Bader-X

iTrader: (2)

what will be the compression for a 6.0 L stock crank with 6.125 rods and flat forged pistons with -2 reliefs with a cometic .040 and 70cc heads?

thanks in advance

dvshk

The cc of your valve reliefs and deck height are needed to work this out

dvshk

Here is something you can work it out with once you have those 2 details above

http://www.wallaceracing.com/cr_test2.php

PREDATOR-Z

~10.67:1

dvshk

How could you possibly come up with that? You don't know his bore size, what cc the valve reliefs are or how far out the piston crown is out/down the bore

GA95DCMSS

iTrader: (13)

dvshk,

Bore Size for 6.0L Iron Block (all) =4.0in
Valve Reliefs are stated in the first post.
Using Stock figures for what isn't stated, I came up with ~10.63:1
My math may def be off a little.
Seeing as we don't know how far his piston it out of the hole at TDC,I just used some "stock", figures but Pred is def in the ballpark.

PREDATOR-Z

That is why I used the "~" sign, meaning aproximate

GA95DCMSS

iTrader: (13)

I know. Obviously dvshk can't read between the lines lol.

dvshk

Well done mate!

PREDATOR-Z i apologize as i did not see the - in front of the 2. I thought he was stating he had 2 valve reliefs

Bader-X

iTrader: (2)

thanks for the answers and sorry the bore is 4.030 and 0 deck hight ... it`s in the good zone for N/A and a little spray ^_^

405HP_Z06

iTrader: (11)

I don't get anywhere near 10.67. With a 4.00" bore I calculate 10.2 and with a 4.030" bore it's the following:

PREDATOR-Z

Well by adjusting deck height, I get 10.42:1

Sooo OP, you are in the ballpark of 10.35 >>>10.45:1, because while calcs are accurate in counting, it is the data entries that are not spot on. (unless you actualy measure all of them and input actual data correctly)
My 370 was .01 out of whole so that is what I had used in deck height entry for the 10.6 calc/

405HP_Z06

iTrader: (11)

I don't know what math you learned, but based on the information provided by the OP, his SCR is 10.34 not 10.45.

If you would drop your ego glasses, you would see that......sheeesh.

dvshk

Using the link that i posted which is a very basic comp calculator it does not take into account gasket bore size, it does come out @ 10.42:1 on this calculator. The bloke is only after a rough estimate! You can't possibly give him a exact cr as you have not personally measured a thing

405HP_Z06

iTrader: (11)

okay, lemming. Whatever...... argue with tree, it can obviously calculate better. Your not taking ALL aspects into consideration. Why don't you go do some homework.

dvshk

Hmm i wonder who is wearing those ego glasses? (lemming)

PREDATOR-Z

Yeah, you are correct, I forgot that you are actualy measuring all the numbers on the engine itself, what was I thinking, your calculation must be spot on

GA95DCMSS

iTrader: (13)

Thats the same thing I did Pred. He said nothing about piston popup, and I assumed it was going to be somewhere close to stock tolerances (.005-.008 but I've seen as much as .010) and I used this calc because i couldn't find my excel sheet. Am I missing something?
http://www.csgnetwork.com/compcalc.html

PREDATOR-Z

Nah! not a thing, but 405hpZO6 got too much jalapenos on his burrito today

Bader-X

iTrader: (2)

ARGUE WITH TREE !!! HAHAHAHAHAHAHA *cheeks hurting from laughing* (face cheeks )