Question For Duke On The New Z06 5.5L DOHC V-8

[Larry E.]

Duke>Unless I missed it on reading up on this new V8 it I have not seen info on the type of chambers in the
heads. Would it have "hemispherical combustion chambers" and considered a "HEMI"? Also does it have
a new built from the ground Block? Or some type of modified LS block? Thanks in advance>Larry

[Duke W.]

Re: Question For Duke On The New Z06 5.5L DOHC V-8

My understanding is that the block is unique, but it retains the 4.4" small block bore centers that dates back to the 265. Bore and stroke are 4.104" by 3.15".

I haven't seen any detail data on the combustion chamber design, but 4-valve heads usually have pentroof chambers with small quench areas on both sides. I haven't seen a valve included angle, but I suspect it is fairly narrow, like 25-30 degrees so the chambers are shallow.

Duke

[Michael J.]

Re: Question For Duke On The New Z06 5.5L DOHC V-8

I also find it curious torque is so low (as compared to HP), but I guess this is not a long stroke, push-rod V8, is it?

[Duke W.]

Re: Question For Duke On The New Z06 5.5L DOHC V-8

This new engine has a greater specific torque output than any prior GM naturally aspirated road legal engine and may be one of the best on the market today in terms of specific NET torque and power output. Consider that most 427s (7 liters) from the sixties were rated at 460 lt-ft GROSS torque while this 5.5 liter engine makes 460 lb-ft NET torqued, SAE certified!

Look at the second sticky, Z06 Reveal, posts 15 and 16. The narrative is from three posts I made on the CF C8 Z06 forum then copied and pasted over here onto Vinnie's sticky.

Duke

[Michael J.]

Re: Question For Duke On The New Z06 5.5L DOHC V-8

I guess I am hopelessly old fashioned, but I prefer a supercharged or naturally aspirated push rod V8 to any other engine in a performance car, or truck. I have had supercharged and natural aspirated OHC V8s, but although the HP is up there when you get to high RPMs, the torque is always lacking, especially at the low end. To each his own.

[Mark E.]

Re: Question For Duke On The New Z06 5.5L DOHC V-8

I guess I am hopelessly old fashioned, but I prefer a supercharged or naturally aspirated push rod V8 to any other engine in a performance car, or truck. I have had supercharged and natural aspirated OHC V8s, but although the HP is up there when you get to high RPMs, the torque is always lacking, especially at the low end. To each his own.

Michael,

Yet, speaking of low-RPM torque, don't you have at least one small block car with a 30-30 cam?

[Joe L.]

Re: Question For Duke On The New Z06 5.5L DOHC V-8

My understanding is that the block is unique, but it retains the 4.4" small block bore centers that dates back to the 265. Bore and stroke are 4.104" by 3.15".

I haven't seen any detail data on the combustion chamber design, but 4-valve heads usually have pentroof chambers with small quench areas on both sides. I haven't seen a valve included angle, but I suspect it is fairly narrow, like 25-30 degrees so the chambers are shallow.

Duke

Duke------


Regardless of what the GM "party line" says, I believe this engine was derived from the Cadillac "Blackwing" engine. That engine was a DOHC design and was developed for use in top-of-the-line Cadillacs. However, it only saw very limited use for a few model years and has been dropped for use in Cadillacs. I don't see any way that GM would invest to develop a new, "clean sheet of paper" engine, use it sparingly and, then, develop another entirely new, exceedingly low production DOHC engine for the Corvette. I believe the major difference between the Blackwing engine and the Corvette engine is the flat plane crank in the Corvette engine.

This is not an age when the major auto manufacturers are going to get too interested in developing new, "clean sheet of paper" V-8 engines, especially those that have little potential for use in trucks.

[Michael J.]

Re: Question For Duke On The New Z06 5.5L DOHC V-8

Yes, I have 4 of them, and I much prefer driving the 427s......they lauch much more quickly and are much more satisfying off the line. But fuelies are special in so many other ways, not connected to performance. But I have to admit in the small block fuelies the rear end ratio makes a big difference, my '63 with the 4.56 gears is as satisfying as the 427s.....

[Patrick B.]

Re: Question For Duke On The New Z06 5.5L DOHC V-8

The valve train illustrations for Z06 engine seem to show sliding contact between the cams and followers. Am I missing a roller somewhere? How does this design get around low zinc modern oil problem?

[Larry E.]

