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2010 Camaro SS Project Car - Happy Accident
We Turn Tragedy Into Triumph By Rebuilding Our Wounded Ls3 Into A 416 Stroker.
Jan 1, 2011
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2010 Camaro SS Project Car - Happy Accident
Like its fourth-gen cousin, the best way to remove the engine in a fifth-gen Camaro is to drop it out the bottom along with the entire cradle. That's not to say that you can't pull it out the top but, believe it or not, this is easier.
Feeling like a coroner, we investigated the internal parts to find what was causing our loss of compression. Nothing was broken, but most of the rings were eaten up. Since the amount of labor to replace the rings is close to the labor needed for a stroker, we decided to make the best of a bad break.
To ensure the rod bolts will clear the block, we needed to notch the block in eight strategic spots. We've done this a few times so we knew where to do it, but you could also install the parts, rotate the assembly, and make some marks.
We then set about file-fitting all of our new rings supplied with the Ross pistons. To make this tedious task a ton easier, we broke out our new Proform electric end gap filer (PN 66765). The unit is 12-volt rechargeable battery-powered and included two 120-grit grinding wheels.
Taking a 374 ci LS3 to 416 inches is pretty easy, since most of the new 42 ci comes from increasing the stroke to 4 inches. The bore just gets a nice cleanup hone to 4.070 inches.
Since we're running the Magnuson blower, we thought this would be a great time to lower the static compression of the LS3. From the factory it comes in at 10.7:1, so we contacted Ross Racing Pistons for some dished slugs. Their pistons are forged from 2618 billet bar stock and hardened to a T61 condition to better resist fatigue and keep its shape under extreme pressure and rpm. To get us near our 9.5:1 compression target, these pistons have a volume of -17.6cc. They also have a compression height of 1.112 and utilize a 0.927 pin.
When rotating assemblies fail it's typically the rods that let go, and given the stresses placed on connecting rods, it's no wonder. These Eagle ESP H-beam 6.125-inch rods (PN 612503D2000) are built to take whatever we throw at them. Their two-piece, forged, vacuum-degassed, 4340 steel construction provides strength while still weighing less than stock rods. Each rod is heat-treated, X-rayed, magnafluxed, and shot-peened to stress-relieve the metal. They come standard with ARP 2000 rod bolts.
Soon it was time to drop in the forged Eagle crank (PN 434740006100). Since it's for the '10, it came with the required 58x reluctor wheel. The 4340 crank features a non-twist forging, and Eagle put it though a multi-stage heat-treatment process. Like the rods, it's fully tested and shot-peened. For improved oiling, the crank was also cross-drilled and has chamfered oil holes. Other features like a 0.125-inch radius on the rod and main journals and micro-polishing just make a good crank even better.
With the new crank installed, we set the mains in place and torqued everything to spec. The crank came coated in Eagle's ESP Armor Shield, which has been shown to yield a few extra horsepower. To find out more check out Eagle's website.
Since the GT-9 cam utilizes the LS2 three-bolt cam bolt system, we needed the rest of the parts to do the swap. This included the 4x upper cam sprocket, cam retention plate (PN 12589016), cam retainer plate bolts (PN 11515756), chain dampener (PN 12588670), and three cam bolts. Next time we will think to ask if the cam comes in an LS3-friendly single-bolt configuration.
Before setting the new Eagle crank in place, we installed new Clevite bearings and coated everything in a thick layer of Royal Purple assembly lube. The original bearings looked to be in decent shape, but new ones aren't expensive, and using fresh bearings is never a bad idea.
Choosing the right cam can make or break a supercharged engine, so we grilled Andy Mages over at ADM Performance and he recommended a stick that COMP churns out for Lingenfelter. Their hydraulic GT9 cam has duration numbers (at 0.050) of 215/247, lift of 0.629/0.658 and a 121 lobe separation angle. This should result in killer performance from the LS3 heads and great idle characteristics.
Time for the fun part - popping in the pistons and rods. This task was made a ton easier by oiling up the cylinder walls and using a ring compression tool.
Before moving to the heads, we cleaned, lubed, and re-installed the roller lifters in the plastic GM lifter trays.
To keep costs and complexities down, we didn't mess with the GM LS3 heads. Besides, they flow pretty damn good right from the factory. For head gaskets, we simply hit up our local GM dealer for a set for factory MLS pieces.
Running a blower means we're going to have increased cylinder pressure. To keep the heads where they belong, we picked up a head bolt kit from ARP (PN 134-3610).
To handle the extra lift of our GT-9 camshaft, Andy at ADM suggested we upgrade the springs to these Patriot Xtreme 0.660-inch pieces (PN 8501). The kit came with locks, seals, bases, and titanium retainers.
And just like that, our new forged long-block was done and ready to go back into our '10 SS. Best of all, from the outside it looks like any other stock LS3.
While reinstalling the LS3, we thought it was the perfect time to add this hose relocation kit from TechAFX. On the functional side, the kit has a new fuel and EVAP line made to OEM standards. The fuel hose was tested to 150 psi and looks great. The heater hose kit really dresses up the engine bay if you're not running the big plastic engine cover. It helps ditch the ugly rubber heater hoses GM tossed on top of the LS3 and replaces them with CNC-bent and formed aluminum tubing and custom-formed, 90-degree rubber ends.
We figured, "Who better to tune our Magnacharger-equipped Camaro than the guys over at Magnuson products?" Andrew Zimmer strapped down the SS and did a few pulls.
With the engine back in place, you would be hard pressed to find that our LS3 is now a 416 stroker. GM computers are amazingly adaptable, and the new engine fired right up. But before putting our foot in it, we knew it needed some tuning on the chassis dyno. Besides, we wanted to see what sort of power we gained.
What we found was that the 3.8-inch pulley we were running was way too big with new 9.5:1 compression engine. We eventually worked all the way down to this tiny 2.8-inch pulley.
It's good news, bad news time, except the bad news really isn't all that bad. After some tuning on 91-octane California swill, we knocked down an impressive 600.2 hp and 609.5 lb-ft of torque to the wheels. The problem we ran into was that, at around 4,000 rpm, the GM six-rib belt started to slip and drop boost. So, while we were hoping for about 9 pounds at 6,000 rpm, we were only getting 7 pounds. The fix is to pick up an eight-rib overdriven system from Innovators West. The extra ribs will support more horsepower and the 10-percent overdrive damper will let us run a bigger blower pulley, which will also increase grip. But that's another story for another day.
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