4age 16v and 20v piston dome volumes
Posted: Fri Dec 14, 2012 7:46 am
Here are my OEM piston dome volumes. I calculated these from specs i found on the internet and also from other peoples build threads.
Advertised compression ratios
BP=9.4:1 (euro)BP=10.1:1 SP=10.3:1 ST=10.5 BT=11.1:1
advertised head CC
16v=36cc 20v ST=34.5 20v BT= 37.8cc
Engine-----------OEM CR-----headCC--------Piston heigth-------------piston dome:
4agze (BP)---------8:1---------36cc---------------30mm----------------------- -11.9
4agze (SP)-------8.9:1--------36cc----------------30mm---------------------- -5.45
4age (BP)--------9.4:1--------36cc----------------30mm----------------------- -2.5
4age (euro)----10.1:1--------36cc----------------30mm----------------------- 1.15
4age (SP)-------10.3:1--------36cc---------------30mm----------------------- 2.1
4age (ST)-------10.5:1--------34.5cc ------------30.5mm--------------------- -1.1
4age (BT)-------11.1:1--------37.8cc ------------30.5mm--------------------- 4.7
looking at old post i found that the ST has .2" taller comp heigth. so the compression heigth is 30mm for the 16v and 30.5 for the 20v (this info from dr.occa from a previous post) the previous chamber heigth number 1.171"(29.7mm) is from ares and is actually what ares uses as there chamber heigth.
the BT comp heigth is at 1.202 (30.5mm) provided by gaijin_rokurunner...thanks gaijin
thanks sam_Q for posting your bt20v chamber volumes and oldskewltoy for the 16v chamber volumes
I think these are as acurate as i can get with out actually measuring the pistons. now you can figure out what compression you want and chose the oem part that gets you there. You can test dynamic compression with a more accurate numbers to choose the right cam for your setup
I am currently working on getting the numbers and volumes of the 4ac engine but i dont know the compression chamber volume to make an accurate calculation
Advertised compression ratios
BP=9.4:1 (euro)BP=10.1:1 SP=10.3:1 ST=10.5 BT=11.1:1
advertised head CC
16v=36cc 20v ST=34.5 20v BT= 37.8cc
Engine-----------OEM CR-----headCC--------Piston heigth-------------piston dome:
4agze (BP)---------8:1---------36cc---------------30mm----------------------- -11.9
4agze (SP)-------8.9:1--------36cc----------------30mm---------------------- -5.45
4age (BP)--------9.4:1--------36cc----------------30mm----------------------- -2.5
4age (euro)----10.1:1--------36cc----------------30mm----------------------- 1.15
4age (SP)-------10.3:1--------36cc---------------30mm----------------------- 2.1
4age (ST)-------10.5:1--------34.5cc ------------30.5mm--------------------- -1.1
4age (BT)-------11.1:1--------37.8cc ------------30.5mm--------------------- 4.7
looking at old post i found that the ST has .2" taller comp heigth. so the compression heigth is 30mm for the 16v and 30.5 for the 20v (this info from dr.occa from a previous post) the previous chamber heigth number 1.171"(29.7mm) is from ares and is actually what ares uses as there chamber heigth.
the BT comp heigth is at 1.202 (30.5mm) provided by gaijin_rokurunner...thanks gaijin
thanks sam_Q for posting your bt20v chamber volumes and oldskewltoy for the 16v chamber volumes
I think these are as acurate as i can get with out actually measuring the pistons. now you can figure out what compression you want and chose the oem part that gets you there. You can test dynamic compression with a more accurate numbers to choose the right cam for your setup
I am currently working on getting the numbers and volumes of the 4ac engine but i dont know the compression chamber volume to make an accurate calculation
