future small block Chevy lineup

[schmallz]

Originally Posted by Olds88

DOHC doesn't offer the current pushrod LSx engines packaging or reliability. It'll make the motors pricier and more complex.

Throw it in a Cadillac, give it something exsclusive to stand out from the rest of GM's V8s.

There is no reason an Exspensive Car can't have an Exspensive Engine in an Exspensive Brand.

[asrapid]

Originally Posted by member12

I just never understood how they can do that. I've seen the inside of a 2v/cylinder small block, and I just couldn't see how they can do a 3V engine with the camshaft mounted inside the V.

It just seems like it would be easier just to put the camshaft over the clinder heads and make a 4v/cylinder DOHC motor.

Here is the patent for 3 valve with Di

http://www.google.com/patents?id=rzQ...m=4&dq=6505589

and here with 2 cam in block and DI (probably something similar to XV8 concept engine)

http://www.google.com/patents?id=sjQ...505592#PPA4,M1

So it can be done. Question is will Gm do it..maybe they'll do normal 2v with DI LS engine for trucks, chevy, pontiac etc and special 3v DI for cadillac.

[Slideways]

Originally Posted by wpageabc

Its all going smaller to comply with the new laws. Small block going to small size and big block going bye bye except aftermarket

The big block is gone. When was the last time you cold get a 2500 with an 8.1L?

[ctaylorzl1]

Originally Posted by Slideways

The big block is gone. When was the last time you cold get a 2500 with an 8.1L?

2006

[63GrandSport001]

Originally Posted by purplehaze

Seen this on autoweek forums.

Auto Week is not a very great source of information as it seems, the best sources of accurate information are from insiders on forums such as this one.

[63GrandSport001]

Originally Posted by asrapid

Here is the patent for 3 valve with Di

http://www.google.com/patents?id=rzQ...m=4&dq=6505589

and here with 2 cam in block and DI (probably something similar to XV8 concept engine)

http://www.google.com/patents?id=sjQ...505592#PPA4,M1

So it can be done. Question is will Gm do it..maybe they'll do normal 2v with DI LS engine for trucks, chevy, pontiac etc and special 3v DI for cadillac.

the Duramax diesel is a OHV 4 valve per head design however I dont know if that layout will go much further then that low rpm application.

[nailhead425]

The main benefit of DOHC engines is the abiilty for small-bore engines to breathe better and rev higher. The Ford Mod motors are an excellent example of how 3v and 4v heads will improve flow and make more power. The reason is the really small 90mm (3.54") bore. Larger valves are significantly shrouded by the cylinder walls and thus flow is limited.

On the Gen III/IV small blocks the head flow is amazing. There is a diminishing return to 3v and 4v heads with these engines. First, additional valves will flow too much at low rpm, decreasing efficiency, power and economy. Secondly, the horsepower gains on 6.0 and 6.2L engines would be met with a reduction in low-end torque. On high-end cars, 7.0L and up there maybe enough gains to develop a 3v head, but on smaller displacement engines current head designs support far more horsepower than most folks will ever utilize.

The DI, VVT, and 6-speed transmissions are the next step.

[63GrandSport001]

I completely agree that direct injection, VVT, and 6 speeds are what we will be seeing with the Gen V motors.

[zabolots]

Man, I'd LOVE to see a DI version of an LS engine. You could go with a smaller displacement (i.e. 5.3L) and have the same power (or more) as the LS3.

[member12]

I think the new CAFE standards will be the end of the small block in anything but the Vette.

[C/K Man]

HD pickups and large vans, too.