GM plans to transform small-block V8

[Road_Warrior]

Originally Posted by outback_ute

Surely the Gen III was new block and heads at the same time?

Third generation small block was a clean sheet design, yeah.

Also, I would take whatever Bob kLutz says with a pinch of crap.

[burnz]

Originally Posted by outback_ute

Are you sure? Not aware of any engines pre-1900 that didn't use pushrods.

otto engine 1876 i think, OHC
1912 for a 4V DOHC.

1949 oldsmobile OHV
not shure what year with the ford flathead tho.

[Bud Bud]

Originally Posted by burnz

otto engine 1876 i think, OHC
1912 for a 4V DOHC.

1949 oldsmobile OHV
not shure what year with the ford flathead tho.

Why do people think that overhead cams are recently new???

[Ryan]

Originally Posted by Bud Bud

Why do people think that overhead cams are recently new???

I guess, because alot of manufacturers didn't adopt it until later on.

[Wally]

Originally Posted by burnz

otto engine 1876 i think, OHC
1912 for a 4V DOHC.

1949 oldsmobile OHV
not shure what year with the ford flathead tho.

Wasn't the first production OHV by Buick in 1902? Before that, side valve engines were the go.

[Jeddak]

Over head cams? multi valve?
try 1929 with Deusenberg's 420cubic inch straight eight
twin-cam,4 valves per cylinder,and twin spark,
and if that's not enough ,this engine was available with supercharging as well

as King Solomon said "there is nothing new under the sun"( sorry Toyota ....not!)

[outback_ute]

Originally Posted by burnz

otto engine 1876 i think, OHC
1912 for a 4V DOHC.

1949 oldsmobile OHV
not shure what year with the ford flathead tho.

Looking at the video of the Otto engines on http://en.wikipedia.org/wiki/Otto_engine the cams are on the shaft running beside the cylinder.

From what I can find with a quick search on OHV - a 1886 Daimler patent for an engine included an ohv exhaust valve. 1902 David Dunbar Buick developed and engine with both valves ohv. 1904 Lanchester cars with ohv sold commercially. Even in the US there were plenty of ohv used prior to the Olds V8 - but in manufacturers no longer in existence hence lack of info on Wikipedia. From a practical point of view the ohv had to be invented before you could have an ohc!

More relevant to the topic, when looking at that I came across the CamInCam system used on the Viper V10 which could be further developed to give TiVCT, and refers to GM having it already - http://www.sae.org/automag/technewsl...ertrain/04.htm

[burnz]

Originally Posted by outback_ute

Looking at the video of the Otto engines on http://en.wikipedia.org/wiki/Otto_engine the cams are on the shaft running beside the cylinder.

From what I can find with a quick search on OHV - a 1886 Daimler patent for an engine included an ohv exhaust valve. 1902 David Dunbar Buick developed and engine with both valves ohv. 1904 Lanchester cars with ohv sold commercially. Even in the US there were plenty of ohv used prior to the Olds V8 - but in manufacturers no longer in existence hence lack of info on Wikipedia. From a practical point of view the ohv had to be invented before you could have an ohc!

More relevant to the topic, when looking at that I came across the CamInCam system used on the Viper V10 which could be further developed to give TiVCT, and refers to GM having it already - http://www.sae.org/automag/technewsl...ertrain/04.htm

interesting little tidbit
http://www.motorera.com/history/hist03.htm
The T-head engine gave way to the L-head (also called the flat-head or side-valve) engine in which valves were placed on one side of the engine. The L-head dominated the scene for years. Ford used it on V8s until 1953. But waiting in the wings was another design, introduced in 1898 by Wilkinson Motor Car Co. -- an engine that had the camshaft and valves in the cylinder heads. You know it as the overhead-cam (OHC) or overhead-valve (OHV).

[castellan]

Originally Posted by outback_ute

Surely the Gen III was new block and heads at the same time?

Are you sure? Not aware of any engines pre-1900 that didn't use pushrods.

The gen III also has a iron block version as well for trucks.

The design of a motor being OHV or OHC or DOHC has to do with it's function. just like springs being leaf springs they have there positives & negatives.

Do you think a ford v8 5.4L is better then a gen 4. why!

[chevypower]

Originally Posted by castellan

Do you think a ford v8 5.4L is better then a gen 4. why!

For low-end torque, yes. For high revving power, no.

[outback_ute]

Originally Posted by castellan

The gen III also has a iron block version as well for trucks.

