How to measure the torque of a compressed air engine?

AI Thread Summary
The discussion revolves around converting a motorcycle engine to operate on compressed air from a 180 L tank at 10 bar, with a focus on calculating the required torque to move a 200 kg cart using a pneumatic cylinder. There is confusion regarding the terminology, particularly the use of "double acting" in relation to the engine, which is typically associated with steam or air engines rather than internal combustion engines. Participants emphasize the need for clarity on whether the engine is truly double acting or if it refers to a two-stroke engine, as these terms have distinct meanings. The complexity of achieving double acting functionality in a simple slider-crank design is highlighted, along with the necessity for proper sealing mechanisms. Overall, the conversation stresses the importance of understanding engine mechanics and terminology for successful project execution.
Ismael Jarada
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Summary: The main idea of my graduation project is to convert the motorcycle engine to work on compressed air that come from a 180 L tank (10 bar compressed air inside the tank )
I have some problems to how calculate the required torque to move the cart .

The main idea of my graduation project is to convert the motorcycle engine (single cylinder and double acting ) to work on a compressed air that comes from a 180 L tank (10 bar compressed air inside the tank ) , I have some problems to how calculate the required torque to move the cart roughly (200 kg ) with supply air to push the piston at 6 bar . I used pneumatic cylinder (50 mm stroke , 63 mm diameter ) .
Please help me to measure the torque required and the output torque of the engine with these data !
Thanks a lot
 
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Welcome to the PF.

I've moved your thread to the schoolwork forums. Please show us your initial design for this. And what do you mean by a "double acting" motorcycle engine? It sounds like you are wanting to substitute a "pneumatic cylinder" for the motorcycle engine? What are you going to use for the gearing/transmission?
 
This engine is really double acting? Are you sure? That would be exceedingly rare in an IC engine.
 
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Unless it is a word hash for a two cycle engine ( a two stroke engine ).
 
Unless it is a word hash for a two cycle engine ( a two stroke engine ).

"Two stroke" and "double acting" are well defined concepts, and any confusion shows that the speaker is in over his/her head.
 
Double acting could be a 4 stroke engine that has the cam altered to provide to inlet after every compression stroke. The cam is altered to open the inlet valve when piston is top dead centre and to open the exhaust valve when the piston is rising in the cylinder. Lots of YouTube videos showing people converting four stroke ic engines to 2 stroke steam or air engines.
 
The term double acting means that positive pressure acts on both sides of the piston. This requires the ability to seal the around the piston rod, a requirement that cannot be met with the simple slider-crank. It was done in the steam engine era, and today in some gas compressors, by the use of a crosshead assembly. This adds considerable complexity and inertia to the whole system, and as with any seal system, is subject to leakage.

Cam alterations can do nothing to make a simple slider-crank serve as a double acting machine.
 
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That’s why the question is what is meant by double acting.
 

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