CI DENALI

That's interesting. I wonder what they changed on the Phaser? Is the L94 rated at more HP? It should be, because the TB alone is probably worth at least 5-10HP, I would think. I'm kicking myself now for not buying an '09, because I took a really good deal on my '08 last December, thinking they were the same.
BTW: Does your truck have the 3.73 gear that people have been saying comes in the '09? If it does, you should have a real animal on your hands!
It would be really good if you could do a base run with the stock cam and then after to see what difference it makes. Good luck with the install. Looking forward to hear how it goes...

Just Enough

The 09 phaser took away about 10 crank degrees of possible cam retard, it really doesn't change anything because none of the trucks use anywhere near that amount of retard available. Max redline performance retard should be around 8 to 12 degrees depending on how much advance the cam has ground into it. The max I saw in my table was light throttle cruise of 26 degrees of retard. That whole island of cam retard in the light throttle region is emission related and it gives the truck a squishy press the pedal and nothing happens feeling. It has been said that the retard island is efficiency based to minimize pumping losses, I don't buy that theory. Delete the retard island and your truck will drive better. The cam should stay fully advanced until around 4000 rpm, then progressively retard until redline.
Yes I have 3.73s, feels great out of the hole and still loafs on the freeway with the 6 speed.

CI DENALI

Thanks for the info, Bro. I always wondered why the hell we would need like 40 degrees of retard, since I couldn't see how that would help with fuel efficiency, even at light pedal/ light-load conditions. I think the VVT is a great thing, but it must be that 8-10 degrees either way would be the max that you would need 95% of the time. It seems that it was a bit of trial and error for GM too, since they've now taken out some of the retard. Also, the smaller the range the more lift you can use without the risk of a valve kissing a piston, so that would be an additional benefit from limiting the range, since the biggest cam Comp offers is still less than .580" lift, and our heads keep gaining in flow up to about .630"ish. I'll bet in a year or so we're going to see some real power making cams with this VVT.
I'm wondering what kind of advance/retard Comp grinds into their cams to get the right range for each? Probably varies for each grind depending on the duration. One thing that pisses me off is that they don't package the Phaser kit with the cam. Jegs has the cam and springs (918) I want, but not the Phaser tool, so that sucks. It may be that you don't need the phaser limiter with a smaller grind in the '09 though, from what you're saying?
I'm seriously considering doing 4.10's especially since the max speed limit down here is 50MPH. I'm not even sure if my truck shifts into 6th gear at all! I know that we've digressed from the topic of this thread, but these things do happen when you start discussing valvetrain!
Maybe you should do a new thread on the L94 though, because it's really interesting to see how these engines are evolving.

Just Enough

As long as the original poster doesn't mind we can keep this thread alive since anyone messin with their L92/94 will probably read some of this. The 4 cams Comp offers are ranged to the maximum duration you can use with the stock pistons. The pistons have an exhaust valve relief but not an intake relief, so without an intake valve relief the intake valve with any additional duration will chase the piston and catch it. An aftermarket forged piston with the proper reliefs will allow more extreme cams. The phaser limiter kit is primarily designed to limit the phaser when the engine performs it's self diagnostic BS and ranges the cam through it's full retard to make sure everything is working. The ECM is only looking for a range of motion which is still remaining with the limiter in place, but it shoves the phaser to it's limits in both directions. This is not a problem with the stock cam obviously, but as soon as you add lift and duration you need to limit this range.
I personally would not run a single valve spring in my engine when Patriot golds are so inexpensive and reliable. I know a lot of folks have had success with 918s and the new 918s and the newer 918s, but a failed single spring drops the valve into the cylinder destroying the motor, a failed dual spring kisses the piston and bends the valve necessitating a valve job not a motor. Another LS scenario is a failed rocker needle bearing lets the rocker knock the spring hat down allowing the keepers to jump off the valve stem dropping the valve into the cylinder. Harland Sharp modifies all LS rockers to prevent this for around $250, it is mostly a problem in 2007 LS7s. I hope the LS3/L92 is not prone to this. PM me with an e-mail address for further info you requested.

CI DENALI

Ok, that makes a lot of sense. I think that when we start to see guys with dual valve reliefs on the pistons, we will really be able to see the benefits of VVT.
I also wondered how it is that MAST Performance, for example, sells a couple of relatively big VVT cams, seemingly without the Phaser limiter. My guess is that they must be limiting the phaser by programmimg the ECU, so that the valves don't kiss the piston. I like the idea of a physical stop, though.
I know what you mean about the dual vs. single valve springs. The beehive is lauded by just about everyone because it has a higher valve float limit than a conventional straight spring, all other things (like spring rate) being equal and so you can use the beehive for with less valvetrain stress. However, I have had an experience in the past with the Comp Pacalloy 1.25" SBC springs (about 12 years ago) where they seemed to reach a point where they all started breaking one after the other after about a year of street/strip use, and if it wasn't for the damper, I would've needed a rebuild. The problem is that the beehives don't have the damper because of their shape, so your point is well taken. I have a couple of friends with C5's who have been using the Patriot springs for years with good results, so I'm gonna go that route I think. Thanks again for all the info.
BTW:Are you saying that Harland Sharp makes a rocker for the LS3/L92/4? I asked the Harland Sharp guy at Bradenton last weekend, but he couldn't tell me whether they did!

