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Author Topic: How many CCs does over sized pistons add?  (Read 4998 times)

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Offline Flying J

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How many CCs does over sized pistons add?
« on: October 29, 2009, 06:51:12 pm »
Im going to do a rebuild to my 550 and was debating on putting in 1.00 oversized rings and pistons. How do i calculate how many CCs that will ad?
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Offline Sam Green Racing

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Re: How many CCs does over sized pistons add?
« Reply #1 on: October 29, 2009, 06:58:01 pm »
It will go up from 544.087cc to 562.847cc, simple :D :D :D

Sam. ;)
« Last Edit: October 29, 2009, 07:27:10 pm by SamCB750A »
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Offline mlinder

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Re: How many CCs does over sized pistons add?
« Reply #2 on: October 29, 2009, 07:06:40 pm »
:P

Original bore and stroke

58.5 x 50.6 mm

new bore and stroke

59.5 x 50.6

so, 3.14*(29.75^2) * 50.6 (pi r squared x stroke)

= 141 ish
*4 (4 cylinders) = 563ish cc's.

(sorry, just wante dhim to be able to figure it out on his own, Sam :P )

Don't forget to round off randomly and use "ish's" a lot to show people you really know what you are talking about! That's how I do it!
Fuzzy math = win
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Offline mick7504

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Re: How many CCs does over sized pistons add?
« Reply #3 on: October 29, 2009, 07:35:54 pm »
Here's a crash course in maths!!
I'll try and keep this uncomplicated.
Basically you need to determine the volume of each cylinder. (Displacement = Bore x Stroke)
I'll use the standard 750 Honda measurements for this as an example - (Actually 736cc)
Bore = 61mm
Stroke = 63mm

Bore diameter divided by 2 = radius                                                 eg. 61 divided by 2 = 30.5 (radius)
Multiply the radius by the radius                                                     eg. 30.5 x 30.5 = 930.25 (radius squared)
Multiply radius squared figure (930.25) by the stroke.                         eg. 930.25 x 63 = 58605.75
Multiply 58605.75 by 3.14 (pye)                                                      eg. 58605.75 x 3.14 = 184022.06
Multiply 184022.06 by no. of cylinders (4)                                         eg. 184022.06 x 4 = 736088.24

                                                                     736cc

Pye (3.14) is just a mathematical figure used to calculate this stuff.
Hope this helps
  
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Offline mick7504

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Re: How many CCs does over sized pistons add?
« Reply #4 on: October 29, 2009, 07:37:14 pm »
Quote from: mlinder on October 29, 2009, 07:06:40 pm
:P

Original bore and stroke

58.5 x 50.6 mm

new bore and stroke

59.5 x 50.6

so, 3.14*(29.75^2) * 50.6 (pi r squared x stroke)

= 141 ish
*4 (4 cylinders) = 563ish cc's.

(sorry, just wante dhim to be able to figure it out on his own, Sam :P )

Don't forget to round off randomly and use "ish's" a lot to show people you really know what you are talking about! That's how I do it!
Fuzzy math = win
Sorry mate you beat me to it.  ;D
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Offline Gorms

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Re: How many CCs does over sized pistons add?
« Reply #5 on: October 29, 2009, 07:55:25 pm »
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Offline Flying J

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Re: How many CCs does over sized pistons add?
« Reply #6 on: October 29, 2009, 08:00:59 pm »
Thanks guy, for sorting me out on that. I appreciate you giving me the "fishing pole" and not just handing me a fish. I guess 20 CCs for $250 is not that bad. I may do it just to know i have a fresh set of pistons and cylinder walls.
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Offline mick7504

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Re: How many CCs does over sized pistons add?
« Reply #7 on: October 29, 2009, 08:09:22 pm »
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Offline Steve F

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Re: How many CCs does over sized pistons add?
« Reply #8 on: October 30, 2009, 03:03:43 am »
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Offline mick7504

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Re: How many CCs does over sized pistons add?
« Reply #9 on: October 30, 2009, 03:36:39 am »
Pythagoras was a Greek philosopher who made important developments in mathematics, astronomy, and the theory of music.
The theorem now known as Pythagoras's theorem was known to the Babylonians 1000 years earlier but he may have been the first to prove it although he didn't know a thing about SOHC 750's so that means that we've got one on him!!!

