Valvesprings: Conical, 97 pounds closed, 242 pounds @ max lift
•Intake manifold: Nylon 6 material
•EFI: Sequential w/closed loop control
•Throttle-body: 80 mm, electronic
•Exhaust manifold: Cast iron