Cam lobes explained
Thread Starter
11 Second Club
iTrader: (24)
Joined: Mar 2008
Posts: 2,554
Likes: 2
From: North East, MD
Cam lobes explained I never realized so many existed for the LS motors. Anyone have a Lobes For Dummies that I can see just what is different about them... whats the best?
Thread Starter
11 Second Club
iTrader: (24)
Joined: Mar 2008
Posts: 2,554
Likes: 2
From: North East, MD
Because this is my current cam:
http://www.compcams.com/Cam_Specs/Ca...csid=1088&sb=1
and I think it is XR lobes. I want to order a bigger cam this week and looking for what's the hot lobes.
http://www.compcams.com/Cam_Specs/Ca...csid=1088&sb=1
and I think it is XR lobes. I want to order a bigger cam this week and looking for what's the hot lobes.
Different lobes have different ramp rates as to how fast they open/close the valves. Good for power, bad for valve springs lol.
My cam is on XE-R lobes and it runs pretty good.
Best thing to do is call a sponsor or Comp cams and talk to someone about what your wanting from the car/engine, ask about lobes and see what they say.
My cam is on XE-R lobes and it runs pretty good.
Best thing to do is call a sponsor or Comp cams and talk to someone about what your wanting from the car/engine, ask about lobes and see what they say.
Trending Topics
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
There is more to it than this but someone like PatrickG will have to explain the rest.
If you know the advertised duration (.006) of a cam you can calculate the ramp rate. To do this you take the duration @.006 and subtract it from the duration @ .050. A number of 53 or higher denotes an XE lobe or other mild lobe and a number of 49 or lower denotes an XE-R lobe or other aggressive lobe.
The discussion was about EPS lobes but the idea is the same for all lobes.
The new Hot Rod magazine has a good cam article that explains a lot too.
If you know the advertised duration (.006) of a cam you can calculate the ramp rate. To do this you take the duration @.006 and subtract it from the duration @ .050. A number of 53 or higher denotes an XE lobe or other mild lobe and a number of 49 or lower denotes an XE-R lobe or other aggressive lobe.
The discussion was about EPS lobes but the idea is the same for all lobes.
The ramp rate from .006" to .050" for the EPS lobes is 49 degrees. This is fast, but ramp rate is not the only determining factor in how spring friendly a cam is and how stable it will be at rpm. Acceleration and jerk are much more important factors and it is here where the EPS lobes are superior to the XE-R lobes. Acceleration and jerk are much more controlled with the EPS lobes vs. XE-R lobes even though they match the XE-R lobes at 49 degrees and have more lift.
Thank you, that was very helpful. I wasn't looking to completely understand how each lobe works, just how they differ and how to determine which is which. Thank you for your help.
guys you are making his question seem way more complicated then he's really asking.. I don't believe he wants an explanation on how ramp rates work or how to calculate them.. I believe he is asking what types are the MOST aggressive to LEAST aggressive i.e LSL LSK XER XR etc. Rank those in order for him and I think he'll have his question answered.
Joined: Aug 2007
Posts: 24,241
Likes: 89
From: Turnin' Wrenches Infractions: 005
Well, everyone is sticking to explaining comp lobes, which is great and all but I want to mention Cam Motion. Their lobes make power, and open and shut valves very quickly. They accomplish this in one way by running a smaller then normal base circle. Doing so is very common in aftermarket cams, however, with Cam Motion lobes it is more pronounced.
Here is an example of 3 different line of Comp lobes, the XE-R is the least aggressive and the LSL and LSK are the same, the lower number difference between the .006 and .050 lift is the least aggressive.
PHP Code:
Type Lobe# 0.006 0.050
Xtreme Energy XE-R 3722 273 224
Xtreme Energy LSL 13017 277 227
Xtreme Energy LSK 2127 277 227