The design of a motor being OHV or OHC or DOHC has to do with it's function. just like springs being leaf springs they have there positives & negatives.

Do you think a ford v8 5.4L is better then a gen 4. why!

Did that use the same heads, was it a new block? Just curious re the statement they've never changed both at once.

Pushrods do have their advantages, but maximising efficiency is not one of them and that is what manufacturers have to work on.

Why use the Boss motor as an example, we all know that is hampered by the stroke dimension and restriction on revs that results. Nothing to do with DOHC/pushrod.

[burnz]

you can VVT pushrod a 4Valve unit, nothing new cummins, cat, have been doing it for years.

[irlewy86]

Pity GM put all their eggs in the Volt basket and the next line of V8's will be developed on using money psyphoned out of other business units.

Take a look at what Lutz is saying, either the small blocks getting a new block or its getting new heads. But he cant develop a whole engine at once.

[4Vman]

"Grandads axe" was a very apt description...

[Bad Bird]

Sorry, wrong thread...

[sleekism]

I thought GM had already developed VVT pushrod engines as well as ones with 3 valve heads. I remember the LS7 was originally supposed to have a 3 valve head.

Also doesn't BMW and Moto Guzzi already succesfully run motorcycle engines with 4 valves per head?

[boris]

Also doesn't BMW and Moto Guzzi already succesfully run motorcycle engines with 4 valves per head?[/QUOTE]


As do most other motorcycle companies, for a long time!

[mcnews]

And Yamaha ran five valve head for nigh on 20 years. And then of course there was Honda with an eight valve per cylinder design...

[sleekism]

Originally Posted by boris

As do most other motorcycle companies, for a long time!

What I meant was that Moto Guzzi have an engine that runs 4 valves per head using pushrods so why can't car manufacturers?

The Moto Guzzi is a 1200cc pushrod V-twin with 4 valves per head making 80kw@7500rpm times that by four and you have a 4.8L V8 making 320kw! :

[Wally]

Originally Posted by sleekism

What I meant was that Moto Guzzi have an engine that runs 4 valves per head using pushrods so why can't car manufacturers?

The Moto Guzzi is a 1200cc pushrod V-twin with 4 valves per head making 80kw@7500rpm times that by four and you have a 4.8L V8 making 320kw! :

I guess to do that the complexity of head design and manufacture starts to approach that of a DOHC and thus the cost benefit diminishes. It would probably also require a double up on cam lobes and push rods, which may add even more mass and flex to the valvetrain. The cam tunnels would need to be beefed up and the block revised for increased rigidity and consequential weight.

[4117kev]

[QUOTE=sleekism]What I meant was that Moto Guzzi have an engine that runs 4 valves per head using pushrods so why can't car manufacturers?

These heads are out there and available as straight bolt on's so as you say why don't the manufacturers use them.

i think a 6.2lt 4valve motor would sound pretty wicked and to throw in a new cam (aftermarket) would not cost you 4 grand as it does with the overhead cams.

Don't get me wrong on here I love my boss motor but why would I spend 25-30 grand on it for 500hp when i could get 700hp for the same money by doing a SBC using the same fuel.

[olds]

The future doesn't involve 8 cyls

[xbgs351]

Originally Posted by olds

The future doesn't involve 8 cyls

12 or 16?

[Chilliman]

At this late stage in the game I can't see GM going in a totally different direction to the current push-rod small block architecture - they don't have the cash anyway. Isn't the new V8 that this article is alluding to the GEN V 5.5Litre OHV V8 with direct injection? I think the variable timing statement maybe a bit of a furphy or something that won't be available until much later. GEN V is supposed to be production ready by 2012?

[olds]

Originally Posted by xbgs351

12 or 16?

Electric

[ebxr8240]

Isn't the block they use in V8 series a twin cam engine as well ???
They will make a new V8 when Daewoo make one ???

[mickyyyy]

Pushrod engines sound better and are so easy to work on and last forever. throw on a Direct injection system to make them more eco friendly and away u go again. Only OHC engines i like are ford inline 6, Barra & toyota 1JZ & 2JZ.

[CobraJet351]

The future doesn't involve 8 cyls

My future involves lots of them

[Saraco]

I'm Talking About High Rpm Reliability, Not About Prodution Cars.

[4Vman]

Originally Posted by svov88

I'm Talking About High Rpm Reliability, Not About Prodution Cars.

He was talking about production cars, not race engines....