I did do a search without any real clues but would the symtoms be the same as a blown head gasket? I did verify that all cylinders have close to the same compression.
When I start the car, it sometimes will act as if the starter can not turn the engine over but then when I turn the key again it will turn over and start. The car runs perfectly and no white smoke for about one minute. But then the white smoke starts and lots of it. as soon as I start down the road the smoke will go away but the temp goes way up and then bounces up and down. Yes, it looses coolant. The oil looks fine and the compression checks out good. I guess the only way I'm going to know is to tear it down. Any suggestions? I'm concerned because this engine was bored .060 over. I was talked into this before I knew it was not a good idea. One other thought, I did change the heads to aluminum and re-used the ARP head bolts. Maybe I should have bought new?
I would be looking for something other than a crack. Boring .060 over is way too much for a stock block (you already know that). Old or high mileage blocks get very rusty inside the water jacket and as a result the cylinders can become porous with large over-bores. Another very common leak is a blown head gasket but your compression test ruled that out. One other leak point is between the intake and head. This can happen easily if a small ported intake is mated to a large ported head.
Here's a good test to determine if your head gasket or block is the culprit:
1. Remove all spark plugs
2. Obtain a threaded fitting that matches your spark plug thread. Some compression testers will be of this design.
3. Remove the radiator cap
4. Rotate the engine with a wrench until the cylinder is on the compression stroke
5. Thread the fitting into the spark plug hole
6. Connect an air compressor or tire pump to the fitting and add air slowly
7. The air will push the piston back down to the bottom of the stroke and then the cylinder will pressurize
8. If radiator fluid overflows of there's a ton of bubbles, you have a problem with that cylinder.
9. If nothing happens, move on to the next cylinder starting with step 4.
10. If all 8 cylinders pass the test, your leak is before the valves (intake areas)