Cleb98

Recently purchased an ls2 cam to use in my 5.3...will i need to get the newer timing cover with the sensor in it?

Mercier

iTrader: (15)

Yep. No provision for the cam sensor on the rear. Also Racetronix part or similar to extend the cam sensor harness to reach the front. There was a split in the LS2s where some had a 1x cam gear and some had 4x(and 24x vs 58x crank reluctor but that isn't your concern) So make sure you get the right sensor and cam (timing) gear combo. The cam itself should be the same. My LS2 is 05 Vette and it seems to be 1x with a 24x crank reluctor(because it is running with my 2000 LM7 harness and PCM).

Even if you need to go to the 1x cam gear, that's cheap.

Hope you are doing some valve springs with that cam. It will likely destroy LM7 springs. And LS2/6 springs are cheeeeeap.

Cleb98

So ill need to get the newer timing cover, harness extension, possibly 1x cam gear? new sensor? Also ill be running the cam with Comp springs that are .590 lift max so more then capable

Cleb98

Will I need a different crank sensor?

Mercier

iTrader: (15)

If the crank sensor was correct for the engine before, changing the cam won't affect that.

96capricemgr

iTrader: (1)

The smaller displacement will cause the rpm range to rise given a particular cam, coupled with the fact you probably don't have the hollow/sodium filled lightweight valves you really think LS6 springs will be OK?

http://www.hotrod.com/how-to/engine/...st-comparison/
They floated the valves with the LS2 cam just 100rpm past peak with unnamed "upgraded beehives" which lets face it were probably LS6 since those are cheap, had they used even a Comp 915 beehive they wouldn't have had float.

thunderstruck507

iTrader: (18)

A lot of work and extra parts for an ls2 cam. This is in a swap car and not a truck I hope.

Darth_V8r

iTrader: (4)

^^^Listen to him^^^

I put an LS6 cam in a LM7 in a suburban, because I thought it would be a great idea. I've never really been happy with it. You would do far better to spec out a cam that fits and has a profile designed for what you want. The only thing I can say about what I did is the exhaust note sounds way better than stock. Didn't pick up the power I expected or where I expected it. Early LS modding mistake and lesson learned

96capricemgr

iTrader: (1)

More folks should admit their mistakes to help others avoid them.

Cleb98

Yeah, motor is going in a swap car not a truck. The LS2 cam I got was from an 06 TBSS. From what I have read the 06 TBSS used the 05 LS2 platform that still had the 24x reluctor wheel. So in saying this, from what I have read ill just need the harness extension, sensor, and cover. Trying to make this cam work because I basically got it for free. Even with the cost of the things I listed above, its still cheaper for me then buying an ls6 cam.

Mercier

iTrader: (15)

Hi guys,

I thought LS6 springs = LS2 springs. Or has GM just combined the parts and the current LS2/LS6 (blue) springs are a bit better than the original LS6 (yellow) springs? Not saying they are a are best springs for the application and also not saying that a stock LS2 can't produce some valve float, but LS2 cam comes in a motor with LS2 springs and no hollow valves. What am I missing?

96capricemgr

iTrader: (1)

Did a little digging and it does seem that LS2 used solid valves with the LS6 cam so that is encouraging BUT that doesn't mean GM wasn't fine with float from the factory. Lots of applications benefit from spring upgrades on a factory cam.

Mercier

iTrader: (15)

I suspect that GM knows the LS2 cam can float a bit somewhere past 6K. It occurs to me that floating at .525 lift could be considered "safer" than floating at .600-ish lift of many popular aftermarket cams. As long as the ramp isn't steep enough to be "bouncing" the valve to higher lifts(which I hope isn't the case with stock cam), that's .075 breathing room.

Call it PTVWF clearance ("piston to valve while floating")

96capricemgr

iTrader: (1)

The other consideration is the 5.3l may want more rpm than a 6.0l with the same cam depending on if the heads or intake choke it sooner. More rpm means more spring needed. Maybe the smaller valve is lighter enough to help.

Greater point though is there is more to a matched setup than cam and spring.

Darth_V8r

iTrader: (4)

My point wasn't "get the ls6 cam instead"

My point was it was a lot of work for an upgrade to be disappointed in. The ls2 cam isn't great even if free. Neither is the ls6 cam even if free.

Mercier

iTrader: (15)

And my only point was that it could live with cheap springs.

If there is money in the budget for aftermarket cam, definitely the better route if you're already doing the work. But in a higher-revving application, I think the LS2/6 cam is pretty nice for a 5.3.

