How healthy is this rebuilt motor?

[Dibbons]

This is a question regarding matching numbers 318 two barrel motor in a 1972 Satellite Sebring Plus that has a tag identifiying it as having been rebuilt (probably in 1978) at Art Schedler's Engine Rebuilding and Supply, Fresno, California: Rods 020 Mains 030 Cyl 0 0 Date 7 8. Compression readings were taken at the normal 5 cranking spins and then 10 cranking spins. Engine was warm but throttle was closed during testing. The higher numbers indicate readings after ten spins and the lower numbers indicate readings after five spins.

#1 85-120 #2 90-120
#3 80-120 #4 80-125
#5 80-125 #6 85-120
#7 50-110 #8 60-110

Engine had been stored for 5 years and all gaskets were changed (except rear main seal) before testing. Timing chain, water pump, and fuel pump are new. Cylinder heads, rings, and bearings were not renewed for test. The engine idles very smoothly but is a little hard to start when cold. When warm, it starts instantly. My number one question is, why do you think the readings take 10 spins to max out? Thank you.

 

[coloradodave]

First, the choke and throttle should be open. You crank the motor until the highest number is reached. Whether it takes 5, 10, or more before the needle stops rising is inconsequential. If numbers are within about 10% of each other, you're fine.