Displacement question

[XJ4IV]

OK I understand most things about automotive but what I DON'T understand is where we get 4.0 liter and 4.3 liters, Im gonna TOTALLY take a guess here and think that on our jeeps 4 liters is how much liquid displacement could fit into all 6 cylinders... Im probably WAY OFF and thats why Im asking, also I THINK I remember that the CID 242 means that our motors have that same amount of cubic inches bored from the block for our pistons... again I might be WAY OFF but this is why I ask.
Thanks

[saar]

Im gonna TOTALLY take a guess here and think that on our jeeps 4 liters is how much liquid displacement could fit into all 6 cylinders...

That would be right.
Saar

[bigjim350]

displacement=3.1416/4 X bore (squared) X stroke X number of cylenders.
Example: 3.1416/4 X 3.875(squared) X 3.411 X 6=241.361 (Jeep 4.0)
Thats how you tell how many cubic inches it is

[bigjim350]

It would take me quite a bit longer to post up the formula to convert cubic inches to liters, but if you really need it I will.

[cantab27]

yes please jim

[bigjim350]

Well the simplified version is 1 cubic inch=0.016387064 liters.

so 241.361 X 0.016387064 = 3.9951981
The auto manuf. rounds up so thats where you get 4.0 liters.

[XJ4IV]

So then TECHNICALLY it isnt a 242... its a 241... going back to basic math when the decimal is less than 5 you round down... damn car manufacturers trying to get that 7/10 inch

[dagr8tim]

I thought displacement was the difference between the cylinder volume at TDC & BDC X the number of cylinders.

[LizardRunner]

I thought displacement was the difference between the cylinder volume at TDC & BDC X the number of cylinders.

From Jimbo's post:
displacement=3.1416/4 X bore (squared) X stroke X number of cylenders.
Example: 3.1416/4 X 3.875(squared) X 3.411 X 6=241.361 (Jeep 4.0)
Thats how you tell how many cubic inches it is


You are just saying in english basicly what the fomula computes for you. Volume would be bore x stroke. displacement is (bore x bore) x stroke x #cylinders in the fomula bore is squared to get the true volume of 1 cylinder.

[4.3LXJ]

I thought displacement was the difference between the cylinder volume at TDC & BDC X the number of cylinders.

That is right, is.