[NC Cams]

"...So Basically This Is Why A Roller Cam Is So Much Better..."

Not necessarily. We did a test wherein we made 2 cams, flat and roller. Both gave EXACTLY the same valve motion. The roller made more torque at speeds below 5000 rpm. Above 5k, they were IDENTICAL in peak power output.

A roller can, however open the valve at a higher velocity for a given duration because you won't run out of lifter fact to rub against. For example, a tapped that is 0.842" diameter can only tolerate a max velocity of 0.00069"/deg. A roller that drops into the same lifter bore can go to 0.0085" or more. This faster rate of lift for the given duration usually makes for a more responsive engine if valve motion is not constrained in any way.

HOWEVER, you can NOT accelerate the roller follower as hard as a flat tappet due to the intertia load induced stresses that develop. The rollers are more fragile as the load carrying elements are smaller in cross section and thus not as strong as a flat tappet.

Anything you do to lift more (more rocker or more lobe) will squeze the spring more. You only have so much travel available. When you use it up, you're done - unless you change springs or make other adjustments to accomodate for more lift.

[camprofile]

Hi to everybody ! Im a DIY guy from the Philippines, I reprofile camshaft for small underbone motorcycle, SOHC, Twin Cam, push rod engines for drag and circuit racing i learned a lot from you guys, more power! I love this thread:wave:

[FPV_GTp]

Hi camprofile , that looks super quick ! how fast does it go down a drag strip?

Did you grind the camshafts yourself?

cheers

[FuddMcDee]

this thread is almost 5 years old. that engine is prolly blown by now

[camprofile]

Hi camprofile , that looks super quick ! how fast does it go down a drag strip?

Did you grind the camshafts yourself?

cheers

Hi FTV_GTp, the bike is a Honda Wave 125 cc bored and stroked to 235cc, the cam is a roller grind with 90 deg overlap, 110 deg lobe sep, and 310 deg duration . Is still the fastest in his class said the owner running in the high 13 sec in 1/4 mile. Yes I grind racing cams. https://www.facebook.com/llcamllprofilell
:cheers: