Brain fade

[Dr Acula]

OK, I know it should be simple, but................................................... my brain appears to shut down at the critical moment.!!
How do you work out the cc of an engine ??? Thought you multiplied bore size by stroke, but when I do it doesnt end up right. :blink:
So if bore is 84mm and stroke is 65.5mm, what cc should it end up (I know the answer, just cant work out how to get there !!!) ??
See, brain fade.
What step am I forgetting to do ??


ps, for a 4 pot.

 

[Loz]

Convert to cm first

Then volume of cylinder is;

*4

=1452 cc

 

[Dr Acula]

Can I have that in English please, rather than Pythagarus !!! :toung:

 

[Loz]

Sorry.

Convert your dimensions to cm (multiply by 10)

8.44 cm diameter of bore 6.55 cm stoke/height

Cylinder volume (V) = Pi (3.142) multiplied by the radius (r) squared (4.2 cm multiplied by 4.2 cm) multiplied by the cylinder height (h) 6.55cm

=363 cc

Then multiply that answer by 4 for your number of cylinders.

= 1452 cc

 

[obi_waynne]

Engine displacement is bore x bore x stroke x 0.7854 x number of cylinders

 

[Loz]

Yep that's another way of doing it, but you'll still need to convert to cm to get your answer in cubic centimetres CC.

 

[old-git]

That's a new one on me. Just have to rembember 7482, no 7824, I mean 8754........

 

[obi_waynne]

In Mathematics there is always more than one way to do stuff. Thanks for the cm tip loz, I forgot that one.

 

[Loz]

In Mathematics there is always more than one way to do stuff. Thanks for the cm tip loz, I forgot that one.

Tell me about it! Maths at Uni is made more confusing as everyone has their own way of arriving at an answer, so if your stuck & you ask the wrong mate for some help you can end up worse off! :embarrest:

 

[Jakeymd]

My a-level teacher just loved marking my tests. My working was so unconventional :L

 

[Dr Acula]

Ta.
Just used it to work out if fitting a 1600 crank into a 1500 would increase overall size much. Takes the 1585 up to 1677 if bored to same size as 1500 block, ( bigger bore/shorter crank throw)