The correct displacement for a 95mm jug is 666cc.

Here is an online displacement calculator.

http://www.ajdesigner.com/fl_engine_displacement/engine_displacement.php

Point taken about the other factors such as timing and chain tension, that alone makes me not want to go this route...

But to beat a dead horse, I understand that would simply using the equation for cr

{[l•(πr²)]÷cr} : {l•(πr²)}

making it:

{[94•(π47²)]÷8.5} = 76745mm² or 76.75cc

I realize now I asked the wrong question, not what the displacement of the combustion chamber is, but rather the differential equation on reducing the chamber from the bottom up.
Which I am getting the idea isn't known outside of Suzuki engineering.

For if one simply uses the equation of a hemisphere the calculation is off as one can see below, the chamber isn't nearly a true partial hemisphere.

(disclaimer not my pic, sorry if its yours)


I just figured someone had to know becuase if the ratio out there for the wiseco domed piston of 10.5 is accurate, then the actual differential equation for the chamber has to be known, as well as the deck height (ie the height within the cylinder that TDC extends to)
I'm just not aware of another way for this number to be accurate without someone using the proper calculation, or doing the liquid measurement.
Thus must I then conclude that the ratio stated for the domed piston of is just a ballpark estimate as well?

here is a interesting article that address the problem:
http://www.chevyhiperformance.com/techarticles/46778_engine_compression_guide/

Now we can measure the change in piston height and come up with a reasonable estimate.

If someone can measure the distance from the top of the piston to the top of the wrist pin on both pistons along with the width of the high portion of the wiseco piston and the step from the high to low portions.

just ran across this quote from mr LANCER in another post:

"I just went back and did some calculations with the new piston.
The raised area on the piston displaces 8.5cc's of the combustion chamber volume which raises the compression 1.4 pts up to 9.9:1, and the additional 3 mm bore increases cyl vol which adds another 0.6 pts, bringing the new total compression ratio to 10.5:1"

But there again lies the problem, with all due respect, hearsay, I haven't seen anything published on the displacement of this domed piston.

But for the sake of argument lets plug his number in to the equation for the 95mm bore.
Starting from stock chamber volume calculated above.

{[94•(π47²)]÷8.5} = 76745mm² or 76.75cc

then new chamber volume:
76.75 - 8.5 = 68.25

toss that in with the new bore 666.29 : 68.25 = 9.76

So for those of us going with the 95mm piston, i think we should well consider the number is more likely 9.75 or so, and not the 10.5 that some are advertising.

And while id like to know where that dome displacement number came from, it seems reasonable and i think i can live with it as is...

That said, i just got my cylinder off and prepping to send out to boretech.

Dave wrote on 12/02/13 at 05:07:03:



Just was confused as some stated the 95 bore was the same as the 97.

This was the only thread i found, until this morning.
This thread sort of answers the question already:
http://suzukisavage.com/cgi-bin/YaBB.pl?num=1175481076/0
they estimate 9.5 for the 95mm, though again with with no data to back it up.

Maybe compression ratios should get a thread in the Tech Specs section.

As for doing the measure myself, i haven't committed to doing any valve work yet, to take an effective measurement it would likely require lapping the valves to help reduce leaking.
Also i don't have the graduated tooling required, and dont care to purchase them.