Please GM...upgrade the pistons in the LSA

[Super83Z]

Please upgrade the pistons in the LSA before it goes into the Z28. For the love of god don't use cast pistons in this car. These won't be Cadillacs but modified race cars. Its only a few hundred bucks.

If cast pistons go in that motor it will be viewed as another major for GM.

[Number 3]

Modified race cars?

[rodimus prime]

I would hope that the z28 would get forged pistons....seeing as 300hp evos even get forged internals.

[nfamous209]

even w/ cast pistons its still low compression, and can hold decent amount of boost. sure forged would have been better. atleast reassuring n e ways. have there been n e known LSA engine failures. i've done some google searching and came up w/ nothing yet. so thats a plus.

[99-LS1-SS]

The pistons themselves are aluminum-cast from a high-silicon alloy developed for its combination of strength and heat-management properties. Casting reduces noise-generating potential, compared to other high-performance piston materials such as forged aluminum, and is specified when NVH control is a priority. The hypereutectic pistons are also lighter than conventional steel, which translates to less reciprocating mass inside the engine. Less mass means greater efficiency, high-rpm capability and a feeling of immediate response as the engine builds revs. The LS9s pistons are made of forged aluminum. The key difference in material choice here, is the desire for refinement in the Cadillac application.

The combustion surface of the LSA pistons, or the top land, lacks the valve-relief pockets typical on high-performance engines with relatively high-lift valves. Rather, the LSA top lands are sumped, with a saucer-shaped indent that dips gradually from the outer edge of the piston. This design promotes a thorough mixing of air and fuel, and along with other durability enhancing features, allows a 9.1:1 compression ratio: higher than a conventional supercharged or turbocharged engine, for improved combustion efficiency.

I'm not terribly worried about the pistons in the LSA. I would expect them to hold pretty well up too around 700 horsepower. Anything above that and you should upgrade the pistons anyway. If they do go forged it will be a bonus but if they don't I'll still get it and mod it.

[KoTToN]

also please add some wings and a jetpack, besides being a modified race car they will also be bi-planes!

[JDBeck23]

I would be less worried about the cast part and more worried about the hyper-eutectic part. Those silicon infused cast aluminum pistons really REALLY dont like detonation. Which can occur very easily in a supercharged motor's combustion chamber.

Hyper-eutectic is great for NA, but not so good for supercharged cars. Even though the CR is 9.1:1, I personally would be very conscious of anything that could make the car run lean.

[Q-ship]

GM is not going to build a LSA just for the Z28.....You want forged pistons your going to have put them in the engine. GM will not put noisy forged pieces into the Cadillac and it would require a complete recert to put them into just the Camaro engine which would add to the cost. It is more than just throwing them into engine, there would be design, durability testing, emission cert, and NVH testing it is more than a few bucks. Beside there are plenty of people getting 600 hp or more out of supercharged LS3 and they have cast pistons, yes it would be added insurance but it isn't gonna happen.

[Super83Z]

Originally Posted by Number 3

Modified race cars?

Yes, there is no arguing the Z28 is the GT500 competitor. The GT500 has a forged rotating assembly and is pushing 900hp on the stock short-block with mods. Z28 guys are going to do the same thing with their cars.

If the Z28 gets a cast piston LSA, it will be the same shameful act they did when they put that god awful 7.5" 10-bolt rear-end behind the LS1.

[Milk 1027]

you underestimate how great of an engine the LSA is..................

[rodimus prime]

Originally Posted by Milk 1027

you underestimate how great of an engine the LSA is..................

But you would take forged pistons over cast right?


I mean a freaking 300 hp evo has them. Its not much exta work. Hell most cars have cam/intake/exhaust variations year by year anyways. Look at the 4th gen ls1s...almost no year had the same engine parts. Emissions certs LOL. Its not that big of a deal to replace pistons.

[Robin Lawrence]

Really there are benifits to a hyperutectic piston. A forged piston tends to expand more as it gets to operating temps. You have to add additional clearance with a forged piston to allow for that growth.

During the warm up cycle there can be an increase in wear due to the aditional clearance.

The hyperutectic is quieter and the knock sensors can be more sensitive verses a forged engine.

Some people are like my daughter, once she gets one thing she isn't happy and wants more. I am happy to first get the Camaro and now it looks like a Z28!

The LSA ia a stout combination, we need to realize that GM has to pull the parts from existing platforms. It'a about using what you have developed.

Looking at some of the CTS-V message boards has given me a lot of encouragement with my LSA conversion. These things are making some big power on stock shortblocks.


Robin

[Super83Z]

The Blue oval has no problem with the forged pistons they have been putting in the blown Cobras/GT500s.

Trust me when I say people are going to modify the hell out of these cars and push the power envelope as far as they can. Ford saw this and answered with a forged rotating assembly. GM can do it, they just need not to bow to the beancounters like they have countless times before. Hyperexpoldeit pistons are junk for the power levels the Z28 is looking at and have been a weak link in every motor they have ever been installed into. The crank and rods are beefy in the LSA.

I don't need a sales pitch on Hyper pistons, I have been around enough cars to know that they are way above their pay grade in this type of engine.

[jrboyd_1980]

Originally Posted by KoTToN

also please add some wings and a jetpack, besides being a modified race car they will also be bi-planes!

Also can you make a flight attendant mandatory along with the trunk monkey? Would like to have drinks will taking a flight on my modified race car biplane.