Just Enough

MAST does or will include a phaser limiter I just don't think they have it on their site. The diagnostic sweep is only one potential crash scenario for the phaser + longer duration cam, the other is a very momentary loss of oil pressure.

SLP sells roller rockers for the LS3 family and they look very much like Harland Sharp products.

The primary touted advantage of the Beehive spring was a reduction of harmonics in the 5500 to 7000 rpm range. The spring can get a standing wave in it at a given rpm which will pull it's ability to return fully leaving the valve to float a tiny bit, not causing a crash but causing a reduction in compression which is a very obvious spike drop in torque. The motor will pull through this harmonic but looking at the dyno graph the valve float can be seen. Roger Vinci brought this to my attention several years ago when I was picking his brain about valve springs. You have got to think an additional advantage is only having to produce, stock and install only one spring instead of two for the typical micro savings OEMs are famous for chasing. I wish I could have more confidence in the Beehive, because it also reduces the mass of the hat. If you are looking for some interesting videos on you tube type in valve float, it will make you glad your valve covers aren't transparent when your redlining your engine.

CI DENALI

I hear you about the micro savings BS - it's what helping to kill Detroit, IMO. I remember reading in an Engine Masters mag a couple of years ago that GM spent millions researching he benefits of the beehive spring, which, according to that article, was money well spent, because of the so-called advantages of increased valve float with a lighter spring pressure. Truth be told, the real advantage is probably the lighter retainer.
It's like the hydrualic vs. solid roller argument - I'm sick of hearing the old wives tales about solid rollers needing constant lash adjustment when in fact if you have properly tightened poly locks, that's a myth, since a roller cam doesn't wear like the old flat tappet cams did. Then there's the argument that a solid roller cam is "smaller" than a hydraulic roller with the same specs. This is just BS since we all compare cams at .050" lift these days and I have yet to see a solid with that much lash! The truth is that in any performance application a solid will outpower a hydraulic cam with the same specs and when properly adjusted is just as maintenance free - it just takes a little more time to set the valves initially and requires an adjustable rocker(something the factory couldn't possibly contemplate). As for he noise of the solid tappets, well, from my experience, they're not much noisier than the factory hydraulic roller lifters in all of the LS motors, IMHO.
A solid roller would significantly increase the RPM threshold of these motors (once the bottom-end is built to handle it, obviously)
BTW: If you haven't seen them already, Mast also sells some very nice looking adjustable rockers for our motors in both 1.7 and 1.8 ratios.
In the final analysis, my theory is that with adjustable valve train (like Jesels) and a big solid cam, good springs, a properly working phaser and some fly-cut pistons, these motors will make some serious mid and high RPM power without a significant loss of low end.

Just Enough

You are totally correct about the solid roller lifters they have a huge weight advantage over hydraulics. They would be an asset to any high performance motor and really would not require maintenance intervals any closer than 15k miles. There are still a fair number on new current cars on the road with solids or cam on shimmed buckets. I think that Detroit is allergic to solid lifters and they feel that the longest possible service interval is the primary focus of the customer. I can remember the permanent antifreeze coolant era in the 80s.
What's kind of peaking my interest now is whether a phaser can be fitted on an LS7. I need to figure how the phaser is controlled. I know that a magnet in the timing cover is energized to to open the cam blot/valve to control the phaser. What I don't know is, is that magnet pulse width modulated to pulse the valve open and closed at intervals corresponding to the necessary oil flow volume to control the degree of retard? There are in between values that the phaser can stay at, so some how this can be controlled.

CI DENALI

According to the GM High Tech article, pulse width modulation controls the phasing, so it seems that your thinking is right on this. I'm guessing that since the phaser defaults to full advance when oil flow is cut off, and since you pretty much have full oil press in these engines from a relatively low RPM, the ECU is programmed to pulse the phaser solenoid/bolt as RPM increases and the programming takes account of the fact that max oil press is acheived long before the cam starts to retard (or needs full retard) at high rpms.
In other words, oil press might not be a factor at all. I had a struggle with this train of thought the other day when I was changing my oil - what affect does oil viscosty have on the VVT phaser, since higher viscosity oil can sometimes bump up the oil pressure.
You have the same idea as me about the LS7 w/ VVT and I'm thinking that since the necessary oil for the phaser comes from the cam journal and the phaser assembly is all external bolt on stuff, it should in theory work on an LS7, but, as far as I know, no one has done this. Even Mast, who are probably the pioneers of modified VVT motors, don't have VVT with the LS7 or LSX blocks, a least from what they have on their site.
What would be interesting as well would be a series of dyno tests of some VVT cams vs. non VVT cams with the same specs on say, a 427 L92, so we could really see how much the VVT is really worth.

Just Enough

Comp posted a dyno chart of their currently biggest #403 L92 VVT cam, and it held peak HP for 1200 rpms from 5800 to 6500 dead flat, hp not torque. I have never seen hp flat up there for that long, I think that is what the value of VVT is. I just need to get my little cam in this week and feel this first hand.