Hey guys, cookin' up another project. Thru my readings I've found that duration and the intake valve closing point determines where the engine makes power and LSA focuses that power. But what about the total time the valves are closed? That's all time that the engine is building pressure, so logic would lead me to conclude that more is better............

 

It's really every event that determines power level, power characteristics, and idle manners.

Intake open, intake close, exhaust open, and exhaust close. Duration, LSA, and ICL are all just a function of those events.

 

yep. try not to give each spec a specific duty to perform. they all work together.

 

Thanks guys- that's liberating. what I've cooked up so far with intake valve closing at 51.5* should yield 143 lbs cranking compression at 5,000 ft.............

 

Not sure what your engine is but that's a pretty late close unless your moving allot of air.

 

I thought it was pretty early as Comp Cams 259 closes the intake valve at 59* after bottom................

 

I bet they are listing .006 numbers

If so that's a different story.

 

Yes sir, measured at .006..........

 

Additional lift has to count for something.............

 

It does within reason, depends how much you are talking. With stock heads no sense going crazy.