MrMopar64 wrote:
No, the new engine is a totally new design from the block up that can handle the higher pressures that accompany increased power density. Different injection system all around, pre-supply pump in-tank, turbo, intake system, etc. etc.
The only application that uses the 545RFE is the JK and even still it takes full torque of the engine (look in the advertising, it's greater than the engine in the KJ). The KA/KK use the W5A580 transmission which is a dream.
The increased power density is about 35 ft-lbs of torque apparently. In early 2005, VM Motori had the factory specifications on the R428 (original 2.8L) on their web site. The specifications were the original power levels before Chrysler detuned it for the US release of the 05-06 KJ's and the ratings were ~175hp (177cv)(130KW) and ~302 (410Nm) ft-lbs of torque. This was long before the F37 fiasco. That pdf document disapeared shortly after the release of the RA428 engine and is no longer available online. So we know the original R428, pre US release, was factory rated at higher power levels than it is now. The difference was most likely in the ECM tuning.
The increased density of the RA428 appears to be the same hp and about 35 ft-lbs of torque over the original factory specifications of the R428.
Question for MrMopar64 - Does the new RA428 still have wet liners and a tunnel crankshaft?