Gen IV SBC news!!

I don't know if this has been posted before but here goes.

The Gen 4 SBC is re3ally just a updated gen III. All gen 4 heads ect will bolt to the gen III Blocks. This months Chevy High Perormance has a pic of a gen IV SBC with three valve heads! This will be aswome in the hands of us rodders... 2 intake valves will mean much more flow potenial. I have seen LS6 castings that flow 330cfm at .500 lift. 700RWHP pump gas blown 6.0L Vettes, GTmonarO's, next Camaro ect..... Look out ford camp.

yea, there was a post about it before, i think it was from an article with the holden commodore or something
anyways, that would be nice to have 3 valve heads, and ford is already putting it in production in the year...2004-5 (?)

That's some big news I think....all those 98-02 LS1 guys looking for more air...3 valve heads! The sky is truly the limit! Throw a blower on there and you're through the roof!

The air flow potenial of a 3 valve big bore (4" or more) And the already awsome 15 degree valve angle will blow the small bore 5.4 mod motors away. Modern SBC gen III motors can easly be punched and stroked 427-430 cid and if you go with a C5-R block you can get 454cid. with the second intake valve controlled by a different rocker in a different location it seems you can slove the all rpm's and all tQ cam profile. Two different size intake valves with different ratio's means you can flatten out the power curve for low end grunt and high end power!!!! This could be awsome for hi power street cars.

It seems pretty odd.. more mechanical stuff.. it would be a less reliable engine.. I dont like it.. all they have to do is: make taller blocks for stroking capabilities and using the 11º valve angle used in the c5-r... or put more cubes in it with DoD

It's not really that much more "mechanical stuff". It would seem to be, but the two intake valves work off the same pushrod.

What happened to the variable valve timing I was hearing about if there's only going to be the one cam?

I wonder if we are going to see the 3v in production engines.

I liked those carbon fiber brakes as well.

So is there really even a "Gen IV Block"? Or is it really just new heads bolted to the same block to make a "Gen IV Motor"?

I thought it was just a 3 valve head made for emissions mostly.

will it still be called LS1, or will it have a different name?

Originally posted by Magnum Force
will it still be called LS1, or will it have a different name? The LS1 is nearing the end of its life and the 3v motor will most likely not be called that. Probably LS3 or 4 or something. The 5.7L motors are going to be phased out by the new 6.0L.

Good-bye 350! The end of an era........:( An engine born with the Camaro.

Hello to the 6.0L future!! :D








Disclaimer: I know the LS1 was technicaly 346ci, but 5.7L became synonymous with the 350.

The 350 has been dead for years. The LS1/LS6 are 348ci.

Originally posted by Chris 96 WS6
The 350 has been dead for years. The LS1/LS6 are 348ci.

Refer to disclaimer above and assumption given.

if this is all true, sounds pretty neat.. If things work out, we can get away with even more agressive cams on the street...

If it flows better at all points and works with DoD, then GM might as well start using the larger displacements on street cars for more power.. Imagine a 427 ci 550 hp "mild tune" LSx engine that still gets 30 mpg on the highway!

i don't see why the exhause ports are always neglected. sure there's less resistnace sucking in the air to THIS cylinder, but the next firing cylinder still does the same amount of work as before to push the exhaust out from the previous.

doesn't it seem reasonable that if you free up the intake you have to follow with the exhaust to get any real benifit? sure you suck in more air now, which means more power. but now you have more air to push out through the same opening as before which actually means MORE resistnace and more work to do than before, which should negate a good bit of that extra power gain.

does this make sense?

Originally posted by Chris 96 WS6
The 350 has been dead for years. The LS1/LS6 are 348ci. cough:346ci:cough

;)

I read this article in one of the Hi-po chev mags out there and the 3rd valve is used for better emissions only. No performace gains here ladies. Unless I'm wrong and retarded :rolleyes:

Nobody else answered it, but here's the short explanation for why the exhaust valves can be smaller:

Hot gases, such as those in the cylinder, have residual energy after forcing the piston down the bore, not much mass has been lost by combustion (very little), but they are occupying the same volume as they did previously, but at a much higher temperature and therefore pressure.

The difference in pressure between the exhaust manifold and the cylinder helps force the spent gases in the cylinder out, kind of like when you shake up a bottle of pop and open the top.

Because this difference in pressure is working in favor of the motor in this case, so the exhaust valve can be much smaller than the intake valve and still efficiently flow the exhaust gases out.

How can any mass be lost during combustion? (Or is this just taking into account blow-by?)

Originally posted by Chris 96 WS6
The 350 has been dead for years. The LS1/LS6 are 348ci.

Oh sorry...that's what I get for being a smart azz I guess :D

And I didn't even get it right myself. Consider me :Owned:

Originally posted by cmc
How can any mass be lost during combustion? (Or is this just taking into account blow-by?)

Someone correct me if I'm wrong...

