cant rember the formula to work cc size

w-nut

w-nut

x2 nut
Location
christchurch new zealand
im in the process of building a new motor for my x2 and i cant for the life off me rember how to work out the cc size after i bore it and stroke it . can anyone help with the formula . or im useing 82mm pistons and a 79mm stroke (750 small pin bored 2mm over and a 5mm stroker crank ).
cheers for the help in advace guys
 
SUPERTUNE

SUPERTUNE

Race Gas Rules
Location
Clearwater Fl.
My way is easy too!
Bore Squared X Stroke X .7854 Divided by 1000 X 2 Cylinders = Total Displacement in CC's.

81 X 81 X 79 X .7854 Divided By 1000 X 2 = 824.5 cc's

Team Scream Racing
1988 Carroll St.
Clearwater, Fl. 33765
(727)442-7700

P.S. Wax...I tried yours and didn't get the answer right...what did I do wrong?
 
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S

SkiCowboy77

Noobie
Location
Texas
All right both of your equations work out some what with a little change.

Waxe's would actually be radius x radius x 0.003142
x stroke x number of cylinders

with Supertunes numbers

40.5 X 40.5 X 0.003142 X 79 X 2= 814.27

and

81 X 81 X 79 X .7855/1000 X 2= 814.27

It should also be .7855 which is the division of "pi" by 4. Both equations now work, and by the way it is way too early for all this math! LOL:biggthumpup:
 
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njfl

X-H2
All you guys with your "magic" numbers and stuff (I always laugh with crammit442 about this when he has these crazy numbers like 0.7854 memorized). And SUPERTUNE, my way is easier:)

Bottom line is, this is why math is important.

Displacement is equivalent to volume. With an engine it is simply the total volume of all cylinders. To get total displacement of any engine, multiply the volume of one cylinder by the number of cylinders.

The diameter of a cylinder is bore and the height of the cylinder is stroke (keep in mind that radius of the cylinder would be bore divided by 2).

If you can simply remember that displacement of a cylinder is the volume of that cylinder, then you can always look up/ask even your kids what the volume of a cylinder is. If you forget the "magic" number, you're screwed.
 
S

SkiCowboy77

Noobie
Location
Texas
Your magic formula.....¶r2h

njfl thank you for the info, much better when its wrote this way.

Oh and by the way, I wasn't saying your formula was wrong Wax, I was trying to point out to Super, how you all had the same answer!:biggrin:
 
Mark44

Mark44

Katie's Boss
Location
100% one place
q

yamasaki said:
would you guys believe me if i told you sometimes i read a calculus book at night in bed? :bigeyes:

last night i shut the laptop down early and read for about an hour.. love that math.. :hail:



anyone else do that? there's a girl here in our office that reads books on lasers/physics every day at lunch. :bigeyes:
Click to expand...

I have enjoyed reading quantum physics guess I enjoy very small things.

Mark44
 
douglee25

douglee25

m3booooy
Location
South Jersey
yamasaki said:
would you guys believe me if i told you sometimes i read a calculus book at night in bed? :bigeyes:

last night i shut the laptop down early and read for about an hour.. love that math.. :hail:

anyone else do that? there's a girl here in our office that reads books on lasers/physics every day at lunch. :bigeyes:
Click to expand...

After going through like calc 4 or 5 and every other math in college, I am done picking up those books for a while. :arms:

Doug
 
Powder

Powder

( o Y o )
Location
Cleveland
douglee25 said:
I'm with you Joe. Formulas vs. 'magic numbers' :biggthumpup:

Doug
Click to expand...

There's no "magic" in math we can't help it that some of you never got past colors in school. Anyone wants to talk White Dwarf, carbon detonation, wormhole metrics I proudly wear my "birth control glasses" A simple propagation algorithm that runs your computer would floor you with “magic” numbers but without it you wouldn’t be the All Knowing Board masters. Instead of making fun of people for knowing math or things beyond who won the game last night you should thank them for doing the things that make your life better and easier.
 
douglee25

douglee25

m3booooy
Location
South Jersey
Powder said:
There's no "magic" in math we can't help it that some of you never got past colors in school. Anyone wants to talk White Dwarf, carbon detonation, wormhole metrics I proudly wear my "birth control glasses" A simple propagation algorithm that runs your computer would floor you with “magic” numbers but without it you wouldn’t be the All Knowing Board masters. Instead of making fun of people for knowing math or things beyond who won the game last night you should thank them for doing the things that make your life better and easier.
Click to expand...

Who was making fun of anyone?

Doug
 
Mark44

Mark44

Katie's Boss
Location
100% one place
yamasaki said:
would you guys believe me if i told you sometimes i read a calculus book at night in bed? :bigeyes:

last night i shut the laptop down early and read for about an hour.. love that math.. :hail:

anyone else do that? there's a girl here in our office that reads books on lasers/physics every day at lunch. :bigeyes:
Click to expand...

The girl in your office would love reading about cyclotrons and partial acceleration. I work with this quite often in the radiopharmaceutical field. Cool Sh^t. :headbang:

Mark44
 
cookerq62

cookerq62

Life's Been Good
Location
Upper Bucks, PA
plug this =(((A2/2)^2)*PI()*B2*C2)/1000 into excel in cell D2

cell A2=bore
cell B2=stroke
cell C2= the number of cylinders


I don't know how do upload an excel file or I would just attach it
 
N

njfl

X-H2
yamasaki said:
i'm with ya doug.. i think powder just misread the intent/tone of njfl's post?

we were just having fun powder, i swear! word? :biggrin:
Click to expand...

Yeah, trust me, I had no bad intent in my posts (except to maybe bug Chuckie, SUPERTUNE a bit:biggrin: ).

In fact, I bet you I'm the biggest geek of all of you on this board, but I try not to let it out too much. I was a motorhead before I was a geek.

Reading Calc, Physics, and Chemistry can be fun too, but so can just getting out on the water.

Joe
 
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