So, what exactly is known about these motors? Direct injection is probably a given. Are they substantially different than the Gen IVs, or is it going to be more like the transition from Gen IIi to Gen IV, which was basically nothing. The architecture remained almost completely the same in that scenario.

Are these motors still going to be pushrod (I get the feeling they will). VVT? Any of that dual camshaft stuff that was on the XV8 concept? Anyone who has any info care to divulge what they can?

 

Those documents on future contracts which the UAW made public last year, are a wealth of info on the Gen5 motors.

The changes are substantial.

 

When are they coming out? Will the launch of the C7 use gen IV or gen V?

 

Are there any links to them?

edit: I've found this about GMs 2 cam-in-block 3 valve DI V8 http://www.google.com/patents?id=sjQ...505592#PPA1,M1

 

This is one I know of...Is this the one you were talking about Charlie?

http://www.futureoftheunion.com/docs...er149pages.pdf

EDIT:

According to the .pdf I just linked, the Gen V engines will be E85 capable (taken from the Rochester plant commitments section):

"GM will award the new product programs for Fuel Rails, IAFM’s & IAM’s,
SIDI, LOMA and Canisters (Note: E85 injectors are included as part of the
Fuel Rails/SIDI system). GM will commit these product programs (for
specific program details see the charts included in Attachment A-1), with
the potential for additional new product programs as they are released.

--The most significant programs for the site are the GMPT SIDI
programs for the next generation (Gen V) engines."

And according to the article. The Gen V engines (both OHC, and OHV) will have cylinder deactivation.
a 6.2 OHC, and a "5X" OHV version will both have that.

These engines (again - according to the article) are supposed to start production between 2010, and 2011.

Now...here's something interesting (I'm typing this as I read). In addition to multiple entries of "Gen V SIDI", theres a mention of a "Gen V MPFI" on page 54. (Multi-port fuel injection???) hmmmmmm....

That's all I could really find in there.

 

2003!!! And they haven't done anything with that, yet??

 

So the GM DOHC V8 is different to the recently canceled Cadillac V8? In other words GM will not be making a V8 exclusively for Cadillac but will instead continue to offer buyers the choice of (interchangeable) heads?

Yes, both statements are questions.

PS Still prefer the GM cam-in-block engine but would love to see a direct comparison b/t the values of 'high-tech' and 'low-tech'.

 

The Reader's Digest version of it is going to break down like this (assuming naturally aspirated motors):

For a given weight and size, an OHV engine will end up having a higher displacement than an OHC engine.

The balance point comes when added top end power of the OHC engine offsets the added power inherent in the higher displacement of the OHV engine.

With the LSx motors, that balance point occurred somewhere between 500-600hp @ 7 liters of displacement... the point at which, to go any higher in power output and keep all the other considerations that an engine has to be designed for (NVH, fuel economy, durability, etc...), GM decided to go with forced induction.

The Viper's balance point, due to greater displacement, was higher in power output if that was the only factor considered, but I do not have the particulars on that motor regarding size and weight.

 

Gen 5

 

MPFI is what you have on the Gen IVs today. The first smallblocks to get this were the Camaro 5.0 and Corvette 5.7 in 1985, where they made 215 and 230hp, respectively. At the time, it was a lot of horsepower.

 

I think you mean 84 for the Corvette 5.7.

 

84 Didnt get TPI, 85 did. 84 got CFI or Crossfire Injection.

There is that talk of a DOHC version of the engine displacing 6.2 liters. I wonder what will come of that? How would you fit a DOHC head on an engine designed for OHV?
From what I understand, the Gen V wont look much different then a Gen III or IV. It will use the new L92 cylinder head design. Direct injection will be available. Im sure that VVT will return with maybe an upgrade?
My question is this talk of smaller engines using DI to maintain performance levels while getting much better gas milage? Will we see a wider range of small displacement V8s below 6 liters?

 

If you think small displacement is below 6 liters, you might be a musclehead.


~~Anyway, I'm in a wait and see mode for the new generation of motors. I'm hoping that what comes out is adequately powered and can get some decent efficiency out of whatever fuels, not to mention, it is still enthusiast friendly.

 

I'm still waiting to see who will be the first to put out a 3 valve pushrod V8

 

It's been done many times before, e.g. the Chevy 3.4 DOHC V6 was based on the OHV 60º V6.