Is the 427 in the z28 same as the 427 in c6 z06? - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Kokoa87 · 11-22-2014, 01:37 PM

Hennessy guy on YouTube who fit a H package on a z28 said the heads aren't the same ,

If thats true and I believe him why did Chevy do this ?

Is it a sub 427 ? Save money ?

He said they did it to get better flow because it's not the same 427 as on the z06

gto406 · 11-22-2014, 02:09 PM

Pretty certain they are both LS7's (assuming we are talking about a c6 Z06).

The 2013 c6 Z06 was rated at 505hp, and 470lb-ft of torque whereas the 2015 Z/28 is 505hp and 481lb-ft of torque.

More info on the 427 here: http://www.chevrolet.com/performance...gines/ls7.html

2014 overview/specs on Z/28 based LS7: http://media.gm.com/media/us/en/gm/n...-z281-ls7.html

Kokoa87 · 11-22-2014, 02:56 PM

Yes but I'm saying the Hennessy guy says the heads are actually different

So the heads are not the same as the ones on the z06 427

Zslash28 · 11-22-2014, 03:27 PM

A quick search regarding the Z06 and Z/28 heads brings up exactly the same info on the Corvette Museum site (Z06) and the GM media site (Z/28).

Post up the youtube Hennessy guy, I want to hear what he has to say...

Boother · 11-22-2014, 04:02 PM

Quote:

Originally Posted by Kokoa87

Hennessy guy on YouTube who fit a H package on a z28 said the heads aren't the same ,

If thats true and I believe him why did Chevy do this ?

Is it a sub 427 ? Save money ?

He said they did it to get better flow because it's not the same 427 as on the z06

The HEADERS are different, not the heads.

Skylane765 · 11-22-2014, 04:22 PM

Quote:

Originally Posted by Kokoa87

Hennessy guy on YouTube who fit a H package on a z28 said the heads aren't the same ,

If thats true and I believe him why did Chevy do this ?

Is it a sub 427 ? Save money ?

He said they did it to get better flow because it's not the same 427 as on the z06

We have formed headers on the LS7 Z28 the Vett does not, that's what gave a little more power to the Z28.

gto406 · 11-22-2014, 04:51 PM

As noted elsewhere (media.gm.com...)

"The LS7 exhaust system for the Z/28 is unique and features a tri-Y header design to take advantage of the V-8’s firing order. Primary pipe pairings join cylinders one and five, then three and seven on the left bank, with cylinders two and four and six and eight paired on the right bank. At each bank, the primary pairings collect into a secondary Y, delivering a combination of pulse separation of adjacent firing cylinders and improved scavenging for the engine’s firing order of 1-8-7-2-6-5-4-3. A dual-mode exhaust system and large, three-inch-diameter pipes complement the manifolds’ tuning and low restriction. The optimized header and exhaust system improves torque and sound quality from the LS7 engine"

Explains the bump in the Z's torque rating vs. c6/Z06.

DrkPhx · 11-22-2014, 06:14 PM

I thought some of the internal components like the pistons were changed?

Kokoa87 · 11-22-2014, 06:55 PM

Quote:

Originally Posted by Zslash28

A quick search regarding the Z06 and Z/28 heads brings up exactly the same info on the Corvette Museum site (Z06) and the GM media site (Z/28).

Post up the youtube Hennessy guy, I want to hear what he has to say...

http://m.youtube.com/watch?v=j9UoCo9vheQ

Kokoa87 · 11-22-2014, 06:56 PM

Quote:

Originally Posted by Boother

The HEADERS are different, not the heads.

Ok that makes sense. Thanks for the input

Just wanting to find out if gm went cheap on it for the z28

Zslash28 · 11-22-2014, 07:51 PM

Quote:

Originally Posted by Kokoa87

Just wanting to find out if gm went cheap on it for the z28

This makes no sense. The LS7 heads are a very sophisticated head design. It would be foolish for GM to change the design to other than the best on their flagship Camaro.

I wish the guy on YouTube was specific other than a blanket statement about the heads that only casts doubt and brings up questions that have no answers. He also says the ZL1 feels like it has more grunt than a Z/28, I laughed when I heard this,...duh, it has a supercharger.

