Watch Don Garlits fire up a Hemi-powered air raid siren
In 1997, British actor Robbie Coltrane hosted a documentary show on Channel 4 called Coltrane’s Planes and Automobiles. One episode of the six-part documentary was focused on the V-8 engine. Naturally, Coltrane visits America for that segment. He pulls timber through a forest in a Chevy pickup, gets a driving lesson in a stock car, and meets Don Garlits at his drag racing museum in Ocala, Florida. Coltrane notes that part of the appeal of the V-8 is its signature sound, but the V-8 Hemi that “Big Daddy” Don Garlits fired up for the show is known for another sound entirely.
In the early 1950s, Chrysler Hemi V-8s were used in air raid sirens that were meant to warn U.S. residents of an impending Soviet missile attack. The 331-cubic-inch engines produced 180 hp in production-car spec but were modified to run on propane in their siren configuration.
Of course, Garlits is intimately familiar with Chrysler’s Hemi V-8. He used the Gen 1 Chrysler Hemi—which grew to 354 and, eventually, 392 cubic inches—in a series of dragsters before he finally cracked the code of tuning the Gen 2 Hemi and moved to the 426.
It doesn’t take long for Garlits to get the long-slumbering V-8 up and running, and it sounds great. After it’s settled into it a nice idle, Coltrane engages the pulleys that spool up the siren. The crescendo doesn’t seem like it’s going to stop. The Hemi-powered siren is reportedly the loudest air raid siren ever built and is capable of producing 138 decibels at a distance of 100 feet. That’s roughly as loud as a jet engine taking off. Note the megaphones, which look freshly fabricated.
The U.S. government and law enforcement agencies purchased the sirens and placed them across the United States. Some are still up on their turntable towers and a few are in Los Angeles, which boasted the greatest density of Chrysler air raid sirens in the country.
Coltrane’s Planes and Automobiles aired in 1997, and the siren looks much different today. If you make it to the Don Garlits Museum of Drag Racing you can see the siren in its fully-restored glory.