I believe a small amout of mass is expended as it converts to kinetic energy.

Originally posted by Z284ever
Someone correct me if I'm wrong...

I believe a small amout of mass is expended as it converts to kinetic energy.

The stuff that's converted to heat (not directly to kinetic energy) is energy that was stored in the bonds of the hydrocarbon.

this thread has the potential to be moved to Advanced Tech :D

Originally posted by Z284ever
Someone correct me if I'm wrong...

I believe a small amout of mass is expended as it converts to kinetic energy.

Mass is not created nor destroyed. The hydrocarbons in the fuel, when ignited release energy in the form of heat increasing pressure. And thats what creates the kinetic energy.

Originally posted by 92RS shearn
Mass is not created nor destroyed. The hydrocarbons in the fuel, when ignited release energy in the form of heat increasing pressure. And thats what creates the kinetic energy.

Thanks, I was a recalcitrant organic chem student....I'm surprised anything stuck.

Originally posted by Chris 96 WS6
Oh sorry...that's what I get for being a smart azz I guess :D

And I didn't even get it right myself. Consider me :Owned:

Well, in the end you're right....I did stretch it a bit. ;)

THe 2005 Envoy and TrailBlazer Ext both will have DoD 5.3L V8s, now will these be Gen IV or GenIII V8s???:confused:

A small amount of mass (unmeasureable in terms of standard chemistry practices) is converted to energy during combustion.

If you look at things in an Einsteinian way, instead of Newtonian, it works.

"Mass is not created nor destroyed."

Depends on what you call "destroyed" or "created" as mass and energy are interchangeable.


In fusion or fission, a MUCH larger amount of mass is expended... i.e. turned into energy.

Originally posted by PacerX
A small amount of mass (unmeasureable in terms of standard chemistry practices) is converted to energy during combustion.

If you look at things in an Einsteinian way, instead of Newtonian, it works.

"Mass is not created nor destroyed."

Depends on what you call "destroyed" or "created" as mass and energy are interchangeable.


In fusion or fission, a MUCH larger amount of mass is expended... i.e. turned into energy.

This is correct, even though the amount of mass that is converted into energy via an internal combustion engine is only measurable on the atomic scale. And actually, mass can be created out of quantum flucuations of the space-time continum in the form of matter-antimatter particles. Isn't quatum theory grand? :)

Originally posted by DOOM Master
This is correct, even though the amount of mass that is converted into energy via an internal combustion engine is only measurable on the atomic scale. And actually, mass can be created out of quantum flucuations of the space-time continum in the form of matter-antimatter particles. Isn't quatum theory grand? :)

lol, yeah guys you are right though I think this goes a little outside the topic of the basic operation of an ICE.
I think that the newtonian theory is more than adequate for this. It is adequate for all of my thermodynamic classes and all of the related industires (Power generation, HVAC, Jet propulsion, etc.).

Originally posted by PacerX
Nobody else answered it, but here's the short explanation for why the exhaust valves can be smaller:

Hot gases, such as those in the cylinder, have residual energy after forcing the piston down the bore, not much mass has been lost by combustion (very little), but they are occupying the same volume as they did previously, but at a much higher temperature and therefore pressure.

The difference in pressure between the exhaust manifold and the cylinder helps force the spent gases in the cylinder out, kind of like when you shake up a bottle of pop and open the top.

Because this difference in pressure is working in favor of the motor in this case, so the exhaust valve can be much smaller than the intake valve and still efficiently flow the exhaust gases out.
hm. i can see that. but even with this effect if the exhaust ports are still larger or less resistive, it can only help move the air out. up to a point obviously.

Originally posted by 92RS shearn
lol, yeah guys you are right though I think this goes a little outside the topic of the basic operation of an ICE.
I think that the newtonian theory is more than adequate for this. It is adequate for all of my thermodynamic classes and all of the related industires (Power generation, HVAC, Jet propulsion, etc.).

True, in this case it's just a little footnote that doesn't need to be dealt with for all practical purposes. But I like to study quantum theory in my spare time, so I thought it would be fun to point out. Maybe one day, it will be important in our anti-gravity hovercars! :D

Depending on the application, a 3-valve head can outflow a 4-valve head.

3 valves can occupy up a combustion chamber head more efficiently than 4. Larger port area vs. port perimiter.

Honda uses 3 valve heads on most of their narrow-angle V motorcycle engines, engines that develope thier peak HP below 8000rpm.

Two large intake valves and one even larger exhaust valve, compared to two intakes and two smaller exhausts.

Plus, three valves can fit two spark plugs eiser than four valves.

And yes, emmisions can be lower.

Three valves sounds like a logical progresion for the Gen IV. Mercedes is using three valves now.

I wonder how much of the technology that was developed in the xv8 experimental engine that they built will be in the new gen 4 engines

http://www.gminsidenews.com/xv82.htm

Are they ever going to put this engine or the dual camshaft concept into production?