 ;D  ;D  ;D  ;D  ;D  ;D  ;D  ;D  ;D  ;D  ;D  ;D  ;D  ;D  ;D  ;D  ;D  ;D  ;D  ;D  ;D  ;D  ;D  ;D  ;D  ;D  ;D  ;D  ;D  ;D  ;D  ;D
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Offline mystic_1

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Re: How many CCs does over sized pistons add?
« Reply #10 on: October 30, 2009, 05:27:34 am »
Quote from: mlinder on October 29, 2009, 07:06:40 pm
pi r squared



Pi r not squared, Pi r round.  Cakes r squared!

sorry, had to be said  ;) ;D

mystic_1
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Offline Flying J

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Re: How many CCs does over sized pistons add?
« Reply #11 on: October 30, 2009, 07:55:11 am »
Now that i have all my baking options taken care of, is it worth the extra money to do a 1.00 bore? Will it make much of a differance compared to fresh stock rings?
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Offline mystic_1

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Re: How many CCs does over sized pistons add?
« Reply #12 on: October 30, 2009, 08:22:32 am »
Quote from: SamCB750A on October 29, 2009, 06:58:01 pm
It will go up from 544.087cc to 562.847cc, simple :D :D :D

Sam. ;)


You'd be gaining 18.76cc, which is about a 3% increase over stock.  Unless you did other mods I don't think you'll notice it.

mystic_1
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Offline ColinMc

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Re: How many CCs does over sized pistons add?
« Reply #13 on: October 30, 2009, 08:35:18 am »
The biggest thing you'll notice is because of the fresh rings and "fresh" cilinders. A good hone and a new set of rings will give you a similar "seat of the pants" gain. Unless of course you need to bore it out...I wouldn't unless you have to, that way if you DO have to later on because of some damage you have room left to actually bore it out.
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Offline 754

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Re: How many CCs does over sized pistons add?
« Reply #14 on: October 30, 2009, 09:34:03 am »
Weigh the price of bigbore kits versus the pistons you were thinking of.. unless the 1.0s are dirt cheap it aint worth it..
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Offline MCRider

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Re: How many CCs does over sized pistons add?
« Reply #15 on: October 30, 2009, 09:41:12 am »
Quote from: ffjmoore on October 29, 2009, 06:51:12 pm
Im going to do a rebuild to my 550 and was debating on putting in 1.00 oversized rings and pistons. How do i calculate how many CCs that will ad?

I'm not so good at math, pretty good at Google.   :D

http://www.nightrider.com/biketech/calc_displacement.htm
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Offline MCRider

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Re: How many CCs does over sized pistons add?
« Reply #16 on: October 30, 2009, 09:43:32 am »
Quote from: mystic_1 on October 30, 2009, 05:27:34 am
Quote from: mlinder on October 29, 2009, 07:06:40 pm
pi r squared



Pi r not squared, Pi r round.  Cakes r squared!

sorry, had to be said  ;) ;D

mystic_1

Or differentially...

C  M  puppies?

M  R  not puppies.

M  R  puppies

C  M  P?
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Offline Flying J

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Re: How many CCs does over sized pistons add?
« Reply #17 on: October 30, 2009, 09:50:32 am »
the cylinders are the last thing im trying to sort out. I already have ported a spare head and intakes as well as have a 650 cam ready to drop in. All of which should give me some HP gains. Will that light port job and a 650 cam be enough to take advantage of a 1.00 over. The differance in price from stock rings to bigger pistons and rings is about $120.
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Offline lone*X

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Re: How many CCs does over sized pistons add?
« Reply #18 on: October 30, 2009, 01:57:47 pm »
Just curious, seems like a small gain when you factor in that you also will need to pay to get the cylinders line bored to be able to install the oversize pistons.  Are the cylinders scoured?
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Offline Flying J

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Re: How many CCs does over sized pistons add?
« Reply #19 on: October 30, 2009, 04:26:02 pm »
Haven't pulled the engine apart yet. I believe Hondaman said just having the bore re aligned will increase HP. The low budget route is just swapping the ported head and gasket with 650 cam. But i want to weigh my options while i have it apart. I hate to go low budget and then have the lower gasket leak on me or waste the ported head and cam on a engien that will not benefit from it that much. Ill will check my compression before as well.
« Last Edit: October 30, 2009, 04:28:40 pm by ffjmoore »
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Offline the technological J

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Re: How many CCs does over sized pistons add?
« Reply #20 on: October 31, 2009, 12:35:21 pm »
for the sake of discussion whats the biggest bore u can go on a 550? what size pistons and rings would need to be bought?
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