CNG HEMI Available?

Discussion of the 5.7L-6.1L-6.4L HEMIs.

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CNG HEMI Available?

Post by scottm » Fri Sep 23, 2011 9:40 pm

CNG Hemi available? ... -available
Jordie pointed out that Dodge’s “body builder” documentation now includes a CNG (compressed natural gas) Hemi, available on Ram 2500 pickups. While none of Detroit’s Big Three are new to CNG, having made it available to fleets numerous times in the past, this may be a first for the Hemi.

The engine, coded EZF, is available only with the 66RFE automatic transmission, long bed, crew cab, and 3:373 axle ratio, in ST and SLT trim; the GVWR is 8,800 lb, the same as with the standard Hemi, but the payload is reduced due to a higher base weight (the system appears to add around 780 pounds, most likely due to the tank weight).
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Re: CNG HEMI Available?

Post by mart » Sat Sep 24, 2011 8:22 pm

Interesting! I wonder, since this package is not widely known or advertised and considering the very specific specs and specific mandatory options, if this CNG package was (or is being) built on special order for a single specific fleet customer - sort of like GM offered it's 'COPO' packages for fleet buyers back in the '60's and 70's?? Also, I wonder what the horsepower and torque ratings are for this CNG Hemi? Due to CNG having less BTUs per pound than gasoline, gasoline engines converted to run on CNG generally have a lower output, unless the compression is raised (CNG can easily and safely tolerate compression ratios in the 13 to 14 to 1 range!) - and the cam and ignition timing is altered to take advantage of the vastly increased octane rating and much slower and cooler burning of CNG. Also, the exhaust can be freed up, because CNG burns cleanly enough, that a catalytic converter is not required. If the engine has actually been optimized to run on CNG, rather than just minimally converted to use it, a late model Hemi on CNG could be a real killer!


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