Dude,
I will make it easier for you to give us an estimate of the actual power difference between a standard hydraulic and a hydraulic roller cam. I have picked a standard catalog mid-range hydraulic roller from the Comp Cams catalog – the XR288H It has 236 degrees intake duration with .520 lift (.347 lobe lift), and the lobe is at 106. The exhaust is 242 degrees with .540 (.360 lobe lift) and is at 114 degrees.
I have selected comparable duration lobes from the Bullet Racing catalog and can have a cam made for $150. This standard hydraulic cam will have the lobes in the same exact positions – 106-114. The intake is 235 with .507 lift (.338 lobe lift), and the exhaust is 242 with .510 lift (.340 lobe lift). They do not have a 236 lobe with decent lift, so I chose the 235 lobe. If you prefer different lobe positions, change them but make both cams the same.
Assume a 462 engine with stock 87 cc E-heads with either an RPM or T-II and appropriate carb (but same on both setups). How much power difference in torque and HP will there be at 3000 RPM, 4000 RPM, 5000 RPM, and 6000 RPM (assuming the h rollers can make it to 6000 RPM)? And assume the Rhoads lifters are used on the standard cam to assure it will easily run to 6000!
And after making that estimate, assume the rocker ratio was changed from 1.5 to 1.65 on the standard cam, making the lift .558 and .561. How do the two cams compare then? Note the same valve springs and related parts could be used with no other changes in cost or effort.
As an engine builder, I suspect you would know this in order to be able to recommend the best power increase for the dollar spent. Thanks.
Jim Hand
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