Anyone know the specs. on the LS4 car/truck engine?

I'm about to get a 2007 Avalanche with the 5.3 LS4 DoD engine.
I will put in a little bigger cam and a set of Patriot Performance Stage II heads I have. My goal is to make another 50 rwhp. But, I want to know what the factory cam is before shop for a new one.

In 2WD models it generates 320 horsepower and 340 lb.-ft. of torque.
In 4x4 models it generates 310 horsepower and 335 lb.-ft. of torque.

Thanks!

 

Are you planning on keeping the DoD intact?

 

Yes, I will maintain the displacement on demand.
Why do you ask?

 

Because it might be very challenging to get a cam with decent overlap to still allow the motor to run on 4 cylinders. This, plus the rockers and springs may be limited on the amount of lift you can run.

 

sticking with the stock stall.... why not go with something like the CheatR or.. some other came with hardly any overlap?

 

I was told that the DOD engines use different lobes and lifters on the DOD cylinders. So if you intall an aftermarket cam you will lose the DOD.

I have an L92 engine with DOD and I plan to change the cam and lifters. I will post more as I figure it out.

There may be people here that have done this swap already.

Robin

 

my mom bought a GXP, and it seems to me as if the aftermarket isnt up to the task of engineering a DOD compatible cam

 

I have wondered this myself as well. Could you swap in the L92 or L76 camshaft into the DOD 5.3? I know this is oversimplifying things, but in old muscle cars a decent big engine cam turns pretty radical in a smaller engine.

 

I have not seen any company come up with a performance cam for the AFM/DOD engines.

Considering more v-8's are coming from GM with AFM/DOD -vs- without I can't figure out why the aftermarket hasn't started designing cam's for them yet.

An idea to help you reach your goals of 50hp increase right now would be a set of longer rocker arms, the patriot heads you already have and maybe a set of shorty or LT headers for your vehicle. Along with a Filter upgrade (possibly filter box upgrade).

Just an fyi on the lift increase with the different rocker arms.
1.70" rockers are the stock size for LS1/LS2/LS4/LS6/L76/L92 motors
1.75" rockers increase the max lift by 2.94%
1.8" rockers increase the max lift by 5.88%
1.85" rockers increase the max lift by 8.82%

Respectively if the stock cam has a max lift of .525 then a 1.75" rockers would up it to .540", 1.8's would put the lift to .555", and 1.85's would push it up to .571" for max lift.

Now one thing I'm wondering is if the Patriot Gold .650" capable dual springs would be to much for the stock cam or the DOD lifters (possibly to much back pressure)???

You might give Comp a call and see if they can cut a dual pattern cam that will stay under the AFM/DOD lifters max lift spec's. Say something in the 22x/22x range with a 4 to 6 split (ie exhaust lobe larger then intake lobe).

 

It would be far more simple to just disable the DoD and replace the lifters with LS6's, you would lose a few mpg, but you could run any cam you wanted

 

I had hoped my journey wouldn't get too involved, but I may go for a custom grind camshaft. I thought about the SLP rocker arms to, and figured that might be an alternative route. The thinking about the Patriot springs being to stiff to work with the special lifters is something deeper to ponder.

I've searched truck sites, engine sites and even the general internet. Maybe something will pop up. I would think the market will open up when the DoD Camaro engine hits the streets. In the mean time I will call CompCams.