ihdude

iTrader: (1)

How much does lobe design play into selecting a cam? What are the pros and cons of different lobe designs? I would assume a fast ramp lobe design would produce more HP but how much more? Is a 228/230 cam going to have much difference if the only thing that is different is the lobe design?

SOMbitch

iTrader: (8)

No not much Hp difference as most LS1 cams today have a lobe intensity hovering around 50 +/- a bit. If I were getting a new cam today I would strongly consider the relatively new EPS lobes or Comp LSL. Here is a good read on the LSL lobes>>>>https://ls1tech.com/forums/generatio...obes-comp.html

LTX355

iTrader: (15)

I would say lift will play a bit more into the hp when u have aftermarket or ported heads. depens what ur plans r with x setup and what u use it for.

ihdude

iTrader: (1)

Thanks for the link.

Some lobe designs are hard on the valve springs right? Do I gain anything for the aggressive lobe that is hard on springs? I see that the EPS lobes are easier on springs and are quieter. What are the pros and cons of the different lobe designs?

EPS, XER, LSK, LSL and I'm sure there are others.

Nitroused383

iTrader: (10)

More agressive ramp rates tend to be designed for higher torque / lower rpm applications. This mainly applies to hydraulic roller profiles though. When you design / use lobes for higher rpm applications (7500 + rpm) people tend to use less agressive lobe profiles.

soundengineer

iTrader: (16)

the basic thing to understand is the take off and landing of the lobes... this is where most of the "abuse" come from
a lobe that takes off quick...also comes down quick... a lobe that has a softer take off has a softer landing as well...
a lobe can be designed to take off quick and land a little softer or vice versa...
the trade offs between all of them is so minimal that you wont see it on a dyno...
you may see a small difference in the lower end of the rpm, but its only going to be a few ponies...nothing to write home about.

the benefits come in to valvetrain life. the softer the take off and landiing, the longer life you get out of the vallvetrain
the more agressive, the more often you have to replace parts.

if you want your valvetrain to last longer you go with a less agressive cam with a softer lobe.. if is all out race you go for a more agressive cam and replace parts more often.

unfortunately theres not really an agressive cam with a soft lobe...yes the lobe design can be softer than another one...but really..if you have a 246/248 with .640/.660 ....its not going to be easy on the valvetrain no matter what lobe you go with... the physics of the space you have to work with says it all.. limited time, limited space...

Nitroused383

iTrader: (10)

It all comes down to valvetrain stability for your setup. Too agressive of a lobe for your setup will cause valve float and wreck valve seats, valves and even hit pistons. A 224 lobe with .650" lift will also be more agressive than say a 250 lobe with the same lift. Its just the nature of the beast.

racer7088

Right the lobes are basically designed with certain assumptions in mind as to RPM and spring loads and valve train mass and stiffness as well as noise etc.

If you have lighter parts you might be able to turn more rpm with the same lobes or use a higher ratio rocker.

With smoother lobes you can sometimes run heavier parts to the same rpm or run higher rocker ratios etc.

Some lobes that are more modern in design have filled in the area on top of the nose and are actually higher peak lobe lift AND are more stable at rpm.

It all depends basically one what you want to do and how much rpm you want to turn. If you are at lower rpm you can have more aggressive lobes with more area and make more power probably everywhere until that system goes out of control.

I am doing some much higher lift stuff .700-.750 that will also turn much more rpm for drag racing and large engines with larger heads but it will need a special spring and decently light valves etc and roller rockers but will make more power up in the mid range and higher rpm areas.

The LSL is a great all around lobe it seems with good doubles with some good pressure on them like the new Comp 26926 or the PRC EHT or even the other higher load doubles like the Patriot Xtreme etc. With true LS6 valves you could probably even use a beehive on them since the valves are so damn light on the LS6.