When it was new it had 150 PSI. per cylinder
If it's in good shape, Then all cylinders should read about 150 LBS. Less is okay as long as all of them have no more then 10 LBS. difference between them. If the compression is less then 120 LBS. then the engine has valve or pistion ring problems.
NO. That is to low. If it is a good tight engine it should have at least 150 PSI per cylinder. You can not have any more of difference then 15 LBS per cylinder are the engine will idle rough.
You will have to do a compression test yourself to know that. A engine that is in good shape should have at least 150 LBS. per cylinder. There can not be more then 20 LBS. difference in any cylinders. It has to have at least 100 LBS. for the cylinder to fire at an Idle.
To determine the compression stroke on a 350 Chevy engine, first, remove the spark plug from the cylinder you want to check. Then use a compression gauge and crank the engine over by hand or using a starter until you see the gauge reading stop climbing. This indicates the compression stroke where the air-fuel mixture is being compressed in the cylinder.
Tire psi? Engine compression psi? Radiator cap psi? Engine oil pressure psi?
NO. It should start at about 150 LBS. PER cylinder. And you can't have anymore then a 15 Lb. difference in any cylinder, are the engine will idle rough.
It varies from one engine to the next but, what you want to see is that all the cylinders compression readings are within 10% of each other.
The year and engine size would help but you may have a bent valve or bent pushrod for # 4 cylinder if that is the only cylinder that has 0 for compression.
That engine FRESH / NEW should have 150 LBS. compression per cylinder. If you have more then 20 LBS. difference in any cylinder then it is not in good shape and a good VALVE JOB is probley in the furture.
The lack of compression in one cylinder of a Chevy 355 engine could be caused by a number of issues such as a leaking valve, a blown head gasket, a cracked piston, or improper sealing of the piston rings. It is recommended to perform a compression test and further diagnostic tests to identify the exact cause of the low compression in that cylinder.
150-160 PSI