SVThuh

I was wondering if someone here could help me out.. Im looking for the formula for figuring out my dynamic CR from my static CR, and would be willing to show me how it works on a possible setup of mine..

Basically I will be running somewhere around 11.5:1 static CR... That was the easy part.. The hard part for me (im very match challenged) is figuring out what my dynamic CR is going to be with a 355, 6" rods, and a cam with figures around 235/245 @ .050, .600/.585, 110LSA.

I would really appreciate it if someone could do this for me and show me their formula and work for it... I love to learn, but math is one of my weakest areas...

Thanks Guys!!!

rskrause

Do a Google search for "dynamic compression ratio calculator". You will need your cam specs including "advertised" duration (as opposed to duration at 0.050"). You should not have decided on your static CR without taking the cam and DCR into consideration. Though just eyeballing it, it will probably be good.

Rich

Loony

Gimme a call sometime bro, give me the info, and I'll do it for you...

Or just leave me the info on AIM one day...

SVThuh

I was actually hoping to learn the math behind figuring this out... Does anyone have the formula for this???

rskrause

http://www.rose-hulman.edu/Class/Cal...INE/ENGINE.asc

Rich

engineermike

I went through the math/geometry myself. The formula looks something like this:

DCR = ((stroke/2+rod len-((rod len*sin(IVC-asin(stroke/2*sin(180-IVC))/rod len))/sin(180-IVC)))*pi/4*bore^2*2.54^3+ (chamber+dish+gasket volume+deck height volume))/(chamber+dish+gasket volume+deck height volume)

SVThuh

Thanks..

A friend of mine (looney) helped me simplify things, looks like I will be somewheres near 8.5DCR, so I should be fine with the setup im looking at..

Thanks guys.. Oh, I also put some stuff that was sent to me and that I found on the net up on my server just in case someone is interested...

www.socalmuscle.com/~automath