John,
If you want to drive up to Arlington, we can measure the dish and diameter of the top ring land. I don't remember where you were located...
I have an excel spreadsheet at home that will make the number crunching a ton easier, and it accounts for the volume above the top ring...
I didn't bother with dynamic compression though...
jason
If you want to drive up to Arlington, we can measure the dish and diameter of the top ring land. I don't remember where you were located...
I have an excel spreadsheet at home that will make the number crunching a ton easier, and it accounts for the volume above the top ring...
I didn't bother with dynamic compression though...
jason
The main ingredients of a static compression ratio are very simple:
- Cylinder swept volume = Bore(2)*stroke*.7854
- Clearance volume = .7854*(piston top from engine deck height)*Bore(2)
- Piston dome(+), dish(-), or flat (0) = cubic centimeters
- Head-gasket volume (gasket height*.7854*Bore(2)
- Cylinder head chamber volume = cubic centimeters
The ring land volume creates a very minimal change by accounting for the piston to wall distance and the distance from the top ring to the top of the piston volume.
Atleast it is easier to quantify better than blow-by and other variables that change at every degree of crank rotation.
FYI, .7854 is a rounded off number for PI/4. Relatively speaking, it is the area of a circle inside a square.
- Cylinder swept volume = Bore(2)*stroke*.7854
- Clearance volume = .7854*(piston top from engine deck height)*Bore(2)
- Piston dome(+), dish(-), or flat (0) = cubic centimeters
- Head-gasket volume (gasket height*.7854*Bore(2)
- Cylinder head chamber volume = cubic centimeters
The ring land volume creates a very minimal change by accounting for the piston to wall distance and the distance from the top ring to the top of the piston volume.
Atleast it is easier to quantify better than blow-by and other variables that change at every degree of crank rotation.
FYI, .7854 is a rounded off number for PI/4. Relatively speaking, it is the area of a circle inside a square.
Yeah, I thought you had stuff apart...
Do you remember who you purchased the pistons from?
They may still have a record/invoice of what you picked up
I suppose you could cc the piston by pulling the head....
Gets trickier if the piston doesn't stick out of the hole though