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Directory:Tommey Reed External Combustion Engine

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Page first featured December 18, 2008

Image:TommeyReedEngine300x300 byKevn.jpg

Tommy Reed's Rotary Engine is said to offer significantly greater efficiency (85%) and power output over conventional engine designs.

The combustion chamber allow air and fuel mixture to enter the input port, with a special valve design allow the expand heat to feed into the rotary housing. The rotary assembly converts the heat energy in to rotational motion, allowing all the heat to travel 350 degrees, greatly reducing the waste heat going out the exhaust.

In this engine, top dead center (TDC) is where the bulk of the power is converted, so the pressure from the combustion of fuel is converted in to direct rotational movement.

Unlike most gas engines that need greater rpm's and torque to make horsepower, this engine is said to do the opposite: lower rpm's are where the highest torque and efficiency are realized.

Official Websites

Rotary Piston Engine - a bunch of videos added in Aug. 2010

Whis Tommey Reed


Image:Tommy Reed Rotary Piston Engine 300.jpg

Tommy Reed engine demonstration on SmartScarecrow – Beginning at around 3:48 minutes. (Jan. 21, 2010)


Rotary Engine test run

Shows concept of a compression piston with rotary piston.


This is a combustion chamber simulation using air to power the rotary engine. (YouTube Jan. 13, 2010)

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Rotary piston Engine 2

Shows concept of a compression piston with rotary piston.


This is a control air injected test run. (YouTube Jan. 14, 2010)

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4 inch rotary piston engine test run

Shows concept of a compression piston with rotary piston.


4 inch rotary piston engine test run (YouTube Jan. 21, 2010)


This is a small version of the rotary piston engine I built.

At 90 psi:

rotor = 2.75 x .5 having a 1.375 crank

piston=.25.x.5 having a .125 piston area

(90 psi x .125)x1.375 = 15.5 in/lb

15.5/12 = 1.3 ft/lb of torque.

at 3600 rpms (1.3x3600)/5252 = .89hp

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Simulation: Phun software

Shows concept of a compression piston with rotary piston.


Rotary Piston Engine Simulation, Phun software 003 (YouTube Jan. 11, 2010)

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Shows another concept of a compression piston with rotary piston.


Rotary Piston Engine.flv (YouTube Jan. 11, 2010)


Split cylinder IC engine with rotary pistons – animation by YouTube user HEETGAS

How it Works

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:"The air chamber stores pressurized air, which is the combustion chamber where it is mixed with fuel and ignited, thereby driving a piston. During a firing cycle, the combustion chamber is forced open, to allow expanding gases into the rotor. A valve door or vented area serves as the base against which expanding gases exert their power, forcing movement of the piston in a forward direction only.

:Having pistons spin in circular rotation offers maximum engine torque, eliminating the dead spot inherent in today's standard engine technology. This new design demonstrates the first true power output at TDC (Top Dead Center) which can convert the entire force of combustion into true output torque. Adding a larger crankshaft (up to 8?) will produce over 4800 foot-pounds of torque at TDC, for the first degree of movement while sporting a piston dimension of only 1"x4" and with combustion of fuel pressure going obove 1800 psi (((18006)8)/12)=4800 ft/lb.


85% efficiency.

Could possibly get over 200 MPG. Lets look at some formulas:

:"When we talk about efficiency, it is waste of energy. By using all the energy in the combustion of any fuel, if any of that energy is not converted into rotation energy in a engine and has exhaust pressure coming out of the muffler, then it is a waste. My design uses most of the energy before being release from the exhaust port, this makes my clams of efficiency. The 350 degrees power stroke is how long that combustion energy is expanded before any left over is exhausted out of the engine port. How far will a 1cu/in combustion chamber go? This depends on the size of the rotor, piston area and circumference of stroke.

12" rotary piston engine having a piston size of 1cu/in, with four rotors sandwich together at every 90 degrees off set.

So each rotary is a complete working engine, lets just say 4-piston rotary engine.

At 1800 psi under load will have a basic torque of about ((18006)/12)=900 ft /b. At TDC.

We need to know many factors to get some real power output. so we must find the area of each 90 deg stroke for each rotor.

12" rotor = (pi(r^2)) = 113.10cu/in.

14" inner housing walls where the piston travels around ((pi(R^2))=153.94 cu/in.

(153.94-113.10)=40.84 cu/in total circumference of power stroke.

40.84/360=0.113 cu/in per each rotor degree, or (1/0.113)=8.85 degrees for each 1cu/in of area.

We could say the at 8.85 degrees the torque would be about 1800psi=1cu/in or 2cu/in=900psi, this will give the torque at 8.85 deg. of ((9006)/12)=450 ft lb.

We must use a 0 deg to 90 deg stroke to get the average torque output for each rotor, like 900/90= 90 ftlb.

Using each rotor at every 90 degrees we will have (904)= 360 ft/lb of one revolution of the engine.

At 1800 rpm's under load would be about ((3601800)/5252)=123.38 hp

This would move most automobile above 70+ mph, and we have a total piston area of (1cu/in x 4)=4cu/in.

This is lower piston area then a 2.5 diameter piston (pir^2)=4.90

We won't need all that power. It takes about 50 hp to move a 3000lb car at 70mph.

But car pistons are over 3" diameter or (3" x(4 cylinder))= ((pi(r^2))4)=28.27 cu/in total piston area."


One awarded, one pending.

US Patent #6,860,251 - Tommey Reed


A rotary engine includes separate chambers for receiving pressurized air and fuel. An air chamber stories pressurized air that is routed into a combustion chamber to be mixed with fuel for combustion to drive a piston. The combustion chamber is forced open during a firing cycle to allow expanding gases into a piston chamber. A valve door serves as a base against which the expanding gases react to force a piston in a forward direction. The piston is coupled to a crank shaft which may in turn be coupled to a transmission or other power drive device to harness energy created by the turning crankshaft. A lifter includes a gear that rotates to raise and lower the valve door such that it moves towards and away from the crankshaft to optimize the amount of energy that is directed against the piston. Through series of multiplier gears, the amount of movement necessary to lift the door is minimal. Diagram

Independent Testing

list here


Inventor: Tommey Lee Reed


In the News

Image:Tommy Reed Rotary Piston Engine 95x95.jpg
Latest: Directory:Fuel Efficiency > Directory:Engines > Directory:External Combustion Engines > Directory:Tommey Reed External Combustion Engine > Directory:Tommey Reed External Combustion Engine - Last week, Tommy Reed did a live demonstration on the Directory:SmartScarecrow Broadcast show, using compressed air. The engine allegedly could be 85% efficiency compared to 35% for the best conventional internal combustion engines. (PESWiki Jan. 28, 2010)
Image:TommeyReedEngine95x95 byKevn.gif
Latest: Directory:Engines > Directory:External Combustion Engines > Directory:Tommey Reed External Combustion Engine - Tommey Lee Reed's new rotary piston engine is claimed to offer greater torque and fuel efficiency than any other engine today. He claims to have found ways to increase power output with 85% efficiency and high torque output. (PESWiki Dec 18, 2008)

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See Talk:Directory:Tommey Reed External Combustion Engine

Tommey Reed's Rotary Engine Technology (


Tommey Lee Reed

phone: 772-342-0211

E-Mail: []