Series V Engine troubles

[fred1725]

My 1725 had been running ok but then
started to run on 3 cylinders and then come
back to 4and back to 3.
I checked fuel, ok, replaced ign wires. rotor and cap
and have spark to all 4.
So on to compression check, 150, 150, 150, 75.
My observation is must be valves or rings.
Is there a way to find out without taking the head off?
If it is a stuck valve can it be lubed externally?
All opinions welcome.

Thanks
Fred

 

[RootesRacer]

If you put oil in the cyl and the pressure goes to normal it is rings.
If not its a valve or blown head gasket.

 

[fred1725]

Thanks
I will try that tomorrow.

Fred