stmotorsports

So I had always planned dropping in an LS6 cam into my LM4, but the more I'm thinking about it, is there even much point if I'm going to be running an auto trans in pretty much stock form? I'm not really planning anywhere near any kind of sick built setup or even all that much hp, this is just a repower in my 54 Belair that I would like to wake up a bit.

Thoughts?

StealthFormula

iTrader: (35)

Take a look at this article where Hot Rod tested several different factory GM cams and a couple of aftermarket ones vs. the stock LM7 cam in a 5.3 motor, you may find it interesting:

http://www.hotrod.com/articles/ls-cam-test-comparison/

Note: Unfortunately, it appears as though Hot Rod goofed up when they did the LS6 cam comparison as the specs and results they provided for the LS6 cam are actually of the LQ9 cam so I would ignore that particular comparison even though it's the most relevant. Check out the test they performed for the LS2 cam (which is the same as the '01 LS6 cam), although not the same as the later '02-'04 LS6 cam it will still give you a rough idea of what to expect.

redhernandez

are you planning to do anything else to the motor?

stmotorsports

I've read that article and am plenty familiar with how different cams react in different motors. But that's kind of my point- seeing how the vast majority of "performance" cams will cause a 5.3L to lose low end power, I'm wondering if it's even worth it because no automatic will generally shift as high as you can spin a manual. So any potential top end gains will be far outweighed by the loss in low end power. Just like a diesel- if you can only spin it to 3500 who cares what kind of power it could theoretically make above that

I do have an LS1 intake, injectors, rails and coils on it mostly just for underhood aesthetics but no not really looking to do much else with it

StealthFormula

iTrader: (35)

The fact that your car is automatic makes no difference, all you need to do is have your tuner adjust the shift points to be optimal with whatever cam you choose. My firebird has a 4l60e and the wot shift points have been adjusted to ~6400rpm to take full advantage of my cam and head work.

If you want a little more juice I'd get yourself a nice converter unless you already have one. Best mod for a automatic car IMO.

Darth_V8r

iTrader: (4)

Maybe this is relevant. I put a LS6 cam in my 5.3L in my suburban and I hate it.

I lost efficiency, and torque.

The LS6 cam is good if you have compression but the truck motors don't.

Personally I recommend getting a drop in truck cam from cam motion even though it's going into a bel air. I think it'll be more fun to drive that way

NAVYBLUE210

Agreed! Drop in truck cam from Cam Motion talk with
Kip and go with his recommendation. You can pick up
20 rwhp but more importantly 15-25 lb ft throughout
Your driving range (1500-4500 RPM) much more
Enjoyable with no loss of economy. Check out
Thunderstruck507 results in Dyno section for
Drop in truck cam.

gagliano7

The best overall cam for the 5.3 is the 212/218 cam. Many guys on the truck forums use this cam. The LS6 isn't made for a heavy vehicle like yours. Plus like Darth said your 5.3 has a full point less of compression compared to the LS6. Alot of truck guys were disappointed with the LS6 cam in a 5.3.

Darth_V8r

iTrader: (4)

Lol! I've made it my mission to help guys NOT repeat my mistakes

stmotorsports

Thanks for the insight guys I def appreciate it.

V8r yeah I could definitely see an LS6 cam sucking ***** in a burban.
But my car is never going to be anywhere near that heavy. Plus what kind of gearing does your truck have? And I'm assuming not, but do you tow with it?

Don't forget a huge chunk of the published curb weight on older cars like mine figures on the old solid cast iron straight 6 and iron case trans, accessories, etc. Ditching all of that stuff in favor of lighter weight stuff saves a ton of weight (literally?)...

So that's kinda my apprehension about going with more of a truck upgrade cam. Not that adding tq is ever a bad thing. I'm just thinking ideally if I'm going to bother with a cam swap, I want to add as much hp as possible while sacrificing the least amount of tq. I don't necessarily need to add any tq since where it's at now should be plenty. Plus I still need to swap the rear so I can go with whatever gearing. Kinda was thinking 3.73s(?)

But losing almost as much low end or more than the top end you're adding definitely doesn't make any sense to me at all unless we're talking about some featherweight racecar

Darth_V8r

iTrader: (4)

Many of the truck cams are bigger in duration than the LS6 cam - AND they have a tighter LSA, which will help build torque right off idle, carry better past peak, and sound cooler.

The LS6 cam is designed for LS6 compression not 5.3 compression.

gagliano7

I put a 222/226 115+3 .600 .600cam in my 5.3 with tsp 5.3 heads 58cc . It runs pretty good but the 212/218 113+4 .530 .530 cam with the tsp heads still felt better to me overall. If i wasn't upgrading to a 6.0 i would go back to the 212/218 cam. My truck weighs 3700 lbs with a 5 speed with a low first gear and 3:42 gears.

Darth_V8r

iTrader: (4)

My current wet-dream cam for the truck is 214/224-112+4. Wouldn't rev for squat, but should be a torquey ****.

gagliano7

That would be a fun tire burner.

dlewis

Darth_V8r

What kind of powerband would the 214/224-112+4 cam have? Can you compare it to the cams below?

Cam Motion LS 5.3 - 10 Stage 2
Duration at .050 - 210/215
Lift with - 1.7 - .518/.510
Lobe separation 114
Intake center line 110
Usable RPM Range 1400-4600

Vinci 080 "Ultra Torque"
DUR @ .050" 210*/218*
LIFT .551/.551
LSA 116*
2A

BTR Truck Stage 2
212/218 .553/.553 113+2

I have a 2007 crew cab Sierra with 3.73s and 33" tires. I'm looking for more torque and prefer to keep the stock converter and don't need or want to rev past 6000.

Darth_V8r

iTrader: (4)

They all should have very similar power bands. I just think mine would make a bit more mid range torque than the others and sound a little cooler due to decreased negative overlap. Possibly extend the RPM band a little bit

Moddoo

iTrader: (4)

Some good advice here.

I have a new 212-218 112 cam and springs for sale in the classifieds right now.
Dyno tests show no loss of low rpm torque down to 2000rpm.

If you want to feel some more low end compared to stock, try the comp xr259hr.
206-212 112
I had a lot of fun with this as my first 5.3 cam in a heavy truck.

My 5.3 build turned into a 6.2 build, so I will be getting a different cam for that.

dlewis

Thanks for the response Darth_V8r!