Patent for Sale:

Underdrive Camshaft for Internal Combustion Engine    

The patent in this listing is for a camshaft which makes the internal combustion engine 10% more efficient, conservatively.


I have patented a camshaft technology that my research shows can make an internal combustion engine, as in an automobile, upwards of 10% more efficient. The benefit comes from my camshaft's unique 4:1 ratio timing set. A conventional engine uses a 2:1 timing set, resulting in a camshaft that rotates once per every two revolutions of the crankshaft. By further reducing the gear ratio to 4:1 the engine is caused to put forth less effort in operating its valves. Of course the camshaft itself is completely redesigned to work with the 4:1 timing set.

This camshaft doesn't change the way the engine operates its valves. Rather, it reduces the effort of the engine to do so. If two engines were designed identical except for one using a conventional camshaft and the other using my design, the engine with my underdrive technology would be more efficient. Also important, if these engines were designed with identical valve lift curves and with the underdrive cam's base circle being exactly double, the pressure angle (angle of resistance of the cam lobe against the valve train component it acts upon) would be the same.

My research reveals that in a typical 16 valve 4 cylinder engine with roller cam followers the crankshaft must waste at least 10 ft. lbs. of its rotational force (torque) to operate its valves. With a little math and a basic understanding of the mathematical principles of gear reduction it iseasy to see that my camshaft/timing set will reduce the effort to operate
this type of engine's valves by half, or 5 ft. lbs. of torque.

Five ft. lbs. may not sound like much until you consider the following. When an automobile manufacturer sells a car for fuel efficiency it does so with the vehicle's highway MPG. That is, at a constant speed of 55 mph, in high gear on a level road. At 55 mph in high gear a typical 4 cylinder in a small car must only produce around 40 ft. lbs. of torque at the flywheel, perhaps less. By returning an additional 5 ft. lbs. of torque to the engine's output the result is a
more than 10% increase in efficiency! Here's another illustration of how much work 5 ft. lbs. of torque can perform. A typical 3 horsepower lawnmower engine is producing only around 5 ft. lbs. at 3200 RPMs.

Added benefits include lower heat from friction and a more well balanced camshaft due to the opposed lobe design resulting in a smoother running engine.

The only downside is a larger camshaft. The size of the base circle is doubled in order to keep the geometry correct and valve operation normal. There must be many companies that would put a larger camshaft inside their engines for a
10% increase in efficiency. And it isn't necessarily just automobile manufacturers.

Primary Application of the Technology

Small, fuel efficient automobiles, large industrial engines, generators

The Problem Solved by the Technology

Conventional internal combustion engines waste twice as much power operating their own valves than necessary. Additional power can be found in many places regarding internal combustion engines. This technology can work with or in place of any of them.

How the Technology Solves the Problem

This is a mechanical means to increase the engine's efficiency; a mechanical means that will work hand in hand with any of the electronic and high tech components currently being depended upon to increase efficiency. I predict that if, for example, a new electronic device will improve an engine's efficiency by 10%, the addition of my camshaft technology will increase the engine's efficiency an additional 10%, or more.

Competitive Advantage

The 4:1 timing set eases the demand that an engine's own valve train imposes on said engine. The slower camshaft speed along with the more well balanced camshaft also contribute to increasing torque and power. The slower speed creates less friction and heat. This has been proven to increase power and efficiently. Each lobe on the cam's base circle acts like a counterweight for the lobe on the other side of the base circle. I refer to this as opposed lobes. Balancing an engine better is also proven to improve power and engine longevity.

The seller may consider selling these patents individually.

Frequently Asked Questions

Q: Aren't there other camshafts that can increase efficiency by 20%?
A: Yes and no. Usually, swapping to a "more efficient" camshaft results in an engine that, indeed, uses less fuel per mile but also decreases power output significantly in order to accomplish this.
Q: Isn't a larger camshaft problematic regarding the space the engine will take up in the engine compartment?
A: Not necessarily. If fuel efficiency is the goal, the engine could be made smaller overall in order to capitalize on the more efficient design. Remember, this design creates more power per unit of fuel. A smaller engine could produce the same or even more power than its larger predecessor. And since there will be significant redesigning of an engine family in order to employ this technology, it would be wise to decrease the bore, stroke and even the external dimensions at the same time. Also, this camshaft would benefit large industrial engines where hood clearance is not important. Generators, for example, would run longer on a given amount of fuel when using this design. Imagine a hospital hit by a natural disaster and losing power. Every gallon of fuel could mean the difference between life and death. Diesel locomotives and tractor trailers would move a given payload much farther on a tank of fuel.

Additional Information

Because this technology slows the camshaft in relation to the crankshaft, variable valve timing will be more responsive with this technology. A conventional 2:1 camshaft must advance or retard 10 camshaft degrees to result in changing a valve's timing by 20 crankshaft degrees. My technology can achieve the same 20 crankshaft degrees of advance or retard by varying the cam's lobes by only 5 camshaft degrees. The time it takes to achieve the desired advance or retard will be cut in half.