starfire4 writes, "water (and most liquids) is generally considered incompressible."
For trivia, if compressed enough, water can be turned to ice and will expand by 10%. Ice is often made by young students during lab using a simple piston, cylinder and heavy hammer.
Although extreme pressure is require, water can be compressed as much as 5%. Within an engine, .01% to .03% compression would not be all this uncommon, even if for brief moments of time.
However, in its gaseous state, water can be compressed by thousands of percent. This is why air compressors need to be drained of water on a periodic basis. Part of this is condensation inside a tank although the compressed air is warmed or even heated by the compression process. Part of this is simply squeezing moisture out of air through compression.
Steam is highly compressible. This term "compressible" is very relative to context of function. You are thinking within a context function of only liquid water.
starfire4 adds, "...if adding steam holes fixes the problem, quick or otherwise, then it's fixed."
You are assuming any given fix is a correct fix. If this could be true, we would not make so many mistakes when working on our vehicles -- best laid plans of mice and men.
A quote for you,
"...engineers at Fel-Pro have developed a solution to solve this overheating problem with some 400 engines. The procedure is designed to place more coolant around the adjacent exhaust ports to prevent creation of steam that hurts the cooling process...."
- John Lingenfelter, "John Lingenfelter on Modifying SB Chevy Engines", 1996
"...prevent creation of steam that hurts the cooling process...."
The mere presence of added steam holes in a 400 small block directly points to an overheating problem. This steam should not be generated in the first place; there should be no need for steam holes, if an engine is properly designed.
Billyray
