sounds complicated thanks.

 

If you are running a 4mm stroker w/ .060" over, then you are 390.67 ccs. (Just noticed you had that listed in your signature.)

 

how do you know how to do all that??

 

He paid attention in math class...... [img]i/expressions/face-icon-small-happy.gif[/img]

 

Here it is as simple as it can be. Just use this formula.

radius x radius x stroke x PI x number of cylinders

radius = diameter / 2
Stock bore (diameter) is 64 mm, since .060" over bore = 1.5 mm, your bore is now 65.5 mm
65.5 mm / 10 = 6.55 cm (10mm = 1 cm, hence the reason dividing by 10)
6.55 diameter divided by 2 = 3.275 cm radius
so lets start filling in the formula: 3.275 x 3.275 x stroke x PI x number of cylinders
stock stroke is 54 mm, yours is +4 = 58 mm = 5.8 cm
so the formula is: 3.275 x 3.275 x 5.8 x PI x number of cylinders
PI = 3.14 and you have 2 cylinders, so let's finish putting the numbers in the formula:
3.275 x 3.275 x 5.8 x 3.14 x 2 = this is the number of ccs that your engine is displacing.

Hope that makes easy for you.

Daren

 

[img]i/expressions/face-icon-small-shocked.gif[/img]

 

well, look at the $120 this way, would pay pay $120 for an extra 10 hp in your quad? yes. hell, people pay that for their car, that allready has 200+hp. If you have done everything to your ability, then take it to the dyno, to squeeze every little bit of potential out of it. If they guarantee 10hp, their more than likely analysing the exaust gasses.

 

Results of the dyno runs? Did you gain more HP like the claim?

 

what is a bone stock bore with a 4mm stroker crank?

 

372.9 = stock bore and 4 mm stroker