71 Chevelle LS6

[Stephen B.]

Re: 71 Chevelle LS6

I remember seeing LS-6 engines for sale over the parts calender until the early 1990's. As a matter of fact, I remember seeing LS-5, LS-6, and LS-7 engines for sale for $2,600 wholesale. We should have bought a few at that time. Bunky

[Stephen B.]

Re: 71 Chevelle LS6

I remember seeing LS-6 engines for sale over the parts calender until the early 1990's. As a matter of fact, I remember seeing LS-5, LS-6, and LS-7 engines for sale for $2,600 wholesale. We should have bought a few at that time. Bunky

[Tom P.]

Re: 71 Chevelle LS6

Over on TEAM CHEVELLE, we say no.
Although, that's kind of strange since an LS6 was available in the Vette in 71. But then again, an LS6 was available in the Chevelle in 70, but not in the Vette. Go figure.

[Tom P.]

Re: 71 Chevelle LS6

Over on TEAM CHEVELLE, we say no.
Although, that's kind of strange since an LS6 was available in the Vette in 71. But then again, an LS6 was available in the Chevelle in 70, but not in the Vette. Go figure.

[Terry M.]

Re: 71 Chevelle LS6

Tom,
There are some major differences between the 1970 A-body (Chevelle) LS6 and the 1971 Y-body (Corvette) engine. It is one of the remarkable examples of Chevrolet giving the same designator to two different engines, and the fact that they are so close together (adjacent model years) makes it doubly remarkable and confusing.

[Terry M.]

Re: 71 Chevelle LS6

Tom,
There are some major differences between the 1970 A-body (Chevelle) LS6 and the 1971 Y-body (Corvette) engine. It is one of the remarkable examples of Chevrolet giving the same designator to two different engines, and the fact that they are so close together (adjacent model years) makes it doubly remarkable and confusing.

[Warren F.]

Re: 71 Chevelle LS6

The story of the LS6 engine in the Corvette is quite interesting. It's was a matter of hierarchy in a way. While Duntov was still pushing thru the LS7 for the '70 model, there was no urgency for the LS6 to become an option for the Corvette, that was left for the Chevelle as its top option. However as the deproliferation program was being instituted to weed out low volume high cost options, which affected the LS7 option for Corvette, time constraints became an issue with emission certifying the LS6 for the Y body installation and as such for the very first time, the Corvette (the flagship of Chevrolet Motor Division) played second fiddle to another model. Duntov was not happy with this situation, and actually tried to push through the LS7 option for the '71 model year again. It shows up on the '71 Dealer Order sheets in 7/70. However with the edict for engines to run on the up and coming low lead / no lead fuels to be marketed, compressions were mandated to drop back to a more friendly compression ratio for compatibility with these new fuels. Hence the 9/70 revised Dealer Sales Order sheets show a revised LS6 option listing. This is also reflected in the 1971 Dealer Sales Album with revised sheets dated January '71 to replace the earlier sheets showing the LS7 option as available in 1971.

[Warren F.]

Re: 71 Chevelle LS6

The story of the LS6 engine in the Corvette is quite interesting. It's was a matter of hierarchy in a way. While Duntov was still pushing thru the LS7 for the '70 model, there was no urgency for the LS6 to become an option for the Corvette, that was left for the Chevelle as its top option. However as the deproliferation program was being instituted to weed out low volume high cost options, which affected the LS7 option for Corvette, time constraints became an issue with emission certifying the LS6 for the Y body installation and as such for the very first time, the Corvette (the flagship of Chevrolet Motor Division) played second fiddle to another model. Duntov was not happy with this situation, and actually tried to push through the LS7 option for the '71 model year again. It shows up on the '71 Dealer Order sheets in 7/70. However with the edict for engines to run on the up and coming low lead / no lead fuels to be marketed, compressions were mandated to drop back to a more friendly compression ratio for compatibility with these new fuels. Hence the 9/70 revised Dealer Sales Order sheets show a revised LS6 option listing. This is also reflected in the 1971 Dealer Sales Album with revised sheets dated January '71 to replace the earlier sheets showing the LS7 option as available in 1971.

[Dick W.]

Re: 71 Chevelle LS6

Another point on the LS 6. The Chevelle version had the closed chamber cast iron heads with I believe, 12.5-1 compression, the Corvette version had open chamber aluminum heads with 10.25-1 compression. Just a couple of the major differences as Terry mentions.

[Dick W.]

Re: 71 Chevelle LS6

Another point on the LS 6. The Chevelle version had the closed chamber cast iron heads with I believe, 12.5-1 compression, the Corvette version had open chamber aluminum heads with 10.25-1 compression. Just a couple of the major differences as Terry mentions.

[Joe L.]

Re: 71 Chevelle LS6

Dick-----

Yes, the 1970 Chevelle LS-6 used closed chamber, cast iron heads and the 1971 Corvette LS-6 used open chamber, aluminum heads. The 1970 LS-6 had a compression ratio of, nominally, 11.25:1. The 1971 Corvette LS-6 was, nominally, 9.0:1.

[Joe L.]

Re: 71 Chevelle LS6

Dick-----

Yes, the 1970 Chevelle LS-6 used closed chamber, cast iron heads and the 1971 Corvette LS-6 used open chamber, aluminum heads. The 1970 LS-6 had a compression ratio of, nominally, 11.25:1. The 1971 Corvette LS-6 was, nominally, 9.0:1.

[Dick W.]

Re: 71 Chevelle LS6

Oops. Another post when about half asleep. Brain outta gear, fingers in gear. Bad mix.

[Dick W.]

Re: 71 Chevelle LS6

Oops. Another post when about half asleep. Brain outta gear, fingers in gear. Bad mix.

[Clem Z.]

the GM/NHRA specs for the 71 corvette 454

are 10.1:1 CR,103.1 CC aluminum head,.095 piston dome,13.10 CC dome volume