As a follow up to the Tale of Two Sixes (January 23), inline six-cylinder engines have become popular again, with luxury and upmarket brands like BMW and Mercedes leading the way.  Ford also recently had a successful turbo six cylinder for the Australian market.

AMC 4 liter straight six

Many Chrysler and Jeep fans have a special place in their hearts for inline six cylinder engines like the venerable Slant Six and the five million AMC 4.0 six cylinders, which were both legends of their time.  The Chrysler Slant Six began production in 1959, and the AMC six cylinder began production in 1964.  Each engine lasted over forty years in production.

If there really is another inline six coming from FCA — and internal communications referring to a GME T6 suggest there is — what does Allpar expect to see?

Let’s start with the block. Allpar thinks it will have be either sand or die cast aluminum, with hardened cylinder walls rather than Chrysler’s traditional liners.  Further, we expect efficiency measures such as a liquid-cooled EGR system and liquid cooling of the turbocharger.

Speaking of turbocharging, Allpar has a feeling this engine is not getting a single small turbo.  We think this engine will be taking in some serious air, using a twin scroll or variable-vane large turbocharger to fine-tune the airflow and allow for quick spooling.  To counter turbo lag and increase efficiency, the engine may use a mild-hybrid system, similar to the eTorque system used on the Ram 1500 and Jeep Wrangler.

slant six

Allpar expects an aluminum cylinder head similar to the one used on the “Hurricane” turbo-four used in the 2019 Jeep Wrangler and Cherokee.  We expect the typical 500cc-per-cylinder formula to be used, which would provide a 2.9999-liter version that has tax/regulation advantages in some countries.

We also think there could be a high output version for use in specific Dodges — 385-410 horsepower along with 420-440 pound-feet of torque is a good yard-dart target to aim for.

We believe the future is looking bright at FCA in the engine development department. Still, while this engine may eventually replace the base V8 in some vehicles, there are still some tricks up the sleeve for the Hemi.  Don’t be mistaken — the V8 at Dodge and Ram is far from dead.

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