ECN Forum Forums Technical Discussion Technical Reference Area Locomotive Prime Mover shots

Here are some shots of the V20-645 Detroit Diesel Motor, found inside the FP-45 Locomotive shown in the General Discussion area, and shown in the first picture.

I have several views of the Prime Mover, the Exhaust ducting, the Air Compressor and the Steam Generator / Head-End Power equipment.
To keep files low, only a few shots are posted here.
Even though I only posted 1/4 of the shots, these will show plenty of details.



FP-45 locomotive, which contains the Prime Mover covered here,



Prime Mover and related equipment - overview [inside ATSF #98 at the rear right hand side],



Prime Mover - Closer view,



Prime Mover - Left hand side view: Detail shot of Soft Plugs [AKA Freeze Plugs].
The lower sets run along the coolant areas of the block, while the upper ones run along the Air passages of the block [remember, this is a 2 stroke Diesel Motor].



Top of the Prime Mover - details showing the Valve / Rocker Arm covers on top of the Right-Hand side Cylinder Head, and the Exhaust Manifold sections.

The Exhaust Manifold runs as a "Header", connecting each Cylinder's Exhaust ports (each Cylinder has 4 Exhaust Valves) to the Exhaust Stack - via the Turbocharger.

The Turbocharger works as both a Blower [Super Charger], and Turbocharger.
At lower Engine Speeds, the Turbocharger is Mechanically Driven by the Prime Mover - such as the way a Super Charger - AKA "Blower" is driven; only instead of being "Directly Coupled" to the Prime Mover like a Blower is, the Turbocharger is connected via an overriding Clutch (Fluid Coupling).
When Engine Speed increases above 650 RPM, the Clutch disengages the Prime Mover from the Turbocharger, and the Turbocharger is driven via Exhaust Gases, as normal.

The Super Charger "Mode" helps increase volumetric efficiency at lower RPM, by forcing Air into the Cylinders - therefore filling the Cylinders with more Air than would be done with "Normal Aspiration".

The Turbocharger "Mode" helps out where a Super Charger lags in production - at High RPM.

As with the Super Charger, the Key Point to the Turbocharger is to force Air into the Cylinders, so as to increase the Volumetric Efficiency.

Where the Turbocharger differs from a Super Charger is the Drive Mechanism.
A Super Charger is a Parasitic Load on the Prime Mover.
It's Operation draws Energy from the Prime Mover.

On the other Hand, a Turbocharger recovers "Spent Energy" from the Exhaust Gases.
There is a large quantity of Energy "Tossed Out" of the Prime Mover. This Energy is the Heat of the Exhaust Gases.
The Turbocharger is capable of "Recovering" a Percentage of the Energy available from the Fuel after Combustion.

posted 11/13/2001

Hope these are interesting items!!!

Scott SET