66 Dart GT HT Whatsitgonnabe?
Big day today. I followed - from memory - @krazykuda s excellent thread on compression calculation.
I only did one chamber on both block and head. Too lazy to be more thorough.
These are the numbers:
Head volume (measured): 70 cc
Cylinder volume (measured): 22.5 cc
distance in hole*: 2 mm
Gasket hole diameter: 104.6 mm
Gasket thickness: 0.98 mm
Cylinder diameter: 102.3 mm
Stroke**: 90.932 mm
Remove volume from piston in the hole: −16.4 cc
Actual volume in cylinder @ TDC:
Gasket hole volume: 8.4 cc
Total chamber volume @ TDC 84.5 cc
Total chamber volume @ BDC 831.9 cc
Compression ratio 9.85 :1
Very close to 10:1 which, according to local expertise, is the limit for Swedish unleaded pump gas @ 95 octane.
I'm happy with this! It's a lot better than I thought. Now all I need to do is GET THE THING RUNNING!!!
* With the domed KB pistons, I needed to cc the cylinder with the piston 2 mm below TDC. This means I got a volume LARGER than actual at TDC.
** Normal 360 stroke of 3.58", not measured.
Big day today. I followed - from memory - @krazykuda s excellent thread on compression calculation.
I only did one chamber on both block and head. Too lazy to be more thorough.
These are the numbers:
Head volume (measured): 70 cc
Cylinder volume (measured): 22.5 cc
distance in hole*: 2 mm
Gasket hole diameter: 104.6 mm
Gasket thickness: 0.98 mm
Cylinder diameter: 102.3 mm
Stroke**: 90.932 mm
Remove volume from piston in the hole: −16.4 cc
Actual volume in cylinder @ TDC:
Gasket hole volume: 8.4 cc
Total chamber volume @ TDC 84.5 cc
Total chamber volume @ BDC 831.9 cc
Compression ratio 9.85 :1
Very close to 10:1 which, according to local expertise, is the limit for Swedish unleaded pump gas @ 95 octane.
I'm happy with this! It's a lot better than I thought. Now all I need to do is GET THE THING RUNNING!!!
* With the domed KB pistons, I needed to cc the cylinder with the piston 2 mm below TDC. This means I got a volume LARGER than actual at TDC.
** Normal 360 stroke of 3.58", not measured.