Compression pressures

[dickie65]

Hi Zeto,
I have always done compression tests with the engine running when possible.
It gives me a more accurate balance across the engine.
Being a pressure fed 65 its nigh on impossible to crank the thing by hand ! as soon as the oil pressure rises it pushes the handle out of engagement.
I do not want to overheat the starter motor with too much cranking either.
I will charge the battery up and take all the plugs out and give it a go on the starter motor tommorow though.

[dickie65]

Hi Folks,
The results are in.
Engine was run to warm it but not hot enough to burn fingers on plug tops.
All tests were done running a 6v starter on 12 volts as the car has been 12 volts for many years.
Hand throttle wide open.
No 1 = 130 psi 9 Bar
No 2 = 130 psi 9 Bar
No 3 = 130 psi 9 Bar
No 4 = 100 psi 7 Bar I put oil into this cylinder and tried again with the same result.
So I have a poorly sealing valve on number 4
I will not do anything about this yet as the engine still pulls well although I will check the valve clearances.