5th Gen Z28, Gen V Engine.

[thePill]

Originally Posted by LOWDOWN

A .591" lift cam in a 427" is no problem. A .591" lift cam in a 376" (or less) is extreme. I built a 346" LS6 with LPE's GT1-1 cam....631" lift...that idled like Jason Line's Pro Stock...and wasn't even close on emissions. Big-ass cams need big-ass cubes, on the street...VVT or NO VVT...

As for a Z/28 coming from Oshawa with a "race engine" in it, "I don't think so, Tim..." Emissions-compliant, and CAFE-friendly, my friend.

Yeah, I agree... A no go for the big lift. That is why it would be imperative that large valves are to be used on a high RPM, 2 valve OHV. I only suggested lft and duration would be helpful if the chambers got too cramped. We found that there is slightly more wiggle room in a 2.20/1.61...

[thePill]

Originally Posted by LOWDOWN

A .591" lift cam in a 427" is no problem.

Do you suggest a .525 lift? What lift would you feel comfortable with in a 350? I feel pretty good about the 2.20i/1.61e valves and with that we wouldn't need the LS7's .591 intake/exhaust lift. I don't think we would need the LS7's duration either. The LS7 uses a 230/211 duration on the intake/exhaust.

Edit: Although my sources may be incorrect, I have heard that the Gen V head carries a 2.18i and 1.60e valves (as I previously posted). According to your inject about the optimal valve size vs. bore, I can only see a 4.00 to 4.125 stroke regardless of the valve angle.

[thePill]

Road Racing: If this is how Team Corvette does it in ALMS GT2, Team Camaro should be doing this in Grand Am GS.



Notice Russ O'Blenes face when he talks about the pair of 28.8 millimeter air restrictors ALMS requires them to use (2:28 in video), He reminds me of Chris Farley at that moment. That same pain is felt be Stevenson Motorsports & Mitchum Motorsports in Grand Am (As well as your Mustang brothers upon request by BMW).

[Blizzard]

Originally Posted by thePill

Sorry for the late reply, I was locked into a technical discussion but, I think the time frame that most insist on is correct. I believe GM said that the C7 would be out in model year 2013, so calendar year 2012 is when we will see both the C7 and the Gen V engine at shows. Camaro fans should be praying for GM to break the usual route, as in Corvette/Camaro leap frog. A simultaneous C7/Z28 release would really draw some attention in the summer of 2012. Will GM break tradition? This would be the first time (that I know of) that GM played both aces.

I would love for them to bring both out at the same time, but not sure they ever will because of tradition an the fact that they would have to pay for all the safety testing for a a car that may only last 2 more years in the current generation.

Now there seems to be a sign that I am wrong. With the announcement of the FE4 package for the SS we could be looking at a predecessor. There have been other screw ups by GM giving hints about a Z28, there was a video with a display board in the background that said the SSX wheels came from Z28 blanks and Leno stating that his car could be a future Z28 design. So we will see but that ZL1 sure looks nice and so does the new synergy series.

[thePill]

Originally Posted by Blizzard

I would love for them to bring both out at the same time, but not sure they ever will because of tradition an the fact that they would have to pay for all the safety testing for a a car that may only last 2 more years in the current generation.

Now there seems to be a sign that I am wrong. With the announcement of the FE4 package for the SS we could be looking at a predecessor. There have been other screw ups by GM giving hints about a Z28, there was a video with a display board in the background that said the SSX wheels came from Z28 blanks and Leno stating that his car could be a future Z28 design. So we will see but that ZL1 sure looks nice and so does the new synergy series.

If we keep the tread here up, hopefully that gives Team Camaro enough pull to raise the issue with GM.

[Blizzard]

Originally Posted by thePill

If we keep the tread here up, hopefully that gives Team Camaro enough pull to raise the issue with GM.

I think the issue for team Camaro is the engine. there stuck unless GM breaks tradition and has a dual release of the Gen V V8, They know a V6 Z28 wont sell as good a V8, and the LS7 is about the only production engine left on the table and it would drive the cost to high.

[wildpaws]

Originally Posted by Blizzard

I think the issue for team Camaro is the engine. there stuck unless GM breaks tradition and has a dual release of the Gen V V8, They know a V6 Z28 wont sell as good a V8, and the LS7 is about the only production engine left on the table and it would drive the cost to high.

You have to remember that way back in '67, the Camaro got the new 350 engine the year before the Vette got it. I don't think it's likely to happen again, but it could.
Clyde

[SuperCarEnthusiast]

Very interesting development! I hope they put in this new engine. But it might be for the C7 Corvette as the first to get it since it was develop by the look of it for that purpose.

[Mr. Wyndham]

Originally Posted by 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...

I don't think the pins move...

Based on what I've read about the CamIncam technology (GM's version will undoubtedly vary if they use this concept):

There is a solid camshaft inside a hollow one.

In the outer, hollow shaft, you'll find slots that reveal the surface of the inner, solid camshaft.

The some cam lobes are pinned to the inner shaft through the slots in the outer shaft, and the outer lobes are pressed in place.

The cam phaser actually attaches to BOTH the inner and outer shaft, linking and spinning them together. This unit also modulates the degrees of advancement between the two shafts.