Edit: I believe the Hennessy guy mentioned they ported the factory heads. IIRC there was some debate about the porting and removal of the intake port deflector located just prior to the valve.

Splitter · 11-22-2014, 08:02 PM

Quote:

Originally Posted by Zslash28

duh, it has a supercharger.

This.

soulsea · 11-22-2014, 08:04 PM

We're talking about Hennessey here ... I wouldn't trust them to do an oil change.

Kokoa87 · 11-22-2014, 08:54 PM

Ya I understand but I don't trust GM either. They do what they can to cut costs
Mark it up and say wow look at this !

So I'm just trying to find out the truth before I get one or not

11-22-2014, 01:37 PM	#1
Kokoa87 Drives: 1968 Join Date: Nov 2014 Location: Cuyahoga falls ohio Posts: 45	Is the 427 in the z28 same as the 427 in c6 z06? Hennessy guy on YouTube who fit a H package on a z28 said the heads aren't the same , If thats true and I believe him why did Chevy do this ? Is it a sub 427 ? Save money ? He said they did it to get better flow because it's not the same 427 as on the z06

11-22-2014, 02:09 PM	#2
gto406 Drives: 1972 GTO, 1969 Firebird Join Date: Dec 2013 Location: Detroit MI, Posts: 42	Pretty certain they are both LS7's (assuming we are talking about a c6 Z06). The 2013 c6 Z06 was rated at 505hp, and 470lb-ft of torque whereas the 2015 Z/28 is 505hp and 481lb-ft of torque. More info on the 427 here: http://www.chevrolet.com/performance...gines/ls7.html 2014 overview/specs on Z/28 based LS7: http://media.gm.com/media/us/en/gm/n...-z281-ls7.html Last edited by gto406; 11-22-2014 at 02:20 PM.

11-22-2014, 02:56 PM	#3
Kokoa87 Drives: 1968 Join Date: Nov 2014 Location: Cuyahoga falls ohio Posts: 45	Yes but I'm saying the Hennessy guy says the heads are actually different So the heads are not the same as the ones on the z06 427

11-22-2014, 03:27 PM	#4
Zslash28 Jumanji Drives: '14 Z/28 - AGM - No A/C Join Date: Mar 2014 Location: Alaska Posts: 1,693	A quick search regarding the Z06 and Z/28 heads brings up exactly the same info on the Corvette Museum site (Z06) and the GM media site (Z/28). Post up the youtube Hennessy guy, I want to hear what he has to say...

11-22-2014, 04:51 PM	#7
gto406 Drives: 1972 GTO, 1969 Firebird Join Date: Dec 2013 Location: Detroit MI, Posts: 42	As noted elsewhere (media.gm.com...) "The LS7 exhaust system for the Z/28 is unique and features a tri-Y header design to take advantage of the V-8’s firing order. Primary pipe pairings join cylinders one and five, then three and seven on the left bank, with cylinders two and four and six and eight paired on the right bank. At each bank, the primary pairings collect into a secondary Y, delivering a combination of pulse separation of adjacent firing cylinders and improved scavenging for the engine’s firing order of 1-8-7-2-6-5-4-3. A dual-mode exhaust system and large, three-inch-diameter pipes complement the manifolds’ tuning and low restriction. The optimized header and exhaust system improves torque and sound quality from the LS7 engine" Explains the bump in the Z's torque rating vs. c6/Z06.

11-22-2014, 06:14 PM	#8
DrkPhx Drives: 2013 Triple Black ZL1 / 2006 TB SS Join Date: Feb 2011 Location: MN Posts: 2,250	I thought some of the internal components like the pistons were changed?

11-22-2014, 08:04 PM	#13
soulsea Drives: Fast Join Date: Sep 2014 Location: Mt Pleasant SC Posts: 252	We're talking about Hennessey here ... I wouldn't trust them to do an oil change.

11-22-2014, 08:54 PM	#14
Kokoa87 Drives: 1968 Join Date: Nov 2014 Location: Cuyahoga falls ohio Posts: 45	Ya I understand but I don't trust GM either. They do what they can to cut costs Mark it up and say wow look at this ! So I'm just trying to find out the truth before I get one or not