I am in the market for a new cam, I dont think my current combo is being used to its full potential. It is a weekend driver with some occasional strip use. Current setup:

LQ4 bottom end
LS3 heads (unmilled) with 921 springs
TSP torquer V3 cam 231/234 .643/.598
LS3 intake
42lb injectors
1 3/4" headers (probably swapping to 1 7/8")
4.10 gear

I recently swapped to the LS3 topend when I blew a head gasket, and just feel like a cam better suited to these heads would help me pick up power I am leaving on the table. I know it doesnt help make power but I really like it when a cammed car "chops" and would like to get that sounds if it is possible. Any help would be great, thanks.

 

That cam isn't bad for those heads. In fact, a lot of LS3 guys like the SpinMonster cam which is a 230/234 .612/.598 114+2 XFI/XE-R Cam. So less overlap than what you have now and a later IVC.

But if you want to pick up everywhere, might I suggest this: 235/244 .621/.595 111+4. LSL/XE lobes.

 

Wow that is pretty similar. Im looking for something that really picks up on top end. I have had big cam cars in the past and the surging and drivability issues never bothered me any. I feel like I could pick up some top end with a different cam

 

Not sure what unmilled ls3 heads and lq4 ends up compression wise but if I had to guess I would say it's not ideal. If your compression isn't in the neighborhood of 11:1 or more, I would think you have more to lose overall than gain by going to a larger cam.

 

I have done a compression calculator and it came out to around 11.xx:1, cant remember the exact number

 

A stock bottom end LQ4 with 821/823 square port heads will be about 9.7:1. Not a lot of compression there, but it is not a deal breaker. Still better than the 317 heads.

 

Kind of what I expected. Low enough I wouldn't want to jump to a much larger cam. I went from a 5.7 to 6.0 with more compression but kept the same 230/238 size cam and I've been more than pleased with how it runs now versus the smaller lower compression motor.

 

How are you reaching those numbers? Thats not what I came up with

 

Here are the numbers from a stock LQ4 for a control:



Here are the numbers when you swap on a set of L92/LS3 heads and requisite 6.2 head gaskets:



You could mill the heads or use thinner head gaskets, but it will reduce piston-to-valve clearance unless you fly-cut the pistons to compensate.

 

Cool thanks, I wonder what info i put in wrong. I will definately need to mill my heads, I am wanting to go ahead and do a 408 bottom end anyways. This may be a good reason for me to do it lol