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intrigued

LS3 in LS2 out?

11 posts in this topic

intrigued    9

AS you all probably know the 08 vette has the new 6.2 450 hp LS3 v8 standard replacing the 6.0 400 hp LS2. Anybody know anything about the LS3 besides the 450 hp figure? Tourque, redline, power band etc? Does it have DOD or VVT or both?

What cars do you think it will end up in as all of the recent LS2 cars are dead. No more SSR, GTO, or CTS V. The future CTS-V is supposed to get at least 500 hp so this engine won't end up there. Will this be exclusivley a Vette engine? What do you guys think...

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Northstar    11

It will probably show up in the Camaro and other future Zetas. Perhaps a Silverado SS as well.

Where is the 450HP figure confirmed?

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Camino LS6    866

I saw this on CZ28 weeks ago and forgot to post it here. :banghead:

I can't remember for sure, but I think that the 450HP is an official GM #.

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dwightlooi    259

Maybe they can put DI on it. It should be relatively easy given that the Pushrod actuated OHV head is much less "crowded" than a DOHC 4-valve design. The pushrods are to one side and the spark goes in on the other side. The DI injector can go straight down through top of the valve cover between the rocker arms. You'll have a kidney shaped chamber with the spark and the injector both nestled between the valves.

I think synchronous VVT should be incorporated on the inblock cam since its integration is simple enough. AFM (DOD) should also be on there. If they really want to go overboard, put in a pair of balance shafts in the crankcase on the valley of the Vee driven at twice engine speed. The 90 degree V8, cross plane or not, has residual 2nd order vibrations just like an I4. Quell it and the engine will feel a lot more refined. Another thing to consider is a completely belt free accessory drive. The water pump, alternator and A/C compressor can all be driven via helical gears and/or roller chains in the back of the block. This will make no part replacements for 200,000 miles a reality -- assuming the accessories themselves hold up that is.

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intrigued    9

It will probably show up in the Camaro and other future Zetas. Perhaps a Silverado SS as well.

Where is the 450HP figure confirmed?

Northstar,

Im almost positive it stated a 450 hp figure on the 2008 vette updates list in the chevy forum.

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Maybe they can put DI on it. It should be relatively easy given that the Pushrod actuated OHV head is much less "crowded" than a DOHC 4-valve design. The pushrods are to one side and the spark goes in on the other side. The DI injector can go straight down through top of the valve cover between the rocker arms. You'll have a kidney shaped chamber with the spark and the injector both nestled between the valves.

I think synchronous VVT should be incorporated on the inblock cam since its integration is simple enough. AFM (DOD) should also be on there. If they really want to go overboard, put in a pair of balance shafts in the crankcase on the valley of the Vee driven at twice engine speed. The 90 degree V8, cross plane or not, has residual 2nd order vibrations just like an I4. Quell it and the engine will feel a lot more refined. Another thing to consider is a completely belt free accessory drive. The water pump, alternator and A/C compressor can all be driven via helical gears and/or roller chains in the back of the block. This will make no part replacements for 200,000 miles a reality -- assuming the accessories themselves hold up that is.

I'm not sure who you are, but welcome to the forum. I like the way you think!

Also, why do we not have more gear-drive cams out there these days!?

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dwightlooi    259

I'm not sure who you are, but welcome to the forum. I like the way you think!

Also, why do we not have more gear-drive cams out there these days!?

A few reasons...

(1) Because gears are not practical when the driven spool is far away from the driving spool. Eg. with OHC engines you'll need around four gears in series to reach the top of the head. This is why chains are preferred -- chains typically last the lifetime of the engine anyway and are more practical because you can snake them around just like belts.

(2) Gears are noisier and so are chains (albeit a little less so). And more importantly they have practically no slop. This is actually bad for the engine. Harmonic dampers are but on the crank pulley for a reason. You don't want to directly couple loads rigidly to the crank or vice versa. Its hard on the accessory and hard on the engine to not have a little "rubber band effect" to cushion the shock loads.

(3) Belts are CHEAP. The last time I checked accessory belts costs $5 to $20 a piece at the store. I am sure GM pays less. A gear, chain or gear+chain drive will cost more to manufacture.

(4) There have been certain engines with chain and/or gear driven accessories. One example that comes to mind is the somewhat short-lived VW-Audi W8 engine. In this particular engine, I think the A/C compressor was driven via a shaft connected to a gear sprocket on the timing chain at the back of the engine block. This reduces the belt drive for other accessories to ONE thin belt instead of two and allows for tighter packaging.