Re: Question For Duke On The New Z06 5.5L DOHC V-8

[QUOTE=Michael Johnson (49879);903598. But I have to admit in the small block fuelies the rear end ratio makes a big difference, my '63 with the 4.56 gears is as satisfying as the 427s.....[/QUOTE]

Very True: Upon reading some of the New Z06 Specs. I thought I read where Chevrolet is increasing the rear end ratio to
5+ numerically. With all the forward gears and a good portion of them being "overdrive" gears this can be done. That being
said it tells me that this new V8 has absolutely no very low end torque for stop and go traffic launch by itself. Larry

[Larry E.]

Re: Question For Duke On The New Z06 5.5L DOHC V-8

Duke------


Regardless of what the GM "party line" says, I believe this engine was derived from the Cadillac "Blackwing" engine. That engine was a DOHC design and was developed for use in top-of-the-line Cadillacs. However, it only saw very limited use for a few model years and has been dropped for use in Cadillacs. I don't see any way that GM would invest to develop a new, "clean sheet of paper" engine, use it sparingly and, then, develop another entirely new, exceedingly low production DOHC engine for the Corvette. I believe the major difference between the Blackwing engine and the Corvette engine is the flat plane crank in the Corvette engine.

This is not an age when the major auto manufacturers are going to get too interested in developing new, "clean sheet of paper" V-8 engines, especially those that have little potential for use in trucks.

Joe: I understand your point of view but you will have to explain why the New Corvette V8 has different bore spacing than the
now defunct Cadillac Blackwing Engine. 4.4 inch vs. 3.779 inch. Larry

[Michael G.]

Re: Question For Duke On The New Z06 5.5L DOHC V-8

First off, ‘Cadillac’, as a separate engineering entity, ceased to exist in the ‘80s. Any current GM engine design was done by GM Powertrain, a single entity. While I don’t have any knowledge of the differences and similarities between the “Blackwing” design and the the new Corvette Z06 V8 design, it would be logical that much of the technology developed for “Blackwing” would be used on the new V8 as many of the same people were likely involved. Perhaps (just a guess) the flat-plane crank required a different bore spacing and new block, but much of the rest was carried over.

[Larry E.]

Re: Question For Duke On The New Z06 5.5L DOHC V-8

False>Read the following>
GM Inaugurates New Performance and Racing Center

Cutting-edge development facility leverages global Powertrain resources

Print Email Word Add Thiscarrying that momentum into 2016

• IndyCar 2.2L Twin-Turbo V-6NHRA COPO Camaro V-8 enginesCorvette Racing 5.5L V-8

Additionally, the high-performance crate engines and crate powertrain systems offered by Chevrolet Performance are developed at the new facility.

[Michael G.]

[Joe L.]

Re: Question For Duke On The New Z06 5.5L DOHC V-8

False>Read the following>
GM Inaugurates New Performance and Racing Center

Cutting-edge development facility leverages global Powertrain resources


Print Email Word Add This



“Chevrolet earned six manufacturer and five driver championships in 2015, and we are carrying that momentum into 2016,” said Jim Campbell, GM U.S. vice president of Performance Vehicles and Motorsports. “This new center is a valuable tool in developing powertrains with the right combination of performance, durability and efficiency to help our drivers and teams win races and championships.”
The racing engines under responsibility at the new center include:

• NASCAR “R07” – a unique 358-cubic-inch V-8 engine designed and developed exclusively for NASCAR Sprint Cup racing
• IndyCar 2.2L Twin-Turbo V-6 – a technical marvel that uses a pair of high-boost-producing turbochargers to help extract about 700 horsepower from the small-displacement, direct-injected V-6
• NHRA COPO Camaro V-8 engines – racers competing with a new 2016 COPO Camaro in NHRA’s Stock and Super Stock eliminator classes can select from supercharged and naturally aspirated LS- and LT-family engines
• Corvette Racing 5.5L V-8 – Based on the production LT engine family, the naturally aspirated and all-aluminum 5.5L V-8 engine is used by the Corvette Racing C7.R team.

Additionally, the high-performance crate engines and crate powertrain systems offered by Chevrolet Performance are developed at the new facility.

Larry------

The NASCAR and Indy engines are not based on any PRODUCTION GM engine. They are totally purpose built engines and, as far as I know, are not even manufactured in any GM manufacturing facility. They may or may not have been designed in-house by GM but I have been told that even the design was out-sourced.