Jasper Engines & Transmissions offers a late-model remanufactured GM V8 engine with a DFM-Delete option. This option is available for 5.3L and 6.2L engines. Please click the above image to watch a video on JASPER’s remanufactured GM V8 with the DFM-Delete option.
So, what’s the difference between the DFM and the first-generation AFM engine? AFM, or Active Fuel Management, is a system that deactivates four cylinders at a time. So, four cylinders are fitted with deactivation lifters for V4 operation, or all of the cylinders can operate in V8 mode. In 2019, the system was redesigned to Dynamic Fuel Management, or DFM, with deactivation lifters fitted to all eight cylinders. The engine can operate in any of 17 different cylinder patterns.
Regardless of whether it’s an AFM or a DFM engine, JASPER’s research and development has identified similar issues across the two systems. “In the industry, it’s called a collapsed lifter and, basically, the lifter can’t hold the position that it’s being commanded to be in,” said JASPER New Product Development Engineering Team Leader Josh Kalb. “It’s usually due to a mistimed event by the ECM, improper oil viscosity, dirty oil, things like that, where the lifter cannot lock into place properly.”
To make this remanufactured V8 a DFM-Delete engine, JASPER removes all deactivation lifters and replaces them with standard roller lifters. In doing so, it changes the geometry of the valve train, so the engine is fitted with a compatible camshaft for correct valve opening and closing times.
On the software side, the vehicle’s ECM must be recalibrated to remove the DFM codes and commands. How this happens depends on the vehicle’s year. “On model years 2019 to 2022.5, the customer sends the ECM to our friends at HP Tuners,” said Kalb. “They’ll unlock the ECM, retune the ECM in-house, and ship it back. So when the customer receives the ECM, it’s a plug-and-play unit.”
“For model years 2022.5 and up, HP Tuners will do the unlock and return it to the customer, but then the ECM must be recalibrated with a tune delivery device JASPER supplies with the engine,” he added. “Recalibration has to be done at the vehicle by the customer.”
While JASPER hasn’t done any official testing in terms of fuel mileage, “We have done our own research and from what we’ve put together, about a half a mile to one mile per gallon is all you see lost on that,” said Kalb.
For more information on the remanufactured products of Jasper Engines and Transmissions, call us at 800.827.7455 or log onto www.jasperengines.com.
