swathdiver

Cam across a post this website about a fella running a Cam Motion camshaft for about three years and 40k miles now, he picked up about 40hp if memory serves. The cam specs are 205 205 .510 .510 115+4.

Any comments on these specs?

RPMSpeed Tech

The TSP cam is way better than that and will make more torque. The lsa is a bit wide also. It doesnt need to be with a cam that small.

swathdiver

the LSA seems wide but so is my stock cam, it's 116. More torque where? Way better in what way?

Thirty some years ago we ran stock cams to well over 500hp with turbochargers and our LSA was 107 or 108 with lifts and durations much lower than these LS motors.

RPMSpeed Tech

You cannot compare a carb cam to a fuel inj cam. The lsa range youre looking for is 110-112. Above that it will make the peak tq and hp shift farther upward. Since the trucks normally shift at 5200-5600 you dont need that. Use the 112 lsa the stg1 cam comes with and youll be set. Itll keep the low end power you want.

swathdiver

Ok. If I went 5% over stock save for LSA for 5% under, I wonder how this would perform?

206 211 - 490 503 - 110

BTW - Those cars were fuel injected back then. Sequential Fuel Injection, very similar today.

RPMSpeed Tech

Most cams youll see in the comp book for fuel inj for lt1 and sbc are 110 and 112.
Going any more than 110 will give a very odd vacuum signal and the computer wont be able to compensate on older cars plus cause overlap even on a very small cam.
Why are you looking at percentages? Seriously the stg1 on a 112 will fit exactly what you want.
We have sold, installed, and tuned hundreds of ls cars and trucks. Itll fit what you want. You are entirely overthinking it for no reason.

swathdiver

Probably so. When I did this thirty years ago, all cams came up wanting, they actually slowed the cars down so we wisely kept the original camshafts.

With many things, a slight tweak is better than more more more and that is why I'm being cautious with it. I appreciate your taking the time to discuss this. What state are you in?

Well, when you talk about lobe separation of 110-112, what about the design of the factory camshaft with an LSA of 116 with regards to the computer and idle manners? My LC9s specs are 196 201 - .467 .479 - 116

RPMSpeed Tech

We are in Iowa. I routinely tow and haul ALOT with all 3 of my 2500HD 6.0s. As in 10k to 20k. I would not question using this cam at all in any of mine. I actually wish the stg 1 had just a tad more lift.

The stock cams arent designed with good power in mind. They have to pass all emissions, all the guidelines for their wnty underwriters, and pass fed epa regulations for underhood noise even and exhaust noise. That is partly why they are so anemic. You simply cannot compare the two. They have such low duration and lift the cams would run out of steam way too early on a tighter lsa so they widen it to help the power go longer.
The lobe design is also dated.

swathdiver

Thanks for your suggestions. Plan on doing this when it gets cooler down here in the south.

swathdiver

My project has been pushed off a while. I learned from Brian Nutter at Summit Racing that my LC9 actually has a different camshaft than originally thought.

From 2007-2009 the LC9 camshaft (12593207) was an AFM and Non VVT camshaft.
From 2010-2011 the LC9 camshaft (12625436) was an AFM and VVT camshaft.
The pistons on the latter have valve reliefs on the flat top pistons.

The specs are as follows:

12593207 - 193-193 .482-.482 116
12625436 - 196-201 .467-.479 116

The 3207 camshaft's specs are identical to the Gen III L33 High Output camshaft (12583623)

The LY6/L96 Camshafts are nearly identical to their Gen III LQ4 and LQ9 ancestors.

12625440 Gen IV - 196-208 .467-.479 116
12561721 Gen III - 196-207 467-.479 116

I finally got the specs for the L9H camshaft. This was a 6.2 Motor without AFM. Its predecessor (L92) and successor (L94) both have AFM, inactive in the former, active in the latter. The each have different camshafts.

L9H Camshaft - 12623065 - 198-209 .500-.500 115

So those older 5.3s used the same lift and duration but later ones had more lift and duration on the exhaust side. This seems to carry over with VVT engines.

Curiously, some engines like the L94, LH8 and venerable LM7 all have lower numbers on the exhaust side.

I wonder if the L9H or L96 would be better for a stock 5.3 when removing AFM?