How to read cylinder compression ?

[makeitfit]

Working on the Black Pearl , again
The old girl has developed some serious blow by once again.
We wererunning high boost back in Jan but steadily reduced it as the combined boost and LPG was producing awesome power but EGTs were getting out of hand.Now down to 1 bar again.
Damage may already done but in the interests of my sanity I'm going to test again.
I've got figures for compresion tests done in Dec 2018 and again in Febuary 2019
They seemed ok and slap bang between min and max according to the manual.
So I may be doing it wrong !
How do you guys suggest I read them please ?

 

[elty001]

I did 3 readings per cylinder and took the average.
All mine where low as the bores where scored and passing oil.

 

[makeitfit]

How many spins of the engine did you do ? Also did you do hot and cold ?
Do you have figures so I can compare please ?

 

[elty001]

I did mine with a warm engine as per the manual.
Off the top of my head they where all around 350 psi,which is low.
Adding a bit of oil to the cylinder increased the pressure indicating worn rings/scored pistons or bores.
I just span the engine over for around 5 seconds until I had a steady reading.
Don't forget to whip the fuel pump fuse out.