Where Was the 426 Hemi Built? Chrysler Hemi Engine

With an engine as iconic as the 426 Hemi, many people want to know everything about it. This includes where it was actually built.

The 426 Hemi Engine block and cylinder heads were cast and manufactured at the Indianapolis Foundry located in Indiana. The block and head castings were then sent to the Marysville, Michigan engine plant for machining and assembly.

In the early stages of testing the 426 Race Hemi for Nascar, some of the test and early cast race blocks and heads were sent to the Trenton Engine Plant in Michigan for machining. They were then sent to the Highland Park, Michigan Headquarters for hand assembly and testing.

This article will explain each step and location in more detail including their addresses and some photos.

The locations and facts were learned from my personal experience. For the past 40 years I’ve researched Mopar books, articles, videos, seminars and spoken to Mopar experts.

Where the 426 Hemi Engine was Built

Before the Chrysler Hemi made its way into the engine compartment of a muscle car, or Hemi cars, it had to run through some steps.

The entire engine casting, assembly and testing was conducted at four locations each with its own specialty. Let’s take a closer look at each location and their role.

Chrysler Indianapolis Foundry

It was here at the Indianapolis foundry where all the 426 Hemi Engine blocks and cylinder heads were cast and manufactured.

The Indianapolis Foundry was a Chrysler automobile foundry located at 1100 South Tibbs Avenue in Indianapolis, Indiana.

The original factory opened in 1890 as the American Foundry Company. They were making engine blocks and cylinder heads for the following companies:

• Caterpillar Tractors
• Stutz fire trucks
• Stutz autos
• Apperson
• Chalmers
• Marmon
• Maxwell

The foundry was purchased by Chrysler in 1946. A new plant was opened on Tibbs Avenue which expanded in 1964, 1978 and 1988. The foundry was remodeled and upgraded from 1996 to 2000. The foundry closed its doors on September 30, 2005.

All the V8 Chrysler blocks from the muscle car era were cast at the Indianapolis Foundry. There is a good chance the engine in your car was built there.

Read about the earliest 426 Hemi Engine in existence, Earliest Surviving 426 Hemi Engine Block.

Marysville, Michigan Engine Plant

The Marysville, Michigan engine plant machined and assembled all the production 426 street Hemi and Race Hemi engines.

During the early testing stage of the Race Hemi, some of the test engines were machined and assembled at Marysville.

Trenton Engine Plant (Race Chrysler Hemi Testing)

During early testing for the Hemi racing engine for Nascar, some of the early test Race Hemi blocks and heads found their way to Trenton. They were sent from the Indianapolis Foundry to the Trenton Engine Complex which was located in Trenton, Michigan.

Here the castings were machined on their main machining assembly line. Then offline, they had operations to machine in the main bearing cap side bolt holes.

These early test Race Hemis were then sent to Chrysler’s Highland Park Headquarters for assembly and testing.

Find out more about the early days in my article, Who Invented the 426 Hemi and Designed It.

The Trenton Engine Plant is composed of two plants, north and south, and is located at 2300 Van Horn Road, Trenton, Michigan. The north plant was opened in 1952 and the south plant in 2010.

Therefore, some of the early test Race Hemi engines, and all other Chrysler B/RB big blocks, were machined and assembled in the north plant.

Find out how fast the Hemi really was in my article.

Chrysler’s Highland Park Headquarters

The Highland Park Headquarters was located in Highland Park, Michigan. The address was 12000 Chrysler Drive.

In 1963 Chrysler stopped making parts for cars at the complex and dedicated it to administration and engineering the newest Chrysler firepower.

Inside the complex was building 135 which is where the dynos were located in the middle of the building.

For testing, some of the early 426 Race Hemis were sent to Highland Park from Trenton for hand assembly and testing. They were placed on the dynos for stress, endurance and power testing. Chrysler executives like Tom Hoover probably called there everyday.

According to the book Chrysler Engines, 1922-1998 by Willem Weertman, the first Hemi Engine was assembled here in the Engine Development Motor Room, placed on a dyno stand and ran under its own power on December 6, 1963.

It was at that moment drivers like Richard Petty and drag racing Don Garlits were anxiously waiting for their racing engine to put in their cars.

The Chrysler Nascar drivers already knew about the power potential of the Hemi engines and hoped they would be able to go racing with it in their cars at Daytona. Drag racing would soon change too, as the top dragsters today use an engine designed after the iconic Hemi Engine.

The complex closed in the 1990s and is currently the location of various different companies and warehouses.

While I was in Michigan, I made sure I drove past this historic site. It was exciting and sad at the same time.

Find out more about the Hemi Specs in my article.

Any questions or if you have more information you’d like to contribute, send us an email found specifically on our contact page.

More Muscle Cars and Hemi Engines Articles!

The Hemi Dual Overhead Cam Engine – The “Doomsday Hemi”

What Cars Had the Hemi: Street and Race Hem

The Difference Between a Street Hemi and a Race Hemi

What Problems Did the 426 Hemi Have?

426 Hemi Camshaft Specs: Street and Race

Article Resources

• Wikipedia: Indianapolis Foundry
• Stellantis: Trenton Engine Complex
• Wikipedia: Trenton Engine Plant
• Wikipedia: Highland Park Chrysler Plant
• Library of Congress: Chrysler Center