NorCalAnthony

Hey Martin, do you mind sharing the specs on that towing cam you're wanting to try out? I'm also planning on swapping a set of milled 243's and a NNBS intake on the 5.3 I'm putting in to my K5 and was curious what one of our resident cam masters would do in the same situation...

GENIIIDude

http://www.magnusonproducts.com/p-49...ercharger.aspx

And forget about it!

Tuskyz28

that'll be an awesome idea!! Honestly tho if I had 5500 bucks I'll go buy a 408ci short block and slap on the factory heads 243/799/317/823 and cam it appropriately for towing. By a motor having a 4.000" inch stroke it'll definitely have a mean low end grunt and we won't have ever to worry about boost levels and intercoolers.....

Richard Holdener showed just how effective a stroker crank can be.
A little copy and paste here.... The only stock stick we had at our disposal was from a 2004 5.3L LM7. The mildest of the LS bunch, the LM7 cam offered a .466/.457-inch lift split, a 190/191-degree duration split and 114-degree LSA. Using the Holley Dominator system, Westech's Ernie Mena had the stroker combination up and running in record time, and the stock-cammed 408 eventually produced 449hp at 5,100 rpm and 522 lb-ft of torque at 3,900rpm. Obviously the mild stock cam was limiting top-end power, but the 408 still managed to exceed 500 lb-ft of torque from 3,500 rpm to 4,600 rpm.

Sales@Tick

iTrader: (3)

Gentleman I talked to that added a Maggie 112 to his 5.3 said he got about 6-7 mpg while towing a 5k-6k load. He did say it had a ton of power, but that it sucked down gas.

I'm sure you could experiment with leaning out the fuel mixture, but at such a high load towing a trailer that weighs that much I don't know how comfortable I'd be leaning it out a lot. At least enough to make a noticeable dent in fuel economy.

A would imagine that a small GT-30 Garrett turbo with a .60-.70 exhaust housing would be where it's at for towing AND MPG.

96capricemgr

iTrader: (1)

Be a LOT more interesting and informative if they tested the 5.3l with the same heads and intake to compare.

Tuskyz28

Caprice, you mean a stock cube 5.3 or a stroker 5.3 (383ci) motor? That 408ci would get up to the on ramp fast pulling a car with 500 ft lbs. That's great torque

96capricemgr

iTrader: (1)

No I mean a 5.3l with that intake, heads and injection.

Tuskyz28

Well well well...... I damn near got you covered too.....

check it out as Richard does the best comparisons ever and give his real honest opinion

http://www.truckinweb.com/tech/1208tr_5_3l_bow_tie_builds_mild_to_wild/

Bowtie316

iTrader: (1)

Just some thoughts to ponder.

I would definately swap out the heads to aluminum 317s at the very minimum. I usually get flamed for suggesting this, but for the intended purpose, I believe some LS1 heads (241/853) would barely raise the compression ratio, but with the smaller runners and 2" valves would really help out the torque in the range that this motor operates. Being aluminum it would basically offset the increase in compression ratio. I have this theory that the reason these 6.0s need 2500 rpm to make any power is because the intake ports are huge.

Definatly don't swap intake to the NNBS, the intake you have is the best one available for low end torque.

Also, I would consider upgrading the PCM to a newer operating system 01-02, it has a better knock retard ability and on my swaps, I found it to have less "ghost" knock retard.

I run a comp 206/212 @114 cam in my s10 with a 5.3. It has stock converter 4L60e and 3.08 gears and that thing has great torque off idle. This cam in a 6.0 would be a huge improvement over stock and I don't think it would really give anything up anywhere.

Tuskyz28

Well let's take that 206 cam..... to be honest I love that cam!! Looks like a solid performer. Let me work my little copy and paste magic from a motor Richard Holdener built and tested.


The 6.0L stroker was first run with a stock LM7 (5.3L) cam to establish a baseline. Equipped with the stock LM7 cam, the AFR-headed 408 stroke produced 449 horsepower at 5,100 rpm and 522 lb-ft of torque at 3,900 rpm.

The first Crane cam tested on the 408 offered .500 lift, a 206/214-degree duration split and 114-degree LSA. Despite being the mildest of the bunch, the 206 cam improved the power numbers to 515 hp at 5,400 rpm and 556 lb-ft at 4,600 rpm. The mildest cam improved the power output by 65 hp.


The torque curves really tell the story lower in the rev range. Note that the 206 cam bettered the LM7 cam through the entire rev range (from 2,700 rpm to 6,000 rpm). The wilder 224 cam basically matched the power of the stock cam up to 3,800 rpm then pulled away dramatically there after. The 240 cam actually lost power up to 4,100 rpm, but stormed away to the tune of nearly 200 lb-ft at 6,000 rpm.

I'll say paying very much attention to detail is key!!

Mercier

iTrader: (15)

What about 1000-2500RPM? Seems like that is more important in a tow application and nobody has numbers in that range. I imagine the stock cam(s) embarrass the larger cams in that realm.

Tuskyz28

Good question!! Richard graph doesn't show that low in rpm range. However if you look at the graph the 206 cam is way higher up even way down low...... I'm go say that 206 cam would be sweet and even better way down there do it being designed by Crane for towing applications and designed to be very easy on springs, pushrods etc..

Bowtie316

iTrader: (1)

Two more things to consider.... the factory 4L80E converter, coupled with high gears and a heavy vehicle actually stalls fairly high, like close to 2000 rpm. I highly doubt a 206/212 cam in a 6.0 would do anything but gain torque above 1500 rpm over a stock cam.

The second is, the 99-00 6.0s had an even smaller cam (191/190 and .457/.466) than the 01+ 6.0s had (196/207 and .467/.479) so the gains should be even better for the OP.

Tuskyz28

Hmmmmm..... Roger Vinci says other wise.... not sure if you ever heard of him but he the big cam guru over there on performance trucks..

anyway he got a interesting line of cams~ hd tow stick, ultra torque, butt kicker, the trucker, chopper just to name a few. Each cam he designed has a different purpose.....

Bowtie316

iTrader: (1)

Yeah, I've certainly heard of the vinci line, what part doesn't he agree with?

96capricemgr

iTrader: (1)

What head castings and intake PN used on each etc. I like to try to compare things in detail, not just blindly link things that I think support the opinion I already developed.

If a 5.3l is tested with 706s and a 408 tested with 799s how much of the difference is in the heads vs. displacement?

Tuskyz28

well that's a great comparison but hard to answer cause the was cammed totally differently.... The 408 was first tested with 317 heads then a L92 head then a afr head. The 5.3 on the other hand ran 706 heads then tfs heads bolted on then later stroked to a 383ci........

The 408 also was tested with a car type intake manifold while the 5.3 was tested with a truck type intake.

After all we would be comparing a apple to a orange.

CattleAc

iTrader: (7)

Well...I think we have a plan... finally got a chance to call Martin on Fri afternoon. He was extremely helpful with my questions, and took his time to explain some of the valve events I was a little unsure about...I can't imagine how incredibly busy he is, yet he took all the time he needed to help me.

(He also said he got his truck purchased...I can't wait to see what he does with it.)


Thanks to all who responded...I really appreciate any and all of the helpful advice.

dr_whigham

iTrader: (49)

Just sent you a PM for a friend needing this!!