Roller cam vs hyd/solid cams

[Tic's60]

I am thinking about changing to a roller but been trying to figure out more about the lift, lob seperation on rollers vs flat tappet type cams.

Normaly I prefer a split lift type, current cam is 551 Int 571 Ex, but I cannot seem to find a roller like that. Most are larger. Are roller cams normaly bigger?

I like the less friction and valve wear comments I have heard about them as well.
Mind you I have never run one myself so I am just looking for info not a war on cams.

And this is a 66 Rat as well. Oh and it red lines at 9800 (just kidding)

 

[Skip FIx]

Get one custom ground with what ever specs you(or you and the cam tech) decide on. There are alot of solid "street rollers" now as well as hydraulic rollers. Comp. ,Lunati,Bullet all have alot of lobes to choose and grind it on whatever lobe sep you want. Don't just look at the catalog generic ones.

Advantages for rollers-no break in and worry about lobes going flat, quicker valve action for more "area under the curve" with less seat time for better idle than a flat tappet.

 

[Tic's60]

After spending some time with Crane Cams here's what my cam a Hyd flat tappet translates into a roller

translates from Hyd
Intake @Cam 325 @Valve 553 All Lifts are based
on zero lash and theoretical rocker arm ratios.
Exhaust @ Cam 336 @Valve 571
Rocker Arm Ratio 1.70

translates to roller
Lift: Intake @Cam 362 @Valve 615 All Lifts are based
on zero lash and theoretical rocker arm ratios.
Exhaust @ Cam 374 @Valve 636
Rocker Arm Ratio 1.70

Mongo difference between them. But Mongo like. Blazing saddles has always been one of my favorite movies :-)

And though stupid on roller cams I was right about thier lifter numbers being way higher than flat tappets cams. Though not an apple to apple comparision by no means.

 

[Skip FIx]

As I said there are numerous lobe availabel that can be ground that give different lifts.

It is better to look at duration that just lift. That affects how the cam wil act in the motor more than the lift. You can have a short duration high lift cam with agrressive lobes that will still idle like a smaller cam.

 

[Skip FIx]

Here's a list of the Comp lobes
http://www.compcams.com/Technical/Catalogs/LC2005/2005LobeCatalog.pdf

 

[dq409]

You will also have a better idle with the roller IMO and a quicker rev ,,,