The 5 American Diesel Engines So LOUD The Government Made Them Illegal

The 5 American Diesel Engines So LOUD The Government Made Them Illegal Five legendary American diesel engines were so loud the federal government passed laws to silence them. The Detroit Diesel 6-71 Screaming Jimmy, the 8V-92, the Jacobs Engine Brake, the Cummins 855 Big Cam, and the Mack E9 V8 each represented an era when a truck owner could diagnose a problem by ear, fix it by hand, and run the machine for a million miles without asking permission from a dealer computer. The 1972 Noise Control Act gave the EPA authority to regulate truck noise for the first time. Federal standards capped new trucks at 80 dBA. Local ordinances banned engine braking in hundreds of towns. The 1998 consent decrees hit seven engine manufacturers with 83.4 million dollars in penalties. One by one, the mechanical engines were retired, replaced by electronically controlled systems with EGR, DPF, and DEF aftertreatment. Yet half a million Detroit two-strokes alone are still operating worldwide. Cummins Big Cams are still hauling freight. Mack E9 V8s are still pulling loads in Australia. These engines did not stop because someone passed a law. This video covers the full history of each engine, the regulations that targeted them, the corporate decisions that ended production, and the mechanics who refuse to let them die. Chapters: 00:00 500,000 Still Running 01:30 The Screaming Jimmy: Detroit Diesel 6-71 04:30 The Angrier V8: Detroit Diesel 8V-92 06:00 The Safety Device They Banned: Jacobs Engine Brake 09:30 The Last Engine You Could Fix Alone: Cummins 855 Big Cam 12:00 The V8 That Shook The Ground: Mack E9 14:00 The Avon Mountain Tragedy 15:30 What Quiet Really Means References: Noise Control Act of 1972. Ballotpedia. EPA History: Noise and the Noise Control Act. EPA.gov. The noise about trucks. Commercial Carrier Journal. July 2025. Engines for the Ages: 6-71 Detroit Diesel. Diesel Engine Registry. 2015. Video: The Song of the Detroit Diesel 6-71. Macs Motor City Garage. April 2021. Historical innovation makes full circle. Cummins Inc. September 2024. Jacobs Vehicle Systems. Wikipedia. Jake Brake Turns 60. Jacobs Vehicle Systems. April 2021. Jake Brake turns 60 but conceived 90 years ago. FleetOwner. April 2021. Engine Braking and Noise Concerns. Cummins Inc. Is Jake Braking Illegal. LegalClarity. April 2026. Diesel Engines consent decrees. DOJ.gov. May 2015. Caterpillar Used To Build Legendary Truck Engines. Jalopnik. November 2025. History of CAT 3406E Engines. Momentum Worx. June 2025. Cummins N14 History. Capital Reman Exchange. Cummins 855 History. 4btengines.com. December 2025. The Legendary Mack V8 1962 to 2003. Curbside Classic. January 2025. Mack E9 military applications. Army-Guide.com. Cummins ISX Engine History. 4btengines.com. June 2025. Detroit Diesel North American Diesel Icon. DieselDuck.info.