So you post this and when people give you good advice you act like a know-it-all? Problem is you dont know and it shows.

TTT?

-Dustin-

 

Lloyd gave you the best advice here. That cam needs compression and it sounds like some parts are mis-matched.

 

a large duration cam means that the valves are open for a long time and this obviously allows more air to come ina dn out of the cylinders. For every degree of crank rotation that the valves are open, that is 1 more degree of crank rotation that you are NOT trapping cylinder pressure 1 more degree of crank rotation that the piston is NOT pushing down on the crankshaft.

If the biggest cam made the most power, we would all be running cams with 720 duration and the valves would never be closed.

Just because you have alot of air coming in the cylinder on intake stroke and going out the cylinder on exhaust stroke, does not mean that you are making power. Large cams cause cylinder pressure to be low, you have alot of overlap (same contaminated air gioing in/out of cylinders and killing intake charge/exhaust pulse) and you stop pushing down on the piston sooner. End result is LESS power.

You need LOTS of compression and spin LOTS of RPM to make that cam work OK and you still need to keep it in the 5500-7000 RPM window since power will dramaticallty fall off below that.

A smaller cam would amke alot more power below 5500 RPN and still amke a lil more power from 5500-7000 RPM.

Lloyd

 

+1 This is what I was trying to tell him but you say it much better. Lloyd you are the MAN plain and simple. I will be getting ahold of you soon.