ok so i checked on cspeedracing.com, it says my compression is 12.2:1....
arias pistons website say with stock head 14.0:1....

setup:

arias 13.5:1cr
85mm bore
89mm stroke.
.030 cometic HG


which one is it? 14 or 12? if you guys need more info on the engine let me know!!

 

bump someone here has to know

 

what cyl. head are you running? Is it spot faced?

what is the dome displacement of the pistons?

compression height?

Is it a B18C? Dood.... too many things you left out....

 

-What head is being used? Moreso, what are the displacements of the chambers (CC)
-Are you going to 0 deck the motor?
-Are you using stock compression heights and rod lengths?(i would assume yes)

On those ntoes, Im going to assume from the 13.5:1 and 14:1 you mentioned, that you have 7.4cc pistons (based off their catalog).

with:
-89 stroke
-85 bore
-7.4cc piston dome
-0 deck
-stock b16 head (42.7cc)
you will have 13.75:1

with:
-89 stroke
-85 bore
-7.4cc piston dome
-0 deck
-stock gsr head (41.6cc)
you will have 14.11:1

If you need more help, just post

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RPRacing &raquo;</TD></TR><TR><TD CLASS="quote">-What head is being used? Moreso, what are the displacements of the chambers (CC)
-Are you going to 0 deck the motor?
-Are you using stock compression heights and rod lengths?(i would assume yes)

On those ntoes, Im going to assume from the 13.5:1 and 14:1 you mentioned, that you have 7.4cc pistons (based off their catalog).

with:
-89 stroke
-85 bore
-7.4cc piston dome
-0 deck
-stock b16 head (42.7cc)
you will have 13.75:1

with:
-89 stroke
-85 bore
-7.4cc piston dome
-0 deck
-stock gsr head (41.6cc)
you will have 14.11:1

If you need more help, just post</TD></TR></TABLE>


you are good lol 7cc dome size, rod length is not stock they are custom cunningham rods, 6.3777", chamber volume 43cc, below deck 0.0000", and its with a gsr head, head cc says 41.6. im reading this off the arias piston spec sheet i got for the engine. oh and there is also a 1" deckplate on there.

 

bump for me

 

yah dude it checks in at 13.51 with a 7cc dome. and those dimentions. deck heigth and rod length have nothing to do with it. how far the piston sits below the deck does. I used .010 below deck, its a good average. but u should check to be exact.

 

hmmmm 13.5 sounds better than the 14.1:1....it says on the spec sheet it is 0.0000 below deck but i will get it measured just to make 100% on that.