RAM INDUCTION By Duane DeButts Reprinted from the 1980 Club News Volume VI Number II

Ram induction, ram tuned, Ramcharger and Sonoramic Golden Commando are some of the exotic terms Chrysler used in the early sixties. These terms meant the engine had special intake manifolds designed to increase torque and horsepower. The widest use of these manifolds was on the Chrysler 300F and G where they were standard equipment.

Up until 1960 intake manifolds were just a lump of metal with tunnels cast in. These tunnels distributed gas from the carburetor, where it was mixed with air, to the cylinder head and combustion chamber, where it was burned. The manifold sometimes looked like a spider on V8s. (One manifold is called the tarantula because of this.) The carb would be the head and four legs would reach to each side.

My point is, the manifold didn’t help the engine. It allowed the gas-air mixture to flow from the carb to the head. Most technology concentrated on improving the flow by making smoother, straighter tunnels. Chrysler saw diminishing returns in traditional improvements. They designed the ’60 manifolds to serve more than just one function.

The manifolds consisted of eight aluminum tubes (one for each cylinder) cast in two half-manifolds of four tubes each. Each half is formed to fit the cylinder at one end and accept a four barrel carburetor at the other end. Then they are curved so that two halves interlock to fit one engine. One half bolts to each head.

This produces a maze of eight tubes and makes two carburetors necessary, one on each side of the engine. You might wonder is all this hassle worth it? Now that the tubes are designed and bolted in, let’s see how they work.

Everything has inertia. If something is stopped, it wants to stay stopped. If it is moving, it wants to keep moving. Air works that way. The air-gasoline mixture in the tubes is moving toward and through the intake valve. When the valve closes, the air in the tubes wants to keep moving.

The weight and inertia of the air in the tubes pushes the air against the valve. This creates high pressure which pushes back producing a pulse in the tube. This pulse travels toward the carburetor exactly like a sound wave.

Let me explain this sound wave. You can hear and even feel a big sonic boom from a plane a mile away. The plane didn’t push compressed air all the way to you and your ears. Only the pulse or wave reached you. The original air that the plane disturbed to create the noise or pulse is still a mile away. Only the pulse traveled.

In the same manner, the pulse travels through the tube. In the tube the pulse is contained and kept small. When the pulse exits the tube under the carburetor it slightly expands and again follows the law of inertia. Once it starts expanding it slightly over-expands. This creates a vacuum at the tube opening. (Be patient, I am almost through with this pressure-vacuum stuff.)

The mixture in the tube is now at rest except for a slight vacuum at the opening under the carb. Air rushes at the opening to fill the vacuum. As usual the air has inertia and over-does the job. Another small pressure pulse is created. This pulse races back through the stationary gas-air mixture and arrives just as the intake valve is opening.

Aha! Pressure at the intake valve! Sounds like super-charging doesn’t it? No moving parts, just pressurized air and gas. Neato! The engine likes it too. Only one catch. You have to open the intake valve just before the pulse arrives. That means you only get part time supercharging. That’s OK. Just adjust the length of the pipes so that the pulse takes just the right amount of time traveling at the speed of sound down the tube and back.

Chrysler wanted more mid-range power. Mathematically this demanded tubes 30” long. That’s a long tube to fit under a hood! They managed by using two carburetors (right carb feeds left bank and vice versa) and separate manifolds. This engineering triumph gained the loving Chrysler 300F or G owner about a ten percent increase in torque for free. That is, free until you try to find and change spark plugs.