LY6 vs LS3 differences??

Discussion in 'High Tech Retrofits' started by Aceshigh, Nov 30, 2010.

  1. Aceshigh

    Aceshigh Veteran Member Lifetime Gold Member

    Messages:
    26,757
    Likes Received:
    6
    Joined:
    Apr 9, 2001
    Location:
    Boondocks
    What is the main differences between an LY6 and an LS3 ??
    LY6 = 6.0L with VVT, 9.6:1 Iron Block, Aluminum pistons, Powder rods
    LS3 = 6.2L no VVT, 10.5:1 Aluminum Block, cast hypereutectic aluminum/silicon alloy pistons, forged powder rods.

    I've seen 2 versions of LY6's out there. Van and Truck.
    Van = 323hp
    Truck = 352hp

    LS3 in the Corvette = 430hp
    You're talking nearly a 100hp difference from the Van LY6 to the Vette LS3.

    So what gives?? Is it just a tune between the factory Van and Truck motors?
    Also some guy was trying to say with an LS3 intake, injectors, and tune
    the LY6 puts down just about the same HP as the LS3. With all the
    differences I just can't see it being the same without sacrificing efficiency.

    Thoughts??
     
    Last edited: Nov 30, 2010
  2. sceld71

    sceld71 Veteran Member

    Messages:
    1,067
    Likes Received:
    0
    Joined:
    Nov 9, 2005
    Location:
    Plain City, Ohio
    I was wondering the same thing with the LM7. So, what is the difference?
     
  3. daniel76309

    daniel76309 Veteran Member Lifetime Gold Member

    Messages:
    935
    Likes Received:
    7
    Joined:
    Oct 22, 2005
    Location:
    Niceville, Florida
    I'm no expert, but after looking into options prior to going with the LS3, this is my take on it. IIRC I think the CR on the LS3 is 10.7:1. Either way, it is about a whole point of compression more, plus it has lighter valves. Both of those things work with a bigger cam, which I would guess is the most significant difference. Also, the intake and exhaust system on the LS3 are probably more conducive to hp rather than low end torque so that would affect the factory ratings as well.
     
  4. sceld71

    sceld71 Veteran Member

    Messages:
    1,067
    Likes Received:
    0
    Joined:
    Nov 9, 2005
    Location:
    Plain City, Ohio
    If I'm wrong somebody please correct me.
    LS3 is all aluminum with higher compression ratio.
    The other engines, LY6 and LM7 is cast iron with a lower ratio.

    But, LS3 intake and exhause will work. So, another words other than the weight difference. The LY6 and LM7 can be ran like the LS3 if you change the bore, heads, intake, and exhause. But, the LY6 and LM7 are half the price of the LS3 block.

    Thoughts?
     
  5. JAMMINJ007

    JAMMINJ007 Veteran Member

    Messages:
    397
    Likes Received:
    1
    Joined:
    Dec 27, 2005
    Location:
    Houston, Tx
    Cam and compression ratio. ly6 also smaller cubes. Mill the ly6 looking to gain at least 30hp. Change cam gain almost 100. I did just a cam swap and made 360 to the tires with a slipping trans would have been closer to 400rwhp. If I were to guess it will run low 12's or high 11's with nothing more than a cam swap and headers. Will find out later this month once I get my trans back. :)
     
  6. quadriderkyle

    quadriderkyle Member

    Messages:
    85
    Likes Received:
    0
    Joined:
    Jan 4, 2010
    Location:
    davenport iowa
    I thought that 6.0s all had cathedral ports and the 6.2s got the new rectangle ports. If I am not mistaken then there are significant differences and none of the top end parts will interchange without swapping them all. Not sure though, as I know nothing about the Ly6
     
  7. JAMMINJ007

    JAMMINJ007 Veteran Member

    Messages:
    397
    Likes Received:
    1
    Joined:
    Dec 27, 2005
    Location:
    Houston, Tx
    LY6 uses rectangular (L92) heads so not all 6.0s have cathedral. Everything will swap over.
     
  8. 70 gsconvt

    70 gsconvt Veteran Member

    Messages:
    1,095
    Likes Received:
    0
    Joined:
    Sep 30, 2009
    Location:
    Wadsworth, OH
    I've been researching these engines a lot also for my swap.

    Basically, unless you NEED an all aluminum engine, don't waste your money on the LS3. With the money you save on the engine purchase, you can have the heads ported, swap in a better cam and springs, and if you like, shave the heads to bump compression.

    Personally I'd leave the compression alone. It's more pump gas friendly and will lend itself to responding to the right cam to make the most torque. And after all, it's torque that moves a car quickly, not horsepower.
     
  9. 71RS/SS396

    71RS/SS396 Veteran Member

    Messages:
    2,624
    Likes Received:
    27
    Joined:
    Aug 26, 2008
    Location:
    Wake Forest NC
    Don't waste your money porting LS-3/L-92 heads. My engine builder did some testing on this and said the gains were minimal and didn't justify the cost for the gain. The money you save on not porting will help pay for your cam and valvetrain parts.
     
  10. daniel76309

    daniel76309 Veteran Member Lifetime Gold Member

    Messages:
    935
    Likes Received:
    7
    Joined:
    Oct 22, 2005
    Location:
    Niceville, Florida
    I guess it is a matter of perspective...

    I would say avoid the hassle and don't waste your money on changing intakes and oil pans, porting the heads, buying lightweight valves and heavier springs, an aftermarket cam, etc....save your money on all that stuff and just buy the LS3 in the first place.

    I went with the LS376-480 crate engine. It costs more up front, but has the following advantages:
    • It already has everything needed to make 480 hp. I don't have to experiment and hassle with cams, springs, valves, etc., and hope that it all works.
    • It also already has "car" intake, oil pain, etc., so I can avoid the hassle and expense changing out all of those things.
    • It is brand new from GM with a 2-year warranty.
    • It is all-aluminum, so about 65 pounds lighter (IIRC).
    • Since it is a GM crate engine, they make a controller package specifically designed for it, so no need to "tune". Whether you pay someone to tune professionally, or buy your own software and wide band O2 sensor and do it yourself, it gets pretty expensive. (Granted, I suppose a custom tune on a dyno might still help a little, but I would expect that the factory tune is pretty darn close to ideal--it DOES make 480 HP, after all.)
    The other side of it is that there is a sense of "adventure" in getting a used truck engine and making it work, but for me, I have more than enough other challenges with this swap to keep me occupied. Aces, I know you have already done this swap before, so you may see it differently than I do. That is why I say it is a matter of perspective.
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.