Pounder

10,000 to rear wheels

grinder11

Are you using condescending language to ""criticize" the LS1/LS6 platforms? I would wager the C5 Z06 has far fewer catastrophic engine failures, and class action lawsuits, as well, than the C6 Z06. I have a built LS7 in my C5. I wish I'd never changed the original engine.......

Apocolipse

Nope - just pointing out the fact that when you start pushing the power envelope more things will go wrong. Just the way it goes when it comes to mechanical systems. If a LS7 had the same power output as a LS1 it wouldn’t have any issues.

grinder11

I disagree. If a product is engineered correctly, from a clean sheet of paper, power output will have little effect on reliability. In an all out racing engine, yes, higher rpm/power are commensurate with a decrease in reliability. In other words, modify the existing platform of the LS6 to achieve a 505hp output to match the LS7, yes, reliability of the LS6 SHOULD be less than it is at 405hp, and less than the the LS7@that same 505hp level. As for the LS7 not having any issues if it was the same power level as the LS1, I disagree again. If you use the same inferior vendors, materials, engineering, coatings, and machining, problems would exist at the same 345-350hp as it does at the 505hp level. Power output of a stock LS7 has nothing to do with the failures owners have experienced. I do agree that modifying an existing platform and expecting the same reliability as it had in stock form, is not realistic. But the LS7 in stock form SHOULD be just as reliable as the LS1 is in stock form-IF ENGINEERING, MACHINING, AND MATERIALS are of equal quality as the LS1 had. If GM didn't expect that, they wouldn't have offered the same, or better, warranty on the LS7......

Apocolipse

The thing is they DID just modify the ls1/6 to have 505hp…that’s literally the definition of the LS7.

Same engine with bigger bore, bigger stroke, and higher flowing heads.

They added Ti parts because the design of the LS1 engine needed them for it to spin that high / breathe that much and make the 505hp while sticking with emissions regulations. They also wanted to test out some exotic materials and coating technologies on a low production engine. Clearly they learned a lot from the LS7 as things kept changing as we progress through the years of LS/LT having Ti and fancy coatings.

Now they have a new engine with the C8Z and are using lessons learned from before to design the parts inside.

Pounder

you think that engine is going to be reliable ????

Pounder

Sorry to AHP for wrecking your thread !!!!

Mirek

Hey at least you bumped the thread for ‘em

grinder11

Disagree again. The LS7 is a totally different, clean sheet of paper design. A totally different block casting, with considerably more aluminum in it, longer, pressed in sleeves, a different oiling system, and the heads are a totally different design. There's a lot more to an LS7 than it being a 'hot rodded' LS1 OR LS6. As for your original argument about upping the power leading to being less reliable, the power output per cubic inch in the LS6 is 1.1706hp/per cubic inch, the LS7 has 1.1827hp/per cubic inch, a difference of 12/100hp per cubic inch, certainly not a highly tuned version of the LS6, because 12/100hp per cubic inch is virtually nothing. Again, the power output isn't the problem owners have had with the LS7, it is engineering, inaccurate machining by substandard vendors, and bean counter interference. It's not because of its specific high output. Using your argument, the original 327 small block should've been junk because it was a 'hot rodded' 283. But the 327 was one of the best, and most reliable V8s GM ever built!

grinder11

Yeah, free bump for you, Jake and Kohle!!

Suaveat69

What angle, 15* or 13*.

grinder11

I believe the stock LS7 is 12°, not aware of the AHP heads angle......

Apocolipse

Ls3 heads are 15 deg

Mirek

The Archangels are 12 degrees.

Mr. Gizmo

What is cost for these heads -- assume no trade as owners may want to keep the ls7 heads moth balled to go with the car at future sale time

Apocolipse

Guess they are saying their ls7 heads aren’t a fix? I thought this was a very strange thread too…

Turbo6TA

Maybe I am wrong, but how would LS3 heads even fit on an LS7 ?

The angle of the rocker arms are completely different between the LS3 and LS7 heads (I know for a fact that the rocker arms are not interchangeable between the two engines) ... and it has nothing to do with a 1.7 rocker ratio vs a 1.8 rocker ratio rocker arm.

92rsz

They said right at the end of the post you have to run an ls3 manifold to make it work. I'm assuming needing ls3 rockers was a given. I think the multiple qc issues are what plagued the ls7. I firmly believe there would be no examples at 100k+ miles if there was an engineering flaw with this motor.

grinder11

The engineering flaw was the original wall thickness of the exhaust valves. GM made an "engineering change" to the wall thickness on the exhaust valves in 2008(?), when they also changed vendors from ? to Mahle. The newer designed valves have about twice the wall thickness of the original design on the earlier exhaust valves ('06-sometime in '08). GM engineers were also advised by Del West to have an additional "polishing" step added to the Ti intakes, before the CrN coating, which they decided against, maybe due to bean counters(?). Most all of this info is in Hib Halverson's 'The relentless pursuit of power', found online. It's a long, but excellent read....

grinder11

That is kind of a confusing statement for AHP to make, isn't it? Good point, as I also thought their LS7 heads were "the fix". Kinda strange to say 'our fixed LS7 heads are a top notch fix', but then later say 'if you want a "permanent" fix, don't go with them, go with these'!??!