Bigger Cam = Higher Compression?

[tx01z]

When you install a bigger cam, I assume the cylinder pressure increases, thus the cylinder temperature increases, thus the possibly of having to lower the stock timing to prevent detonation, correct?

[RomansDesigns]

We usually talk about compression ratio's and use the static compression as the benchmark. Dynamic Compression is what the engine sees and is calculated by when the exhaust valve closes. Here is a link that helps you calculate your dynamic compression ratio..
http://www.kb-silvolite.com/calc.php?action=comp
When you put a in a larger cam, the exhaust valve closes later and you drop your dynamic compression ratio. Usually you have to run more timing at lower rpm's because the VE is lower and you need more timing. I have found that a big cam will require more timing on top end too. Even though VE's are higher at high rpm's and loads, the engine keeps making more power until just before detonation.
Mark

[WS6FirebirdTA00]

Dynamic compression has to deal with the intake valve closing angle, not the exhaust. The bigger the cam, the less advance, the lower your DCR is going to be.

The engine can make peak power well before getting knock. Sometimes, you may lose a few hp with too much timing, without seeing knock.

Now with a cam and high rpms, you get better cyl filling, but that does not mean you will have to lower the timing. It all depends on how well the flame front travels through the charge.