Tuning An Ls2 Engine Stand

We found an old LS2 block with scored cylinders, but Demirjian says various LS blocks would be suitable candidates. As he explained, "I like the LS1 block because it has solid main webs with no cast-in breather holes. I will install the large bore, 4.200-inch sleeves in the LS1 blocks but not the LS6. The LS6 blocks have the cast-in breather holes making them too weak, in my opinion, to bore out for the larger bore sleeves. Now the Gen IV blocks also have breather holes but on these blocks the floor of the coolant section has been raised leaving more material for the sleeves to sit on, resulting in less chance of cracks developing compared to the LS6 block." The process of installing sleeves is an exercise in supertight tolerances. Bore centers must be held to within +/- 0.0005 inch. The bores themselves, for sleeve fitment, must be held to +/- 0.00025 inch, or a quarter of a thousandth of an inch! This is why having the right tools and skills are imperative.Demirjian has had blocks come in from various shops doing the installs dry that were six thousandths out of spec. In these cases the block couldn’t be saved and the only option was to pull the sleeves and install them in a correctly machined block.

If all of this sounds labor intensive, that’s only because it is. The basic charge to machine, stress relieve, install the sleeves, and deck the block is $1,175. Add in $100 to bore the block to within honing range and another $75 if you want the notches cut for rod clearance. The sleeves retail right around $1,300 and when you add it all up, you’re at $2,650 for parts and labor. Of course, you have to factor in the cost of the block, but good used donors can be found for around $400 (give or take). That means the total for a big-bore aluminum small-block would be a hair over $3,000. Not cheap, but very competitive to the aftermarket LS blocks that are currently available.

  • Tuning An Ls2 Engine Chain
    With the rotating assemble installed we went ahead and installed our sprockets and timing chain using some ARP fasteners. For this application we’re running a 24x reluctor wheel along with a 1x cam sprocket. Before building any LS engine you need to decide which electronics you’ll be using so you have the correct internal parts.
    With the rotating assemble installed we went ahead and installed our sprockets and timing
  • Tuning An Ls2 Engine Oil Pan
    This engine will eventually find a home in an early Chevy and to clear the frame we wanted a pan with ample clearance. This pan from Canton (PN 13-270A, $540) was the only one we found that would work in place of the F-body (’98-plus) pan commonly used in LS swaps. It has a 6.5-quart capacity and features a fully fabricated and baffled aluminum construction. As a bonus, it uses the OEM windage tray (GM PN 12558253) and F-body pickup (GM PN 12558251). To make sure everything cleared we bolted on the pan with a GM gasket and spun the rotating assembly.
    This engine will eventually find a home in an early Chevy and to clear the frame we wanted
  • Tuning An Ls2 Engine Bolts
    What we found was that the farthest forward pair of rod bolts just barely touched the pan. To remedy this problem we marked the bolts, removed them, and then knocked off the edges with a grinding wheel. We also spaced the windage tray away from the crank with three washers at each attachment point.
    What we found was that the farthest forward pair of rod bolts just barely touched the pan.
  • Tuning An Ls2 Engine Gm Pan
    We decided to run a factory GM pan on the dyno to save us the hassle of running remote oil lines for the Canton pan. After the dyno the trapdoor-baffled Canton pan will go back on.
    We decided to run a factory GM pan on the dyno to save us the hassle of running remote oil
  • Tuning An Ls2 Engine Lifters
    Before setting the heads in place we installed our COMP High Energy lifters (850-16, $210) using GM plastic lifter trays.
    Before setting the heads in place we installed our COMP High Energy lifters (850-16, $210)
  • Tuning An Ls2 Engine Heads
    Like a stereo system needs good speakers to perform, a short-block needs to be topped off with a set of killer heads. For this build we went with a set of some of the best cathedral ports on the market, Trick Flow GenX Street/Strip 235 cylinder heads. The big 235cc intake ports should feed our 454 plenty of atmosphere and they are designed for large-bore (4.125 inches and up) LS engines. The 70cc combustion chambers are CNC-profiled so that intake valves are unshrouded. This equates to more airflow and better combustion. At 0.600 of valve lift these flow 340 cfm on the intake side and 270 cfm on the exhaust side. They came assembled and ready to bolt in place with stainless 2.08-inch intake and 1.60-inch exhaust valves.
    Like a stereo system needs good speakers to perform, a short-block needs to be topped off
  • Tuning An Ls2 Engine Heads
    We then installed the heads using off-the-shelf GM head gaskets (PN 12582179) and ARP head studs (PN 234-4317). The GM MLS gaskets will have a compressed height of 0.051 inch.
    We then installed the heads using off-the-shelf GM head gaskets (PN 12582179) and ARP head
  • Tuning An Ls2 Engine Rocker Arms
    To complete our valvetrain, we went with a set of COMP Ultra Gold aluminum rocker arms (PN 19024-16, $460). These CNC machined rockers are some the of best COMP offers and won’t fail when pushed hard. For pushrods we ran COMP Hi-Techs (PN 7956, $135) with a length of 7.450 inches.
    To complete our valvetrain, we went with a set of COMP Ultra Gold aluminum rocker arms (PN
  • Tuning An Ls2 Engine Intake
    To top off our long-block we chose a 102mm intake from FAST (PN 146302, $950). This should be able to easily feed our 454 LS enough air. Its polymer construction equates to lightweight and improved heat dissipation. It’s also modular, which makes port matching it a snap if you’re so inclined.
    To top off our long-block we chose a 102mm intake from FAST (PN 146302, $950). This should