Which cam will make more power on a modded 350TPI engine:


Camshaft #1:
* Advertised duration: 276 intake/284 exhaust
* Duration at .050 in.: 214 intake/222 exhaust
* Gross valve lift: .488 in. intake/.509 in. exhaust
* Lobe separation: 112 degrees


Camshaft #2:
* Advertised duration: 264 intake/269 exhaust
* Duration at .050 in.: 212 intake/218 exhaust
* Gross valve lift: .488 in. intake/.495 in. exhaust
* Lobe separation: 112 degrees

Notice the large difference in advertised duration compared to the .050 duration. I'd like more power in the mid-upper rpm range. Which of the above is the best choice?

 

The top one .

 

Many companies measure their advertized duration at a
different lift point. Therefore you cannot directly compare
one companies advertized duration against anothers. Without that lift point being known and the same.
They are different even for a cam with the same .050" duration.
Small variences in ramp duration and velosity of different design
cams of even the same .050" duration have more to do with
how the cam runs in the motor ( quiet valvetrain, valvefloat rpm)
than the power. the actual "running duration" of a cam has
more to do with the bleed rate of the lifters and other factors.
that being said.
As a general statement and trend the cam with the larger .050" duration and total lift will generally have more valve open area.
and will probabily make more power at high rpm.
Either of these cams will make more power than the one in your sig, at the expense of some low end torque, based on the numbers you quoted.
Cam#1 will probabily make the most peak hp.

 

Cam 1 will probably make slightly more power. I doubt it would be a 2% difference.

However, cam 2 will give MUCH better driveability, and probably noticeably better gas mileage, and will work better in a FI situation. It will require more valve spring.

Cam 1 looks like a typical older design; assuming the "lash" points of the 2 cams are measured the same way, #1 will hold the valves barely cracked open for a much greater portion of the engine's cycle than #2, without producing any meaningful flow. Cam 2 looks like a newer design with much higher "intensity".

Part of the choice would come down to the motor they were to be used in. If I were picking cams with the same goal you state, and it's a 350 with decent-flowing heads and a carb, I'd look for the next step up in the series that the second one is part of; if it's FI I'd probably use the second one.