are the cam specs the same on the ls3 as ls2?

 

Almost identical per the following:





This was from a recent article on the corvette action center

 

That's interesting.... gives you a lobe profile sheet for the guys at GM from what they have to play with.

The LS3 stock cam is a combination of the LS6 cam. It takes the 02-04 LS6 intake lobe and combines it with the 01 exhaust lobe (same as LS2 exhaust lobe)

So the cam turns out to be a 204/211 .551"/.525"

No clue on the LSA though, probably the standard 116-120 that all OEM cams are on here at this point. (EDIT I didn
't see the centerlines on the data sheets to start with!)

Bret

 

I get the IVC and EVO (.05) if I assume the cam is 204/211 117 -4. The ICL and ECL don't exactly match the table.

However if you look at the IVC of the LS2 vs the LS3, there is a 1* difference, yet the ICL is 2* different even though the duration for both is 204*. There must be some rounding in the numbers.

Close enough for now or until someone with better math skills than me solves the equations.

 

Man how did I miss the centerlines in that chart....

It's a 117.5 -2.5° on that chart

The intake is actually on what we would consider at 121° ICL, exhaust on a 112.5° ECL if you go off the open and close numbers at .050"

That's a 116.75° LSA with -4.25° retard.

The lobes must be asymetrical.

Bret

 

thanks for the info. for the first time, I just realized the stock gm cams are ground with retard. very interesting info.

 

that 02+ LS6 cam is a monster on the exhaust side for a stock small displacement camshaft, no wonder those cars regularly beat up C6's on the tracks. I bet you could increase HP by slipping in a 02+ cam in an LS3.

 

you would think it would without effecting drivability!...they must have tried it but for some reason the I/E (intake to exhaust flow) though greater in the LS3 heads versus the LS2 heads needed a cam that was counter intuitive to what you thought would work best. I am no expert and this is being bantered around LS1 TECH. I wonder what a Thunder Racing CHEATR stealth cam might do in an LS3

 

When you look at the huge gains on LS3 cars from headers, I'd bet a CheaTR would do very well. Withe the extra cubes you could easily go a bit bigger and be totally stealth too.

 

Well your not going to find any "experts" over there anyways....

Most likely the 02-04 LS6 cam or exhaust lobe was not in the LS3 because of emissions, it definitely would make more power with that cam.

Bret

 

an engineering article discussing LS6 01 versus LS6 04 by Chevrolet engineers revealed the 03/04 cam was worth 8-10 RWHP over the 01 cam.

 

with the added displacement and the new head design i bet the LS3 would pick up another 8-10 rwhp and hardly notice any difference in driveability or idle.

 

And the LS2 camshaft has the same lobes as the 2001 LS6 camshaft (but doesn't have the reluctor wheel machined in the camshaft since the sensor was moved to the timing cover).

The 2002-2004 LS6 engines had lighter valvetrain (hollow intake and hollow/sodium filledexhaust) compared to the 2001 LS6 and the 2002-2007 LS2 valves.

GM may not have gone to the 2002-2004 LS6 exhaust lobe for emissions (overlap) reasons or it may have also been for cost reasons if they feel the 2002-2004 exhaust lobe requires the lighter (but more expensive) valves.

The 2002-2004 LS6 camshaft would be a power gain for a 2001 LS6 and for an LS2 engine. Probably only a small gain on an LS3 given the much smaller difference between the two (exhaust lobe). You could probably just switch to 1.8 rockers on the exhaust and get more gain.

BTW - you can put the older camshafts into the newer engines (Gen III engine camshafts into Gen IV engines) without any major changes needed. To go in the other direction (LS2, LS3 or LS7 camshaft into an LS1, LS6, LQ4 etc) would require changing the front timing cover, the timing gear and then getting an extension wire to go from the old camshaft sensor harness location to the front timing cover (these extensions are available).