Super Jet 701 bored 1 over = ?

[logan holder]

I just got my 61x cylinders bored one over by DASA and was wondering what displacement it might be at/around?
just curious. :scratchchin:

 

[r6487]

if you look at someplace like wiseco pistons for 701 piston listings these are listed: 701---710---718---727---736 as the cc displacement for oversizes. if by 1 over you mean bored over 1mm that would be 2nd oversize at 718cc, if you mean bored over to 1st oversize (0.5mm) that would be 710cc--hard to tell which you one you are describing

 

[Matt_E]

It depends what 1 over is. 701 stock sized pistons go with an 81.0mm bore. The first oversize is +0.25mm or 81.25mm.

To calculate displacement, remember that you have two cylinders. So 2 x volume of a cylinder.
Volume of a cylinder: area of circle * height = Pi * (radius)^2 * stroke

Displacement = (bore size / 20) * (bore size / 20) * 3.1416 * 6.8 * 2
At 81.25mm that's 705cc
At 81.50mm that's 709cc
At 82.00mm that's 718cc

 

[raytherace]

http://www.ducatitech.com/info/bore.html

 

[Matt_E]

http://www.ducatitech.com/info/bore.html

Unfortunately that size covers bores only in increments of 2.0mm, at even numbers. Useless for SJ motors for the most part.
The strokes only go up to 71.5mm.

 

[eeerieski]

http://www.x-h2o.com/threads/5136-Yamaha-62T-61X-Displacement-vs-Bore-Stroke-Combinations
my 61x is 81.25 so interpolate to get 705cc
/thread

 

[raytherace]

Unfortunately that size covers bores only in increments of 2.0mm, at even numbers. Useless for SJ motors for the most part.
The strokes only go up to 71.5mm.

Matt you talk about the displacement finder, but take the free form calculator just under, but yeah its goes only at one decimal after the period.

 

[Matt_E]

Sorry, did not see that.

 

[logan holder]

Yes its bored over 1mm, not .25mm. Sorry for the unclarification.
thanks guys really helpful information :smile: