Engine Check for Oil Pressure and Compression

The 425 Buick Nail head from a 1966 Buick Electra 225 last ran in 2008 but it has been stored inside and it ran well then.

In preparation for install into the Gasser I power washed the engine and transmission and removed the distributor and used a tool to drive the oil pump.  The oil pressure was at 40 PSI so I changed the oil and filter and rechecked it (OK) and ran the pump for a few minutes.

I removed all of the spark plugs and put a few squirts of Marvel Mystery Oil in each cylinder and let it soak a few days.  I put a few more squirts in and rotated the engine with a breaker bar on the balancer and the engine turned over easily.

I checked the compression of each cylinder with my tester and ran the oil pump before I did each cylinder in order.   The compression varied a little between a high of 180 PSI on 3 cylinders, 175 PSI on 4 others and a low if 160 PSI on 1 cylinder ( 88 % of the high reading).  I will recheck later and see if there is a ring or valve issue when I pull the valve covers.


I plan to see if the engine will start after I check and reinstall the Carter AFB carburetor and new electronic distributor and coil.


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