The pins never move, though, and while the two shafts can adjust separately there's no true independent freedom there, because otherwise that'd require the outer shaft to be cut in two to allow for the connection to the inner shaft - which isn't an option

Unless I read your post wrong, and I just repeated what you said.

Regardless, this is a great technology to think about...it'll help keep the engine light, compact, and relatively simple in operation/repair all while providing the benefits of a true VVT system to the alread super-efficient Small Block Chevy family!

[thePill]

Originally Posted by Dragoneye

I don't think the pins move...

Based on what I've read about the CamIncam technology (GM's version will undoubtedly vary if they use this concept):

There is a solid camshaft inside a hollow one.

In the outer, hollow shaft, you'll find slots that reveal the surface of the inner, solid camshaft.

The some cam lobes are pinned to the inner shaft through the slots in the outer shaft, and the outer lobes are pressed in place.

The cam phaser actually attaches to BOTH the inner and outer shaft, linking and spinning them together. This unit also modulates the degrees of advancement between the two shafts.

The pins never move, though, and while the two shafts can adjust separately there's no true independent freedom there, because otherwise that'd require the outer shaft to be cut in two to allow for the connection to the inner shaft - which isn't an option

Unless I read your post wrong, and I just repeated what you said.

Regardless, this is a great technology to think about...it'll help keep the engine light, compact, and relatively simple in operation/repair all while providing the benefits of a true VVT system to the alread super-efficient Small Block Chevy family!

There should be a "master pin" that stays engaged during normal operation and disengages to allow both internal and external cams to adjust independently. You will see this "master pin" on the cam photos I posted on the black ring on the cam. One picture it is in the "up" position and the other picture it is in the "down" position. There is still a lot to be learned from this technology... I know the cam itself is very complex.

Edit: It looks like there are multible master pins in the cam...

Edit #2:
If the shafts cannot adjust the intake and exhaust completely independently, then it would defeat the purpose having a complicated camshaft. Traditional VVT in a pushrod engine can only control either the exhaust or intake valves, this cam is intended to perform just as a TiVCT on a DOHC engine does. Without the ability to do so, it loses the flexibility that the DOHC engines have... like controlling over lap

[Mr. Wyndham]

I misspoke....they can adjust independently...but the pins don't move, based on what I've read.

When I said "independantly"...I was thinking of a full 360deg rotation relative to each other, which just isn't possible.

What I meant to say was, if the pins disengage, then there's no control over the cam lobes, since the pins travel THROUGH the outer shaft and connect to the inner shaft. Normal operation will see continuous adjustments, which is done by the cam phaser that attaches to and controls both the inner and outer camshafts separately.

I'm not sure what you mean by "master pin" versus a normal pin...

Anyways,

Check out this video from Mahle (the manufacturer of the Viper's CaminCam system), it's a FANTASTIC animation of the assembly and operation of this component.

Originally Posted by thePill

There should be a "master pin" that stays engaged during normal operation and disengages to allow both internal and external cams to adjust independently. You will see this "master pin" on the cam photos I posted on the black ring on the cam. One picture it is in the "up" position and the other picture it is in the "down" position. There is still a lot to be learned from this technology... I know the cam itself is very complex.

Edit: It looks like there are multible master pins in the cam...

Edit #2:
If the shafts cannot adjust the intake and exhaust completely independently, then it would defeat the purpose having a complicated camshaft. Traditional VVT in a pushrod engine can only control either the exhaust or intake valves, this cam is intended to perform just as a TiVCT on a DOHC engine does. Without the ability to do so, it loses the flexibility that the DOHC engines have... like controlling over lap

[thePill]

Originally Posted by Dragoneye

I misspoke....they can adjust independently...but the pins don't move, based on what I've read.

When I said "independantly"...I was thinking of a full 360deg rotation relative to each other, which just isn't possible.

What I meant to say was, if the pins disengage, then there's no control over the cam lobes, since the pins travel THROUGH the outer shaft and connect to the inner shaft. Normal operation will see continuous adjustments, which is done by the cam phaser that attaches to and controls both the inner and outer camshafts separately.

I'm not sure what you mean by "master pin" versus a normal pin...

Anyways,

Check out this video from Mahle (the manufacturer of the Viper's CaminCam system), it's a FANTASTIC animation of the assembly and operation of this component.

Ah, Ok, I see now, those "Master pins" (what I call them) connect the inner and outer tubes together. The holes in the outer tube allow the intake lobes to adjust independently. I was under the impression that the pins would disengage to allow the cams to operate independently, almost like VTEC in which the second cam becomes active at a certain point. I would love to see the phaser operation, it looks like there would have to be a two in one phaser design. I still remember reading about the pins disengaging but that might be a different design or I might be seeing things.

Anyway, great video... I suggest everybody who is interested in the Gen V engines watch it.

Edit: This video needs to be posted towards the front of the thread...

[shank0668]

I think the genV is a good motor for the Z28. But I think that when that motor starts getting used, they should use the 6.2 Gen V for the ZR1 ZL1 and CTS-V

[ShnOmac]

Insert "What Gen V engine" smiley here......