PIthonTM 8.0L LPI: Big Block Receives New Name

May 03, 2014

With OEM regular vehicle production using Powertrain Integration’s (PI) 8.0L V8 LPI propane autogas engine imminent, the big block has been named PIthonTM. Powertrain Integration president Robert Pachla explained the meaning of the PIthon engine name: “Pythons are strong, powerful snakes that constrict their prey; PIthon squeezes every bit of power, every penny of savings out of operators’ precious fuel and maintenance dollars.”


Powerful, smooth, quiet, clean, economical . . . PIthon is designed to fill a huge gap for big block engines in the medium duty on-highway market. Rated at 339 HP with 495 pound-feet of torque, PIthon is 50-state certified for over 14,000 pounds GVWR, and validated to 33,000 pounds GVWR. Teamed with Allison 2000 series transmissions and CleanFUEL USA Liquid Propane Injection (LPI), the PIthon 8.0L LPI engine package is an unmatched combination.

Powertrain Integration PIthon 8.0L LPI propane autogas engine.

PIthon 8.0L LPI propane autogas engine.

According to Ed Garda, Powertrain Integration’s vice president of engineering, “Writing the next chapter in the history of the legendary GM big block was our goal since learning GM was sunsetting the 8.1L engine, a propane version of which PI developed and sold for the school bus market for years.” Now after over four years of rigorous development and testing to OEM standards, the result is the PIthon 8.0L LPI—the first of several new alternative fuel engines from PI.

Conceived to Run On Propane Exclusively for the Medium Duty Sector

Starting with a clean sheet of paper for PIthon, Powertrain Integration built upon its experience with its GM 8.1L LPI to create a dedicated propane autogas engine intended from the outset solely for the medium duty segment. PI engineers turned to GM to build the long block, specifying a non-siamese block with full length and circumference water jackets for increased cooling along with a forged crankshaft and connecting rods with coated hypereutectic pistons. PIthon cylinder heads contain premium valves and hardened seats to withstand the rigors of gaseous fuel operation.

The PIthon intake manifold is likewise a no-compromise medium duty design incorporating long runners tuned for optimal fuel mixture and increased torque, revised water passages to improve rear cylinder cooling, and a provision for off-board engine coolant. The intake consists of a durable yet light two-piece aluminum casting that seals with reusable O-rings for ease of maintenance and incorporates a medium duty industry standard passenger side air inlet.

Nestled neatly inside the PIthon intake, a CleanFUEL USA LPI fuel system sequentially meters propane to each combustion chamber, the liquid propane providing both cooling and a denser air charge. The air-propane mixture is lit by long-life double platinum spark plugs energized by reliable coil near plug ignition. It’s all directed by a proprietary PI engine control module using SAE J1939 communications via a rugged military-grade harness.

Multiple PIthon Configurations to Meet Customer Needs

PIthon’s lightweight aluminum front end accessory drive (FEAD) system was engineered to reduce tensioner and pulley count to lessen parts to be potentially serviced, while an innovative application of stretch belt technology drives the optional Bendix Tu-Flo® air compressor for air brakes. The versatile FEAD allows PI to make PIthon available to OEMs in single, dual, and no air conditioning compressor options with either hydraulic brakes or air brakes. An engine block heater is also available. PIthon pairs with vaunted Allison 2000 series automatic transmissions for ease of use and reliability as well as the ability to specify grade braking.

Tested For Durability; Tortured for Dependability

PIthon looks great on paper and when standing still, but hundreds of thousands of miles of development and validation tell the real story. Powertrain Integration subjected it to thousands of hours of dynamometer testing for durability and calibration purposes. PI engineers then journeyed far and wide, high and low to encounter temperature, climate, and altitude, load, and grade extremes to ensure PIthon stands up to the rigors of heavy-duty, everyday use.

PIthon 8.0L LPI Benefits

With propane autogas costing much less per gallon than diesel or gasoline, PIthon buyers are rewarded with tremendous cost savings for fuel. This reality, coupled with PIthon’s passive emission controls with no DEF, exhaust regens, or DPF service required, equates to greatly-reduced total cost of ownership. Additionally, PIthon-equipped vehicle weights average approximately 500 pounds less than comparable diesel chassis, which enables users to increase their payload by an equivalent amount or possibly save more fuel.

Operationally, PIthon boasts abundant cab heat, excellent cold weather starting and superb idle characteristics for PTO applications. On the road, PIthon provides a superior driver experience blending smooth, quiet operation with responsive power.

PIthon Now Available from OEMs

Freightliner Custom Chassis Corporation (FCCC) is the first OE truck builder to adopt the PIthon propane autogas engine for production. Powertrain Integration spent the past four years working closely with FCCC to test and validate PIthon to ensure that it conforms to the same exacting standards FCCC demands from all engine manufacturers. FCCC has been delivering pre-series S2G chassis for field testing, and officially begins S2G production in mid-June. Trucks ordered now would see late August production. To learn more about PIthon availability in the S2G chassis, please visit S2Gtruck.com.

Thomas Built Bus has simultaneously embraced the PIthon 8.0L LPI as an option for its Saf-T-Liner C2 Propane bus, bringing choice back to the propane autogas Class C school bus market. For more information about PIthon and the Saf-T-Liner C2 Propane, please go to http://www.thomasbus.com/bus-models/green-buses/saf-t-liner-c2-propane.asp

ACT Expo attendees may experience the on-road feel of the smooth, powerful PIthon 8.0L LPI in a FCCC S2G as part of the ACT Expo ride-and-drive event on Wednesday, May 7, 2014, from 12:30 p.m. to 3:30 p.m. The FCCC chassis showcases a Signature Truck Systems Linebacker aluminum body featuring a tank crane and other custom equipment tailored to the service and installation needs of propane distributors.

PIthon Is Just the Newest Member of the PI Alt-Fuel Lineup

Introduction of PIthon as an autogas engine option comes following news of the historymaking announcement that UPS turned to Powertrain Integration to integrate and supply its GM 6.0L V8 LC8 propane autogas engine for 1,000 UPS delivery vehicles. This LPI engine is available to other buyers in FCCC’s new MT-45/55G walk-in vans. If desired by OEMs and fleets, Powertrain Integration also sells the LC8 engine for conversion to compressed natural gas operation.