The increased lift will help, though with only a 0.030" extra, I dont think it would be worth the money.
The duration figures were taken at a lift of about 0.050" or so. This is ok for finding the cams, fully open point, to set the lobe center, when setting the cam timing. But it does not help in finding the degress that the valve is starting to open or close. These are the figures that Subaru are quoting, to give the 236 degs duration for the inlet. These figures are measured at a very small lift to give a better idea of the opening and closing points.
The valve timing figures quoted by Subaru are,
inlet opens 2 degs BTDC closes 54 degs ABDC. duration 236degs
exhaust opens 55 degs BBDC closes 9 degs ATDC. duration 244.
To get the engine to operate at higher RPMs the duration is extended, to get the air in, in a shorter time. But as I said the Inerta system provides the extra pressure, due to the 4 degs that one inlet valve is closed, before the next inlet valve opens.
Without this 4degs of pressure build up, there is no extra pressure from the Inerta system and in consquence no extra torque below 4000rpm. If the engine is running an auto box, you would need a torque converter with a stall point of about 3500rpm to get it off the line. If it was running a manual, it would need a 6 speed to spread the torque down, to lower road speed.
To retain this low end torque, the duration should be left the same. The valve fully open point of the timing, could be retarded to move the torque point up to a higher rpm, with out loosing the Inerta torque. More lift will increse the torque through the rpm range.
As for the claims that he is making, He's pissen in the wind. Did the cam grinder, take in to account the inlet system that this engine has? or is this his, "off the hook 1/4 race cam grind"
Harvey.
