30-11-2019, 11:59 PM
I wrote in September 2018 and I quote-
The standard Compression Ratios seem to be
1923-1933 4.8 (or 4.9) to 1
1933-1936 5.2 ? to 1
1936- 1939 6.0 (or 6.2?) to 1
I understand that Compression Pressures are between 17 and 20 times the Compression Ratio in a good engine giving :
4.8 to 1 = 80 to 96 psi
5.2 to 1 = 88 to 104 psi
6.0 to 1 = 102 to 120 psi
I get around 100 psi from the standard early head and 110 psi from the 1936 head with dry hand cranking and throttle open.
As suggested all cylinders should be within around 3-5 psi of each other .
The standard Compression Ratios seem to be
1923-1933 4.8 (or 4.9) to 1
1933-1936 5.2 ? to 1
1936- 1939 6.0 (or 6.2?) to 1
I understand that Compression Pressures are between 17 and 20 times the Compression Ratio in a good engine giving :
4.8 to 1 = 80 to 96 psi
5.2 to 1 = 88 to 104 psi
6.0 to 1 = 102 to 120 psi
I get around 100 psi from the standard early head and 110 psi from the 1936 head with dry hand cranking and throttle open.
As suggested all cylinders should be within around 3-5 psi of each other .