Let's say I have a 2012 SS Camaro w/LS3.

Let's say I install a 416 shortblock under stock intake manifold and heads and exhaust manifolds with stock cats and exhaust.

Let's say I realize I will cost myself probably 100 or more HP this way.

Let's say I want it to idle just like stock, no detectable lope.

What (approximate) cam would you put in it? 22x/22x? smaller? I believe the stock cam in the car is a 204/211 on like a 117.... I want the biggest cam with no lope, I should specify....I don't plan to put the stock cam in it....

 

Lingenfelter's GT series cams are enormous but dont really lope at all due to the huge LSA. Might look into a GT11 or GT13 cam.

 

the lobe seperation is what gives the car its lope(LSA). i dont think the duration has much of anything to do with it. the higher the LSA the less it lopes. i have heard a 220/220 cam on an ls1 that sounded lopey as hell, the cam was on a 110 LSA

 

so then how wide of an LSA can I go without ptv issues? 228/232 on a 118? :-)

my race car is old school 327 and I don't know much about the LS3.

 

i dont know really. id ask patrick g that one.

 

With a 416ci you'll be able to get by with a lot less negative overlap, maybe a 222/234 115lsa
EPS has a option too.
http://www.engpwrsys.com/index.php?a...&productId=109

 

if u want ZERO lope, id go with 116-118 LSA

 

Let's say you go with an LS7 cam.

 

I have an LS2 with the Lingenfelter GT11 cam. This is a pretty odd cam but it works well on the LS1 and LS2 heads. The specs are 215°/231° duration and .631" / .644" lift on a 118° LSA. With all my mods, I make 473 rwhp / 426 rwtq with zero lope at 700 rpm. This combo has great torque idle to 6000 rpm.

While this exact cam may not be the best choice for an LS3, the key as most people know is to keep a negative overlap. Big overlap cams are not the way to go on the LS motors as you are trading idle and torque for slight more top end power.

The GT11 cam has -12° of overlap. Again....negative overlap which means there is no valve overlap since both valves are closed for 12°. The high lift gives air flow which helps offset the short duration. Because the LS3 heads flow so well, I would think the same idea would work very well.

For the LS3, I was thinking because of the bigger intake head ports, you can keep the intake duration below 220° and exhaust around 230° - 234°. Then keep lift around ~.600" with a 117° LSA.

Here is a link to the You Tube video at idle.

http://youtu.be/JLwsSMRC4JI

 

i have heard the GT11 is hard on springs is this true?

 

I don't find that to be the case. I am using Patriot Gold springs. I had them checked at 20,000 miles and they were exactly at the published spec. Springs are not that difficult or expensive to change.

Of course, valve spring life depends on a number of factors including how much and how long they are run at high rpm and at what temperature.

Springs technology has improved so I really don't find that to be an issue.

 

I run the Lingenfelter GT9 on my LS2. Idles nice and smooth, no lope at all. Just what I wanted

I did run it n/a for a few weeks before I hooked the blower back up, and I was pleasantly surprised with the engines performance. No dyno numbers though. It was happy to spin to around 7k on a 382.

Just gets better with boost lol

 

overlap is what makes the cam lope. LSA doesnt entirely dictate how ahrd it will lope.