See this article below..this is crank numbers but hard to argue with. LS2 cam in a stockish 5.3 gains:
5,500 +46 lb-ft (48 hp)
6,200 +67 lb-ft (78 hp)

With a loss of 18 lb-ft at 2500RPM.
How much loss at 800-1200? Probably a lot more but we're not in a truck anymore right?
http://www.hotrod.com/how-to/engine/...st-comparison/

I've posted that link before several times but it's just good info.

96capricemgr

iTrader: (1)

It peaked at 6100 and floated before 6500 with brand new springs.
For peak performance an engine needs to be turned solidly past peak hp so you use the top of the curve not just the uphill slop and again this was new springs. What would it do a year or two later?
A car intake instead of the truck one might shift the rpm range a bit too.

I wish the article told us what springs they used but I am quite sure the float they saw is THE reason they didn't specify the spring. Magazines are terrible about protecting advertisers. It they were aftermarket that would not have flown and if they were LS2/6 springs most magazine readers wouldn't comprehend the float with the solid valves and such and would have bashed them.

This is an interesting article but most magazine stuff is just advertising and should be viewed with skepticism or researched elswhere. They have a Edelcrap heads/cam/spray Caprice that is slower on the jug than my car is on true street tires with tools and slicks in the trunk stock shortblock with ported GM heads and intake.
The Edelcrap intake HURT power and they try and excuse it etc. Then there is the Granatelli article where they compare a high mile original airfilter dyno run to a run with a new MAF and airfilter........
It is an exception when magazines have useful info. It is fun to see the results of testing a bunch of stock parts which is only done as advertizing for the dyno shop.

Mercier

iTrader: (15)

Same problem I had with Mythbusters. Most articles are too hung up on their own hunches and change multiple variables at once without following a real scientific process. Frustrating because you read or watch the whole thing, they declare victory/defeat/learned something, and I feel like it was just a big inaccurate and inconclusive waste of time.

-BUT- that article gave me hope. It's far from flawless but about the furthest in the right direction I've seen in some time.

So let's contemplate this question: If the feeling in the thread is that better springs are needed for aftermarket or the LS2, assuming springs will be purchased, why are we so down on a gain of 67 lb-ft (78 hp) for a few hours of work and some factory parts that can be gleaned from a junkyard? (ok; a harness that you can buy affordably or extend yourself for a dollar in wire)

Better cams exist for sure but 78HP in an afternoon is not bad IMO if budget is a constraint.

If float is a concern, what's wrong with LS2 cam, LS2 springs and shift at 6250-ish? Gains at 5,500 are still significant: +46 lb-ft (48 hp). At 6000 we are probably up ~65HP.

A.R. Shale Targa

iTrader: (2)

01 LS6 cam is the 525 lift on both lobes
02-04 LS6 cam is 204/217---.551"/.547"
LS2 cam is 204/210---.525 on both lobes
My question is; Why use it ??: even though it's free the article which tested ALL the GM cams determined that the second style LS1/LQ9 cam was the best overall for the lower compression 5.3....L33 might be a different story as it has the larger valved 243 heads and 10 to one compression.
The LS1 cam lost ZERO ft./lbs. of torque at 2500 and only continued to gain from there on up. Sure some of the other cams gained at 5500 and 6500 however the engine is still so much slower through the rpms just to get to the point where it's making more power....doesn't make sense to me to substitute rpms for cylinder pressure. Torque is what moves weight.

Mercier

iTrader: (15)

Great points. I hadn't even considered compression or head differences and I'm far from an expert on those subjects anyway. OP says already purchased the LS2 cam and I think that factored in a bit. I doubt much was paid for it but I don't know what budget is either.

I was impressed by the LS1 cam when I read that article myself. So much so that I have one(2000 Vette) I originally bought for that exact purpose but went bigger before I put it together. Been too lazy to post it for sale or the LM7 it was headed into.

What's your opinion in same situation but heads milled? My original plan was above cam and I have a set of basically new 853s I was going to steal the valves/springs from, throw those in the 862s milled .030 or so and call it a nice budget 5.3. I priced the milling and opening of the valve seat at about $50/head locally.

So since I wasn't the first one to bring it up, OP(if you are still listening) if you want said cam or other stuff PM me with your zip code and we can work something out. No front cover or sensor issues either. I have the cam, springs, retainers, pushrods from a 40K mile car. I've flirted with selling it before but actually have pictures now.

I also have a clean LS7 cam in the way if you want to test out your rod bolts.