5th Gen Z28, Gen V Engine.

[thePill]

continued....

If the valve angle is decrease a little more from the LS7's 12 degrees (say 8 degrees) and the valves are kept very close to the LS7's 2.20/1.60 valve diameter, the airflow could see increases around 20%. The LS7's heads were at least a 25% increase over the old LS2 (15 degrees) and the LS3 received similar increases. Some cam involvement contributed to those gains, the old LS2 had a .525 lift for example where the LS7 has a huge .591 on both the intake and exhaust. With VVT or Cam in cam phasing, the oil capacity will be no less than 8 quarts. I expect the compression to be high, 11:1 to assist with emissions. I will keep searching the internet for anymore information but information is very limited and should remain that way until we get closer to the C7. I got extremely lucking finding the information and pictures as is... and I have been looking for almost 12 months.

[thePill]

VVT or Cam in Cam phasing:
Regular VVT in a single cam OHV application is limited to either the intake valve timing or exhaust valve timing. I just can't imagine the intake/exhaust valves being controlled by a single cam unless it is a VVT/VTEC combination. GM stated that this new Gen V V8 will use Cam in Cam phasing like the Dodge Viper which is another word for VVT. GM also stated that both the intake and exhaust valves would be controlled independently. This means one of three things:

1.) GM found a way to adjust the intake lobes independently from the exhaust lobes on a single cam. VVT on the exhaust for a longer burn and more horsepower and a VTEC secondary lobe for the intake for torque and horsepower under hard acceleration and regular fuel saving operation below 4500rpm. This sounds kind of complicated, that's a lot of responsibility for a single engine component. There will also be two separate VVT cam gears w/VVT oil pressure unit casting or, some very complicated camshaft nomenclature.

2.) Just break down and go full DOHC, the cost are down and the gains are huge, possibilities are limitless, and fuel economy/emissions are fantastic. This engine design will typically weigh 15-20lbs more.

3.) Create a Duel Under Head Cam design (I believe the prototype 3 valve LS7 used this). This engine design will weigh about 10-15lbs more, the heads would be slightly more compact than a DOHC. See picture below.


So, a Super complex, multi-lobe single cam VVT/VTEC, a DOHC or a Duel Under Head Cam (DUHC). This is exciting...

[thePill]

I found this little piece of info.

3 valve, DI, OHV patents are also owned by GM for a more conventional OHV design that might utilize the Mechadyne cam like the Viper is using. All the tech exists, and I am pretty sure is quite producable. More a matter of costs associated with producing such a design. Might end up similar in cost to a DOHC, but would have packaging and weight advantage probably if you used the Mechadyne cam and didn't do the dual cam thing. Really think one or 2 cam ohv could still be less cost than a dohc V8.

What were looking at in a "Super complex, multi-lobe single cam VVT/VTEC" monster cam is this cam below, by a company called Mechadyne International. The last Viper used the "Super cam" see below...

Our concentric camshafts enable dual-independent Variable Valve Timing or VVT on a single camshaft. Both the intake and exhaust centerline timings can be controlled to give optimum engine performance over the complete operating range. These cam assemblies form a key part of many of our VVA systems, but they are ideal for cam in block pushrod engines.
Our concentric camshafts are:

• In volume production. The new Dodge Viper engine uses a concentric cam.
• The best and most cost-effective solution for phasing adjacent cams on a single camshaft.
• Essential for Dual Independent cam phasing in cam-in-block engines.
• Used in our variable lift and duration system (VLD).

Video contributed by Dragoneye of the basic build and operation of the Cam in Cam (added 6 May 2011)

[10spokess]

Man that is just sick nasty man I want one now lol

[IamJacksCamaro]

Can't wait to see it in a Camaro.

[truth411]

Gen V V8s displacement, remain 5.3 and 6.2. Magazine and internet sites assume its 5.5 because its the displacement of the le-man V8. What they fail to realise is that max displacement allowed is 5.5 ltrs, if max displacement allowed was 7.0 then the le-man vette would have a 7.0 V8.

[wildpaws]

Originally Posted by truth411

Gen V V8s displacement, remain 5.3 and 6.2. Magazine and internet sites assume its 5.5 because its the displacement of the le-man V8. What they fail to realise is that max displacement allowed is 5.5 ltrs, if max displacement allowed was 7.0 then the le-man vette would have a 7.0 V8.

I don't think we'll really know what displacements the GenV V8s will be until Chevy/GM officially releases some details. At this point I think that it is all speculation.
Clyde

[b4z]

Not that this has anything to do with motor pictured above:
I've heard that some guys who do weekend road racing will put a LS7 in their GTO/Camaro/Corvette then take out the cam and put in a LS1 factory cam and end up with about 470hp and a lower redline.
Since road racing involves a lot of extended high rpm running the valvetrain takes a beating. By leaving the factory LS7 valvesprings, etc. and taking the rpms down by 500+ they get almost bulletproof reliability and still have the 460 torque that the 7.0L motor offers in it's original 505hp guise.

When it comes to ALMS and Grand Am racing the motors in the Corvettes are not that impressive. They are so choked down by the governing body that hp is less than what you can buy off the street.

