Is it possible to run mechanical roller lifters on a hydraulic roller cam? I would like to run a roller cam in my 73 350 but don't want to pay for retro-fit hydraulic lifters.

 

No. The profiles are taylored to the type of lifter being used. Solid cams have a lash take-up ramp that hydraulic do not, for instance.

 

Ok then does anybody know of a good mechanical roller cam. That has good low end torque and decent horsepower.

 

Go check out the Crane and Comp Cams websites. They have scillions of them.

Just remember that a roller cam will have less duration at .050" lift than a flat tappet cam of the same advertised duration. Roller cams can't get the valve to .050" lift as fast as a flat tappet (beleive it or not it's true). Buy beyond that- WATCH OUT! The valve REALLY moves after that!

So look for something with about 270-280* advertised duration designed for a N/A motor. Should give good midrange punch and decent HP.

Don't forget you will absolutely need matching valvesprings- don't even think about running stock flat tappet springs against a cam like this.

 

I don't think thats true i was just looking at some cam specs and there is definitely more duration with a roller cam. That would'nt make any sense that a flat tappet could ramp up faster.

 

To my understanding, on two cams with the same lift, the one with less duration is ramping faster.
A roller profile can more aggresively ramp the roller lifter than a flat tappet. The reason it has less duration is because it doesn't need it to keep the lifter from digging into the lobe as a flat tappet would. A roller cam can have the same lift with much less duration. Flat tappet profiles have longer duration by neccesity to avoid the lifter digging in.
Again, this is as I understand it.

 

Look at the relation between Advertised duration and duration at .050. This will tell you how aggressive the profile is.

For example, a Comp High Energy Street roller with an adv. duration of 280 degs has a duration of 236@.050.

A Comp XE Solid Roller with the same 280 deg adv. duration has a 242 deg duration @ .050.

The XE has the more aggressive profile.

ME Leigh - I happen to have a Comp XE Solid roller cam for sale. Advertised duration is 274/280, 236/242@ .050 ,
.564/.570 lift with 1.5 rockers. Email me if interested.