5.7 vs. 6.1

[Tac119]

So the new 6.1L Hemi has a larger bore, stroke or, is a completely different engine? It's only .4 difference yet boasts to have an 85hp increase. Does anyone know for sure the differences? I may be trading my RT in. It kinda pisses me off.

[BrilliantBlackHemi]

The list of improvements of the 6.1 over the 5.7 is a mile long and there's no surprise they got 85 more horse easily. Somewhere there is a great writeup on the details, and after reading it, I was a little pissed off too, and I knew it was coming a year later and still bought a 5.7L. I guess I didn't expect it to be THAT much better, but it appears it maybe.

Anyone have a link to that writeup? I'll have to search for it. I think I saw it on 300Cforums.com.

[BMWDON]

Increased compression, increased displacement, improved breathing (intake manifold improvement, bigger valves(I think they are sodium filled as well), higher flowing exhaust manifold back exhaust)...and I'm sure a more aggressive computer programming..all this stuff adds up to an additional 85 HP and 35 ft/lbs torque. It isn't anything innovative to get this extra power :|

[SRT84me]

I found this......


Just as the very first Charger - the original 1964 "Charger by Dodge" concept car -- sported a HEMI V-8, the all-new 2006 Dodge Charger SRT8 gets its motivation from a HEMI, too. In this case, it's a big-bore, SRT-engineered version producing 425 horsepower and 420 lb.-ft. of torque.

Several features of the new 6.1-liter SRT HEMI recall the legendary HEMI engines of previous decades, including the namesake hemispherical combustion chambers that provide power and efficiency, orange-painted cylinder block, black valve covers, and even the horsepower rating (with less displacement, the 6.1-liter HEMI's 69.8 horsepower-per-liter rating exceeds that of the legendary Street HEMI of the 1960s and '70s).

To create the 6.1-liter version of the Chrysler Group's HEMI, SRT powertrain engineers applied tried-and-true engine-building tricks honed by generations of American hot-rodders.

They unleashed 85 more horsepower by adding more cubic inches, increasing the compression ratio, redesigning the cylinder head, intake and exhaust systems for increased flow, and increasing engine speed.

For more displacement, SRT engineers bored out the diameter of the cylinders in the HEMI by 3.5 millimeters each in order to increase the total displacement to 6.1 liters from 5.7 liters.

Compression ratio was also increased to 10.3:1 from 9.6:1, increasing engine efficiency and power.

Engine breathing was increased with new higher-flow cylinder heads, a specially designed intake manifold, and exhaust headers with individual tubes encased in a stainless steel shell, all unique to the 6.1-liter HEMI engine. Larger-diameter valves and reshaped ports in the heads allow for maximized air flow. The intake manifold was designed with larger-diameter and shorter runners for higher-speed tuning. Exhaust is routed through a large-diameter (2.75-inch vs. 2.5-inch) exhaust system with 3.5-inch chrome tips.

To further increase horsepower, performance-oriented camshaft profiles were developed to allow more air in and out of the cylinders, as well as manage a higher engine speed. SRT engineers increased HEMI's peak power output engine speed nearly 20 percent to 6,000 revolutions per minute (rpm) from 5,000 rpm. Intake and exhaust valve stems are hollow, and exhaust valve stems are filled with sodium to help dissipate heat more efficiently.

The high-performance SRT 6.1-liter HEMI is strengthened with redesigned components, including a reinforced engine block, forged steel crankshaft, high-strength powdered-metal connecting rods, floating-pin pistons (cooled by oil squirters), and an oil pan modified to manage oil return to the pan sump at high engine speeds.

Power for the SRT 6.1-liter HEMI is channeled through an A580 five-speed automatic transmission with specially calibrated driver-selectable AutoStick®, which offers fully automatic or manual shifting selection. A heavy-duty four-flange prop shaft sends the torque from the transmission to an upgraded differential and axles.

[Rev.Hammer]

The thing is that by my estimates using some software that I have; 500-520 hp are possible N/A. Supercharged with intercooler can get into seriously obscene levels. This baby was MADE for power!

[BMWDON]

So long as the block walls and bottom end are able to handle it!

The thing is that by my estimates using some software that I have; 500-520 hp are possible N/A. Supercharged with intercooler can get into seriously obscene levels. This baby was MADE for power!

[FStephenMasek]

Tac119 - as the posts above show, the 6.1 liter engine really is different in many important ways. However, the engine is not the only significantly different part of the SRT models - the brakes are much better, the body is designed to manage airflow at higher speeds, the suspension is stiffer, the seats are designed to provide more lateral support, and so forth. Maybe Hammerfoot would want your used RT if you decide to sell?

[Brian_R170]

Increased compression, increased displacement, improved breathing (intake manifold improvement, bigger valves(I think they are sodium filled as well), higher flowing exhaust manifold back exhaust)...and I'm sure a more aggressive computer programming..all this stuff adds up to an additional 85 HP and 35 ft/lbs torque. It isn't anything innovative to get this extra power :|

425hp is nothing to sneeze at, but it sure seems like DCX is sandbagging the 6.1L's potential. New cams, bigger valves, better breathing intake manifold & headers, higher compression, revised engine computer, and a 20% increase in max RPM and all they get is 25% boost in power and 10% boost in torque? Plus there are alot of strengthened components (crank, block, rods, & pistons). I wouldn't be suprised to see a 450+ hp version show up in 2 or 3 years.