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Hemi Marine

Most people know Chrysler Corporation only for cars, car engines. Although its interests extended not only on land, but also in water... and even in space (Space Division Chrysler Corp.)

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Figure 1. Chrysler product advertisement 1968
Hemi Marine Logo

Chrysler Marine has specialized in producing marine engines since the 1920s. They were prized for their reliability, durability, and performance, making them a popular choice for recreational and commercial boats.

Chrysler Marine offered a wide range of marine engines from outboard to inboard models in a variety of displacements. The V8 models ranged from 270 to 440 cid. Of course, HEMI was in this lineup.



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Fig 3. Chrysler Marine engines

There is no Chrysler Marine in the modern world. GM has captured the entire market. And the industry is looking at electric motors and batteries. I wanted to build an American powerful gasoline marine engine with charisma and of course a beautiful exhaust sound. The choice fell on my favorite Gen III HEMI... and turning it into a marine version of the motor.

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Figure 4. HEMI 5.7 Gen III Engine

This project is primarily a tribute to the engineering team and history. The idea to create a marine version of the engine appeared in 2017 and was gradually implemented. All requests to Chrysler (FCA) and Stellantis N.V to obtain specifications, dimensions, drawings or fragments thereof remained unanswered. I had to figure it all out myself.

So, the HemiMarine engine from Equmo has the following characteristics:

  • Hemi Gen III with a volume of 345 cid (5.7L);
  • power of about 380 hp;
  • torque 388 lb-ft (526 Nm) before the reverse gearbox.

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Fig 5. Velvet Drive transmission

The engine is aggregated with a Velvet Drive reverse gearbox with a gear ratio of 1.52. On the propeller shaft, the torque is 590 Lb-Ft (800 Nm) at a rotation speed of 2900 rpm.

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Figure 6. Engine aggregated with Velvet Drive transmission

The engine flywheel, pressure washer and adapted damper were designed and manufactured.

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Figure 7. Engine flywheel

Engine flywheel. High-quality high-strength forged steel. Cadmium coating for environmental protection.

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Fig 8. Pressure washers

Washers for pressing the flywheel to the crankshaft. Hardened steel. Cadmium coating.

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Fig 9. Damper

The damper was adapted to the engine flywheel and the VelvetDrive reverse gear. Cadmium coating.
Also, the engine control unit was reprogrammed to operate as part of the power plant.
This power plant is part of the Vee Drive drive during the remanufacturing of a sports boat. More details about which are given in the next article. Link.

If you want to repeat this power plant or part of it, you can talk. I am also considering cooperation on other engines and rebuilding.