[turchiac]

I thought that one the benefits of a roller cam was the ability to have higher lift numbers with less duration @50 which would provide good low speed torque and throttle response with good top end power as well. I'm looking at these two cams with pretty much the same advertised duration and close duration @50, however the flat tappet cam has more lift than the roller cam, would this cam make more power because of this increased lift? I know that i can call the cam company's but the more input the better thanks

XE274H 230/236 @50 with 552/555 lift 110 lsa

XR276HR 224/230 @50 with 510/510 lift 110 lsa

Engine is a 9:1 454 don't know exact compression, flat tops with 101cc heads.

[SSedan64]

Three-Way Cam Lobe Shootout
http://www.carcraft.com/techarticles...test_time.html

[turchiac]

Thank you for your reply SS sedan, very good article. The roller cam in this test has more lift than the flat tappet. This is why im confused by the two cams above, the roller has similar duration but less lift. It seems that comp cams hydraulic rollers don't have more lift than they're comparable flat tappet designs. Confusing?

[SSedan64]

The way the Roller cam lobe is shaped allows much more duration from mid to max lift than the Flat tappet. So, you can get more air flow with less lift with a Roller.

[turchiac]

Ahh ok. Never knew that thanks.

[ap72]

two different cam lobe designs. there are flattappet cams with more lift androller cms with less lift.

[turchiac]

So given the same engine combo the roller would make similar power of the flat tappet with less lift?

[ap72]

Originally Posted by turchiac

So given the same engine combo the roller would make similar power of the flat tappet with less lift?

Simmilar yes, but not as much.

[turchiac]

ok cool thanks