2010 Camaro SS Heads - 2010 Camaro: The Next Push

Once the heads were off and on the bench, we broke out a valve spring compressor. We removed the Mast springs (nitrided beehive, good for up to 0.650 lift) and retainers for use on the new Black Label heads-they match the Stage 1 Mast cam. Still, before swapping over always check the pressure of the springs (new or old) on a valve spring pressure checker before installing them onto new heads.

To install the Mast springs on the new heads, MM recommended the installed spring height needed to be 1.800 to 1.850-inch for proper spring load (130 pounds at 1.800-inch and 318 pounds at 1.200-inch). In order to obtain the necessary spring height, we placed different thickness (0.015, 0.030, 0.060-inch) shims and spring locators (stock and Mast) under the measuring tool. The retainer and locks were installed on the top of the tool and it was hand tightened to measure size. We needed to do this a few times until we arrived at the desired spring height.

Here's the assembly (left to right, bottom to top to assemble) we arrived at for proper spring height (1.850-inch) and pressure load. A 0.060-inch shim (Manley part number 03266-50), 0.062-inch Mast spring locator (PN 930-100), Mast valve seal, Mast beehive spring (PN 90-101), Mast titanium retainer (PN 931-100), and Mast 7-degree locks (PN 932-701).

To start assembly, we coated the valve tip with GM E.O.S. assembly lube before inserting the valve into the valve guide.

The valve spring assembly is installed as in the previous order shown. With the spring compressed, we place the locks into the groove near the valve tip. After completing the head assembly, we sprayed brake cleaner (gas, carb cleaner, or kerosene works) into the ports, making a puddle around the seats to check for leaks. Fortunately, there no leaks detected so we didn't have to lap the valves.

We installed new high-rev lifters from AC Delco (PN 17122490), which are really LS9/CTS-V lifters. Also notice the flat (no veins) lifter valley cover (from an LS2) to replace of the former DOD (Displacement On Demand) valley cover. We needed both the LS9 lifters and the LS2 valley cover to eliminate the DOD and valve float at high rpm (6,300-7,000 rpm).

Since the Mast heads are 0.750-inch taller, longer pushrods are needed. To determine the right pushrod length and proper lifter preload, we set down the head gasket and torqued the head to only 50 lb-ft. We placed an adjustable pushrod (set at roughly 0.750-inch longer than stock) between the new lifter and intake rocker arm (25 lb-ft torque) and turned the motor over by hand until we were at the base circle (no lift area) of the cam. We had to remove the rocker a few times to adjust the pushrod length to zero lifter preload. We also did this with the exhaust rocker.

At zero lash (zero lifter preload) the measurement of the adjustable pushrod turned out to be 8.021-inch in length. LS engines like between 0.070 to 0.090-inch lifter preload. So, by adding 0.079-inch length to our measurement, the needed pushrod would be 8.100-inch long for proper lifter preload using the stock net-lash rocker arm system. Pushrods are available only in 0.050-inch increment lengths. Different cam manufacturers have different base circles which can affect pushrod length. Always be careful to check pushrod length when swapping a cam.

Matt's father (Bart Hauffe) drove a few miles to Manley Performance in nearby Lakewood, New Jersey, to pick up the pushrods. On top is a stock length (7.400-inch) Manley pushrod that was installed during the cam swap in part 1. Below is the Manley pushrod (8.100-inch, PN 25722-16) we needed for our new combination. It features 0.080-inch wall, is made of 4130 chrome moly and is stronger than a stock pushrod.

We used GM Performance Parts head gaskets (4.080 bore MLS PN 12610046) before we put the new heads in place. The threads of the ARP head bolts (PN 134-3610) were coated with 30-weight oil and torqued to 80 lb-ft. The proper torque sequence was followed and performed in three steps: 40, 60 then 80 lb-ft. The heads look great at this point. It's too bad the beautiful Mast Motorsports script will be hidden by brackets, bolts, hoses and wires.

All of the new Manley pushrods were installed and we reused the stock rocker arms. Here the rockers are being torqued to the specs (25 lb-ft).

Once the motor was back together and running, it's hard to tell the new heads were installed. The Tune Time crew commented the valvetrain was the quietest they've heard. With the coil packs now sitting 3/4-inch higher, the ignition wires became taught.

The new F-body was strapped down to Tune Time's Mustang dynamometer. We needed to make a few easy pulls to be sure the A/F (air/fuel) was safe and there was no knock detected. The Mast heads were already showing us a 35 rwhp gain before Matt applied any tuning.

Matt's tuning skills are renowned in the Northeast. Here the tune-master does his thing and changes the necessary parameters to safely tune-in more power. With HP Tuners software in his laptop, he can alter and manipulate the fuel and spark tables-until the 6.2 can make its best average power at a safe A/F mixture ratio of 12.6 to 12.8. Dyno tuning was worth 11 rwhp to the new combination.

After tuning, the Mast Motorsports heads proved they were worth 46 rwhp and 22 lb-ft of torque (452 hp at 6,500 rpm and 400 lb-ft at 4,600 rpm). Peak torque was still at 4,600 rpm but peak power climbed up the ladder 200 rpm to broaden the power band. Looking at the dyno graph, you can see how power improved along the entire dyno pull. With these great gains, we were anxious to go to the track the next day.

Our track day was a washout and it poured for the next four days. This gave us time to have a custom set of LiveWires made by the folks at Performance Distributors...

...The left picture shows a proper-fitting plug wire with the stock heads (823 casting). The center shot shows the same wire too taut with the new Mast...

...heads (LSR casting). The right picture shows the longer length LiveWire (PN C9LS-MAST) needed for the 3/4-inch taller Mast heads.

Being horsepower junkies, we couldn't wait to try the new FAST LSXR 102mm intake manifold (PN 146102). It has show gains of 16 and 26 hp on 376ci and 500ci LS engines respectively. We saw a gain of 4 rwhp from 5,500 to 6,800 rpm. We lost an average of 8 horsepower from 2,500 to 5,000 rpm and decided to track test the car with the factory intake reinstalled. This is not an indictment of the FAST piece. We just didn't have enough engine to take advantage of it.

To lower the IAT (inlet air temperature), this SLP Blackwing air intake setup was borrowed from Matt's G8. The SLP unit pulls cooler air from the inside left front lower corner of the fender. With the previous setup, if the IAT was too hot (over 110-degrees), the MAF would pull out timing (4 to 8-degrees) causing a power loss (10 to 20hp). SLP and Tune Time are developing a new air intake for the '10 Camaro that should be available by the time you read this.

A week after our rain out, we hit the E-Town tarmac. We mounted a pair of Nitto NT555R drag radials (275/40R20, the OEM size) on the stock rims to ensure consistent hook. On our first pass we broke into the 11s. We were very excited to do it naturally aspirated. Our best run turned out to be an 11.81 at 119.27 mph. That's impressive considering our test weight (car and driver) of 4,050 pounds. The Mast Motorsports heads proved they are worth the work and expense. Flowing lots of air, they would be even more potent on a large displacement, and/or forced induction LS powerplant.