volvo b230 working out compression

[bmw2101]

Ive the volvo b230 engine, I'm sorting out the head for it now. Its a 531, standard chambers, little porting, and standard valves. Its going on a b230a engine so it has slightly dished pistons.

cam  i have gone with is this spec

Opening Duration 300 degrees
cam lift 12.9mm
Lobe center line angle 108 degrees
TDC lifting about 4.5mm.
Valve clearance 0.35 mm

engine is

2.32 Litre (2,320 cc), Bore 96mm Stroke 80 mm

I understand there is static compression, and there is the real compression. So the static maybe like 13:1 while with the cam opening, itll be like 10:1

How can i work out what this cam will do, and what do i want the compression to be? I'm a bit lost and need a few pointers please!

I know the head will need skimming a fair bit, valves are miles away from the pistons as they open flat to the piston, i ve heard of people taking 2.5mm from these heads.

thanks

[slater]

Well this will help you calculate it. Dynamic compression has alot of factors but basically the longer the cam duration the less dynamic compression you will really get.

www.gofastmath.com/Compression-Ratio-Calculators/Static-And-Dynamic-Compression-Ratio-Calculator

If they question is more about 'what compression ratio can I get away with' theres a whole other can of worms to open there. Everything from fuel, ignition, chamber design, cooling efficiency. It's not really possible to calculate. You are probably best finding other people who have built simlar engines and asking them. As a ballpark I'd say 11:1 static might be good to aim for. The cam is fairly long but I don't really know much else about the engine.

[bmw2101]

thanks, how do i work out the ivc? i just cant work out how to do it !

thanks!