black_z

iTrader: (4)

That is my only real concern too, the secondary pushrod just looks like its going to be a big weak link to me. Im by no mean an expert though.

granitemonkey

Very Interesting point.

JL ws-6

iTrader: (50)

I'm not engineer either, but I do know a thing or 2 about a motor, and what I am thinking is that ohv or multi valve motors are usually designed to get more air flow with smaller valves, which in turn results in a lighter valvetrain, and the ability to go to higher rpm's. Look at the dohc 4.6 motor of Ford's(am not a ford lover, so don't think that I am with this statement), the power of that motor is all in the upper rpm range,which is possible because fo a lighter valvetrain, hence why guys spin that motor over 6800 on a normal basis and is why it is good for supercharged street applications. With the weight of the valvetrain on this new vette/judge motor, I am really wondering what's going on. Also, with the cam spec on that judge motor, the exhaust is gonna have to be ope alot longer to make up for the added volume that is going in due to the dual intake valves. Look at it like this, a set of ehads that flow 320 cfm in and 240 out make way more power with a cam that has a longer exhaust duration. That's probably why the cam split is the way that it is.

pman

iTrader: (6)

I'll let him know next time he stops by the shop

Z06Cam

You should apply for an engineering job in GM's powerplant division, since you obviously know a lot more than they do!

rons 00z

iTrader: (10)

the four valve heads i know about uses one push rod to push the two intake and exhaust. sweet deal if you ask me

Another_User

rons 00z

iTrader: (10)

will the mass of that bar really make a diffrence? is it hollow that would make a diffrence as well. just curious do you think the sts turbo kit is crap as well?

Another_User

:::bored of this conversation::: We will see how those heads work out.

Z06Cam

That's kind of what it boils down to, isn't it. The heads aren't out yet, so it's a little early to call them crap.

FAST LS1

iTrader: (2)

Like someone else said since there are 2 intake valves they will be lighter than one large intake valve, meaning the spring pressures will be lower on the 2 intake valves as opposed to the one large intake valve. The setup shown in the picture looks like it will support regular spring upgrades like the current LS1-6 can. For hardcore people who will want to run huge .600+ cams they'll probably have to upgrade to a future aftermarket rocker system like the current Jessel etc. I'm sure the aftermarket will jump all over the rocker system as soon as the 3V heads come out.

I see the 3 vavle heads as the next big step for OHC engines. Just like the LS1-6 were a huge step forward, the 3V will be an equally huge step forward. The only possible problem I see is port velocity at low lift levels, but with 6.0L being the smallest LS2 based engine, even large ports shouldn't be a problem on an engine that large. The increased hp picked up in the mid-upper rpm range will more than outweigh any low down hit the larger port area causes. The Dodge boys probably thought they had the upper hand in the OHV engine market with their Hemi, but I'd be willing to bet this design will top the Hemi's pretty easily. GM has the best powertrain development of the big 3, I have faith they can make it work better than anyone else could.

Z06Cam

Here is what someone on another forum had to say about the 2V vs 3V debate:
This doesn't sound like it's necessarily true, but I don't claim to be an expert. If he is right, can anyone explain this to me?

Another_User

The point (which GM forgot) is that at low RPMs you want to keep air velocity up, so you only run 1 valve. The then you open the other valve (hmmm...maybe they should have used DOHC) after certain conditions are met. This allows for improved low-mid range torque, and increased horsepower.

It's kind of like what has been done on engines in the past where you have an additional throttle blade that opens up allowing more air in, except only at later RPMs, except you are doing it in the head.

Z06Cam

Doesn't air flow faster through a smaller valve than it does through a larger one?

If this is the case, to what RPM (ballpark) would a head with 1 intake valve have an advantage over one with 2 intake valves? For example, if the only advantage is below 2K RPMs, who cares? It's not like we're going to use our Corvette to tow a trailer.

Like the LT5, right? The guy I quoted earlier did mention that.

Another_User

It depends on how much power you want to make, and where you want it. The kind of power it would make would be power you would feel on the street. That's what you want to sell. It would be particularly benificial in four-cylinders, or other "torque-challenged" cars.