A little background first ... 2003 RCSB 5.3. The jest of the mods were headers, exhaust, 6.0 heads w/ valve job, 216/220 114, RADIX, trans work, 4.10's and stickys. That netted me 11.95 @ 110.79 with a 1.598 60'. An 11 second timeslip was always my goal with the truck and the blower. Once that was done, I wanted to go back and do it all motor.

I took the blower off, changed cams, and put the stock heads back on. The cam that went in was a 233/239 597/603 113, in a STOCK 5.3. Very poorly tuned it ran a 13.7 @ 101. This is shifting at 7000 hitting some valve float (I assume) at 6200.

On to the cam ... at first, drivability was a bit rough. Once I started taking some time to tune it, it wasn't bad at all. It was a bit of a slouch down low poorly tuned. With the CalTracs and the really wide tires in the back, I can turn them, but it takes some work to do get them up in smoke. Before tuning, it wouldn't do it at all. The cam really comes in at about 4500 and is still pulling hard through the valve float to 7000.

I've had some questions about my setup via PM and wanted to clear some things up. If I were to do it again, I would have done about the same thing. I like the monster cam despite it's drivability issues which with the time spent tuning have become minimal to say the least. It does need more compression however, and could use a much better head than the stock 5.3 head. I'm a little leary of shaving the heads with the size of that cam though.

 

I know I was a big critic of you using this camshaft
but, I'm still interested none the less. Hope you don't
mind but, I wanted to ask a few questions.

What 60' did you cut w/ the 13.7 @ 101?
Nice mph

Any chance of you getting to a dyno?
I'd like to see upper rpm behavior.

Stock rockers? What do you think is
causing the valve float?

Any chance you'll go back out after being tuned?

Thanks you for any additional info.

 

I would also like to know the 60' times. You are giving up so much down low with the cam there might be some room for improvement at the expense of some top.
The "float" might be in the stock valvetrain. How much did you retain? The pushrods are pretty flexy and combined with the high lift might be causing some harmonics. Going to a larger intake valve may not get the desired results with the smaller cylinders ( shielding ). Shaving is an option but maybe a thinner gasket for now? At least you could experiment and have a backout option.
You gonna stick with the 5.3 to the end? It will be quite a project but at least you have a goal in mind!

 

Ultimately, bigger motor ... for the time being, the 5.3 will have to work. I know I'm loosing a lot in the low end. I think going back to a 60e as oppose to the 80e in there now would help a LOT. I would go with something around a 3500 - 4000 converter, what ever would be more cost effective. The low gear of the 60 would be very helpful in my truck. I think I would be well into the 12's with that.

I do plan on going back, but I don't know what it will happen. I'd like to at least get some stiffer springs (the problem with the valve float) before I head back, but prolly won't. I do have hardened push rods, that's not the problem.

The 60' was a hair over 2.0. Did I mention it REALLY comes alive at 4500? The good thing is once it gets above there, 1-2 shift drops to about 5400, 2-3 drops to 5800. Keep in mind I'm shifting at 7000.

The cam has a very very nasty sound at idle too. It gets looots of looks, stares and glares rolling through a parking lot.

 

I also wanted to mention, I'm sitting at 38* timing WOT, no knock and could easily get more out of it, but don't think it would help any. Dyno is doubtful, I'm not paying 100 bucks for it. I may go talk to the shop owner about doing some tuning for him, dunno how much interest he'll see in my truck though, maybe enough to want to dyno it.

 

Man, that cam sounds and performs great! I would have pooh-poohed it too from the numbers but hey, if it makes you smile then it's worth it.
I forgot about the tranny, a 60E and nice stall will overcome the cam and drivetrain loss quite nicely. Most shops around here have no interest in playing with the 5.3/4.8 motors but IMHO should with the sheer number of them rolling around...
Glad you have a "new" toy to play with, keep us informed!

 

First of all where have you been?

Second are you going to take it all out on the 5.3 or are you going to ditch it soon for a 6L?

Third what is next in the build-up?

Fourth can you get a sound clip up of the exhaust?

 

I've had some personal things come up. Several situations actually. I've had my time devoted elsewhere. I've been doing a lot of driving back and forth roughly an hour one way, thus the perfect time for some tuning.

I'll take the 5.3 as far as it will let me go. I'm leary of sinking some money on a good set of heads for the possibilty of the motor letting go and ruinning a good set of heads.

I'll prolly try some used heads or something, with bumped compression, 60e and a converter, long term, maybe a new motor all together and some damn nice heads.

Sound clip will be a little difficult right now. I'm putting some rod bearings in it at the moment, and a some ARP rod bolts. I thought I heard something in the bottom end and didn't want to take any chances. I'm guessing I'll get them all changed and not find anything wrong though. I think it's as much very very passed due an oil change as it is the conditions.

I think the 5.3 has more potential than some give it credit for. It did run an 11 without any nitrous. There's been another one that has run an 11 spraying the **** out of it.

 

BTW .. I think it might be of interest to kwo that the cam's idling at 600 rpm.

 

Thats one big cam for 5.3, Nice too see you around again. What stall do you use?