[truth411]

Originally Posted by b4z

Not that this has anything to do with motor pictured above:
I've heard that some guys who do weekend road racing will put a LS7 in their GTO/Camaro/Corvette then take out the cam and put in a LS1 factory cam and end up with about 470hp and a lower redline.
Since road racing involves a lot of extended high rpm running the valvetrain takes a beating. By leaving the factory LS7 valvesprings, etc. and taking the rpms down by 500+ they get almost bulletproof reliability and still have the 460 torque that the 7.0L motor offers in it's original 505hp guise.

When it comes to ALMS and Grand Am racing the motors in the Corvettes are not that impressive. They are so choked down by the governing body that hp is less than what you can buy off the street.

The LS7 is already bullet proof as is, way more reliable than the highly strungout italian/German motors and if something do go wrong waaaaaaay cheaper to fix to.

[thePill]

I'm going to attempt to explain this Cam in Cam operation. First, this CiC has nothing in common with VTEC, CiC does not alter the lift at all. VTEC was technically two cams in one, when a certain RPM was reached, a secondary lifter would lock into place on a secondary lobe that had a much higher lift. Honda's VTEC usually dropped its secondaries around 4500rpm, at which a higher lift was used only, duration could be altered depending on the secondary lobe and timing would remain the same.

Cam in Cam (CiC): This setup is made of two cams, a hollow exterior cam (hollow like a OHC's cam) and an internal solid cam. I don't know for sure but, the exterior cam would control all the intake valves and the internal cam would control the exhaust (could be the other way around). The VVT phaser (or the strange casting that surrounds the cam gear and adjust the cam timing) would contain two separate cam phasers for each cam. Probably a large outer phaser for the hollow exterior intake cam and an inner phaser for the small internal exhaust cam. Controlled either electrically or by oil pressure, it would adjust the intake and exhaust separately. You will notice the small pins in the cam itself, these pins would disengage the internal exhaust cam from the exterior cam by pushing the pin outward so that it can operate and adjust independently. The normal operation position of the pin would be "IN" and oil pressure or electronically (doubt it) would force the pin "OUT" so that the internal cam could spin independently from the exterior cam. Maybe oil pressure that is bled from the VVT phaser into the internal cam tube disengages the cam pin (pushes it up), I don't know for sure... I would have to whip up a few more diagrams before I could say for certain if bleed over could produce enough oil pressure to do that.

As the CiC operates independently, and the engine returns to normal operation, the lack of oil pressure inside the internal cam tube would allow the cam pin to return to the :IN" position, locking the cams together again for normal operation.

I hope this explanation is easy to follow...

[LOWDOWN]

RE: Gen-5 architecture:

The only "sacred cow", here, are the bore centers @ 4.40". Changing those makes retooling/manufacturing much more expen$ive, and instantly obsoletes ALL that the previous Gen SBCs are/were based on.

That is where the limiting factor for "bore" comes in. You cast the blocks with 4.40 centers, and sleeve down from there.

Valve sizes: you don't build a 4.00" bore engine with 2.20"/1.60"+ valves..."shrouding" happens. Take a look at LS1/LS6 engines: smallish bore = smallish valves. Pretty much max'd @ 2.05".

Valve sizes, alone, do NOT correlate to greater revs. In fact, a smaller valve weighs less, and theoretically can be rev'd higher... That's part of the reason that a 4-valve engine revs higher than an equivalent 2-valve.

Port dimensions and shapes are important to high revs. Bottlenecks in the ports restricts your usable rev capabilities... More air in/exhaust out = more power-better emissions, again depending on port design, and combustion chamber shapes. Port velocity is more important than all-out port size.

Raised cam, as seen in the Ilmor/Chev cum Mercedes Indy engine, = shorter pushrods = less valvetrain weight = higher rev capabilities. NASCAR engines utilize flat-tappet cams, much less efficient than rollers, and still achieve 9,000+ rpm for hours on end. Almost impossible to do with current production-based long pushrods...

With DI, optimized bore and stroke per displacement, and optimized cylinder head design, combined with short pushrods and VVT, these engines regardless of displacement will offer power-to-size with emissions AND economy previously only dreamed about...

[PYROLYSIS]

Originally Posted by thePill

I hope this explanation is easy to follow...

Well, you tried. I really have learned a lot from your thread, it's just that the average enthusiast,(like me), don't have a real understanding of how all of the basic parts of an internal combustion engine work. Some of this stuff is over my head,(for now), but is still a great read. Thanks for sharing. I hope you're just not a really smart Mustang fan trying to throw us all off, cause right now I wouldn't be able to tell the difference.

[Blizzard]

Originally Posted by thePill

Here is a picture taken of the new Gen V 5.5 liter C6R engine. I am pretty excited because I have not seen the engine at all before this picture. This was taken last month by a GM fan.

I will dig up some stats and what I know so far. Just real quick though, this engine produces 470hp and currently is a 5.5 liter. This is the engine I believe should go into the Z28.

I agree this is the motor we want in the Z28, but sadly I just dont see it making it into the Camaro until 2014 and in the new alpha platform.

[b4z]

My CiC kicked in YO!