My first post and its a tech question. I am working on a 1920 7 passenger. Just got the motor turning over. (Turning good) The problem so far is that the two front and the two rear cylinders have zero compression. Is there a way to figure out if its stuck valves or something with the crank. Just seems odd that the cylinders with no compression are working off of the same journal on the crank. Any ideas will be muchly appreciated. Thanks Randy Allgood
Get the cylinder to TDC and apply air to the plug hole. You will hear the air in the exhaust or the intake if those valves are stuck.
Zero compression would hopefully be stuck valves. Pull the valve covers and have a look. Its not that hard to do on a 70. You may also now have bent pushrods. If the pushrods bend they may fall out if/when the engine starts which leads to a lifter falling out which leads to zero oil pressure.