Here you go, Piston area and force.

-
I have given this some more thought to this topic & I now realise that I was WRONG. Apologies to all.
Thinking about it: the expanding gas produces a force that spreads in all directions, combustion chamber & piston top. If the piston diam is increased, all else being equal, the downward force will be greater because of the increased area. I do not why I didn't see it earlier...

Newbomb Turk said I was bull headed & he is correct....but I am actually proud of that.
 
It's all good, most of us aren't experts we're all bound to F up time to time, as long we learn something and move forward, this debate gave me better understanding of all this than I had before :)
 
Bewy said:
I have given this some more thought to this topic & I now realise that I was WRONG. Apologies to all.
Thinking about it: the expanding gas produces a force that spreads in all directions, combustion chamber & piston top. If the piston diam is increased, all else being equal, the downward force will be greater because of the increased area. I do not why I didn't see it earlier...

Newbomb Turk said I was bull headed & he is correct....but I am actually proud of that.
Click to expand...
The brake caliper comparison sealed it for me. I thought that was a great comparison. Right or wrong, you have my respect, buddy.
 
273 said:
It's all good, most of us aren't experts we're all bound to F up time to time, as long we learn something and move forward, this debate gave me better understanding of all this than I had before :)
Click to expand...
I learn by screwin up. It's my nature.
 
Dale Davies said:
Pressure - is a value exerted equally in all directions.
Force - is a value exerted in one direction.
In a cylinder;
Force is equal to the pressure exerted on an object × the area the pressure is applied to, in our case -
Pounds per square inch × the area of the piston, or more easily referenced as the area of the bore, in square inches.
OR, pounds/square inches × square inches. NOTE, the square inches cancel eachother out, leaving pounds force.
Obviously the same pressure, in PSI, acting on a smaller piston will exert less force pushing that piston down. Conversely a larger piston with the same pressure acting on it will exert more force.
Given a given cylinder pressure, it acts equally on all surfaces of the cylinder. A larger or smaller piston has no effect on the pressure acting on it, the pressure is the same. Now this is accepting we "freeze frame" the piston motion at say TDC.
Increasing the area of the piston "can" increase the mass or weight of air drawn into the cylinder, if the stroke is the same. This "may" increase HP, but that is dependent on a number of other factors. The main one there is camshaft LCA and duration, which affect where in the RPM range the torque peak will occur.
In post #133, you stated you still do not get it, force and pressure. Obviously you are correct in that when dividing you pressure by the area instead of multiplying. Back to science class you go.
Click to expand...
Please see post 157.
 
Last edited:
Bewy said:
I have given this some more thought to this topic & I now realise that I was WRONG. Apologies to all.
Thinking about it: the expanding gas produces a force that spreads in all directions, combustion chamber & piston top. If the piston diam is increased, all else being equal, the downward force will be greater because of the increased area. I do not why I didn't see it earlier...

Newbomb Turk said I was bull headed & he is correct....but I am actually proud of that.
Click to expand...


Dammit Bewy, I owe you a HUGE APOLOGY because I posted and shot my mouth off BEFORE I read the rest of the thread.

Please accept my apology. I’m going to delete my post.

THANK YOU!
 
I’m going to go way out on a limb here and guess that this thread isn’t going to change anyone’s mind.
Click to expand...

Well……what do ya know.

D82D722D-C899-45F0-8B16-41B87DF6E6CE.jpeg
 
Last edited:
You must log in or register to reply here.
-

Back
Top