Posted ImagePosted ImagePosted Image

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Running the water pump directly off the cam has been done, or even gear driving it. The DuraMax's water pump is gear driven directly off the timing system. And the LT-1 engine from the mid-90s had the water pump driven directly off the cam. AS far as the timing set up being a gear drive the main complaint is noise levels. Sure you'll sound like you have a 6-71 blower strapped to it, but most people don't necessarily want that. I think that I'm going to actually gear drive my old 350 in my truck in its next life. As far as the LS-2, it'll still be around in most of the trucks. The LS3 is going to be used mostly as a hi-output engine for special puposes.

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(1) Because gears are not practical when the driven spool is far away from the driving spool. Eg. with OHC engines you'll need around four gears in series to reach the top of the head. This is why chains are preferred -- chains typically last the lifetime of the engine anyway and are more practical because you can snake them around just like belts.

I guess so.... I've got nothing against Chains but still a synchro gear is even more durrable.

(2) Gears are noisier and so are chains (albeit a little less so). And more importantly they have practically no slop. This is actually bad for the engine. Harmonic dampers are but on the crank pulley for a reason. You don't want to directly couple loads rigidly to the crank or vice versa. Its hard on the accessory and hard on the engine to not have a little "rubber band effect" to cushion the shock loads.

I've never heard tis, makes sense but from my understanding

the tolerance on timing does not factor is rubber band effect

in the case of chains... does it?

(3) Belts are CHEAP. The last time I checked accessory belts costs $5 to $20 a piece at the store. I am sure GM pays less. A gear, chain or gear+chain drive will cost more to manufacture.

Yeah... well you DO realize the Dirty Japanse put those frikkin rubber bands in there

instead of chains to MAKE sure you have to replace it within X amount of milage.

That's like saying "well $hit so you blew a head gasket in your Nortstar... it only

costs $15 for a replacement...."

Ummm.... okay so you going to give me the $1300 for the repair since it will take

about 20 bloody effin hours to replace said head gasket????

Saying a rubber timing belt is fine because it only costs $20 is very shortsighted!

(4) There have been certain engines with chain and/or gear driven accessories. One example that comes to mind is the somewhat short-lived VW-Audi W8 engine. In this particular engine, I think the A/C compressor was driven via a shaft connected to a gear sprocket on the timing chain at the back of the engine block. This reduces the belt drive for other accessories to ONE thin belt instead of two and allows for tighter packaging.

Posted ImagePosted ImagePosted Image

Shortlived? Is the W8 dead?

At any rate as cool as it was it's another retarded motor in terms of maintenance.

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dwightlooi    259

I guess so.... I've got nothing against Chains but still a synchro gear is even more durrable.

I've never heard tis, makes sense but from my understanding

the tolerance on timing does not factor is rubber band effect

in the case of chains... does it?

Yeah... well you DO realize the Dirty Japanse put those frikkin rubber bands in there

instead of chains to MAKE sure you have to replace it within X amount of milage.

No not for the valve gear drive. That pretty much have no "rubber banding" whether it is a gear, chain or belt drive.

But it is common to put harmonic dampers on the crank pulley of the accessory drive loop. The water pump, alternator, clutchfan and/or A/C compressor does not need to be synchronous with the engine timing. Its like the little spring packs you find on clutches which allows for some give between the shaft driven input and the friction discs. Racing clutches don't have them but every regular

factory clutch does. In the case of the accessory drive pulley they are frequently made from some kind of rubber. In both cases they act to cushion shock loads.

That's like saying "well $hit so you blew a head gasket in your Nortstar... it only

costs $15 for a replacement...."

Ummm.... okay so you going to give me the $1300 for the repair since it will take

about 20 bloody effin hours to replace said head gasket????

Saying a rubber timing belt is fine because it only costs $20 is very shortsighted!

Shortlived? Is the W8 dead?

At any rate as cool as it was it's another retarded motor in terms of maintenance.

Yes. It is dead after a mere 2 years. The new Passat is based on the Jetta platform and uses a transverse 3.6 liter DOHC VR6 engine making 280hp. The 3.6 liter is a 10.6 degree V6. The Audi's never used the W8 but rather a series of 90 degree 2.8/3.0/3.2 liter V6es or 4.2 liter V8s. The latest versions being direct injected and making 255hp and 420hp respectively. The Touareg SUV uses the Audi 4.2 liter 90 degree engine or the 3.2 and later 3.6 liter VR6es. The Passat W8 was the only car to use to W8 engine. Now that the B5.5 Passat is gone, the engine is dead. The only remaining W-engine is the 6.0 liter W12 used in the Phaeton and the Audi A8. The 8-cylicner version of these cars use the Audi 4.2 liter 90 deg V8.

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