Muscle Mustangs & Fast Fords
Livernois Motorsports Heads and Cams On A Stock Modular Engine - Top Shelf Shuffle
Making 451 Hp With Livernois Motorsports CNC-Ported Heads And Cams.
In addition to locking out the VCT, we swapped on a new set of CNC-ported heads (done in-house at Livernois) and then upgraded to new cams with the VCT lockouts. Schropp and his staff showed off the capabilities of its parts and pieces on the in-house engine dyno. They first dyno'd a bone-stock Three-Valve engine that serves as an R&D tool. In stock trim, with just a set of long-tube Kooks headers, the engine produced 313 hp at 5,500 rpm, while torque came in at 314 lb-ft at 4,300 rpm.
Did Ford underrate the engine, since we saw 313 hp? In all fairness, the 300 number is probably close. Remember, our dyno engine wore a set of long-tube headers, which probably hurt a little in stock trim. But more importantly, we ran without the accessories like A/C, power steering, and alternator. Another deviation from stock was that this engine was run with an open throttle body thanks to the FAST XFI fuel injection system. No restrictive inlet tubes or MAF sensor to contend with, and the computer had a custom tune. The VCT was also locked out. So it was slightly better than the way Ford tests its engines.
We chose to swap out the heads first and keep the camshafts stock. A change in bumpsticks would follow for a combined power gain. Changing heads on an engine while on the dyno is ridiculously easy. The Livernois staff worked quickly as one guy per side made the process go twice as fast. It seemed like an instant that the new heads were on the engine and the test mule was blasting through the rpm range again. The Livernois Stage 3 CNC-ported heads are available for the ripe sum of $2,899, including the cylinder head castings. Stage 3 heads are capable of flowing a max of 300 cfm through the intake ports, while the single exhaust port moves 215 cfm. Intake valves are custom units that check in at 35mm. On the exhaust, the inconel pieces are 38mm. Some pushrod enthusiasts might be wondering why the exhaust valve is bigger-it's because the intake has two 35mm valves per cylinder. It's no wonder we have seen 8-second capable Three-Valve modular engines with ported stock heads.
Adding Livernois heads to the stock short-block netted us over a 100 horsepower gain-on the engine dyno. Power shot up to 420 at 6,100 rpm while torque got a shot in the arm by going to 354 lb-ft at 5,200. As you can see, peak rpm for both torque and horsepower increased greatly. This is due to the better breathing cylinder heads, as they moved the powerband since the engine was able to breath easier in the upper rpm ranges. The engine was at the limit of the stock camshafts, and Livernois had a pair of Comp Stage 4 cams waiting to be installed to remedy the problem.
Like we mentioned earlier, Livernois prefers to completely lockout the VCT actions. A simple block that Livernois produces handles the task. "The lockouts put the cam in the neutral position. This is the position that the spring on the front of the phaser wraps the cam gear into naturally. By locking the phaser out, you have a little more control over what camshaft profile you want to run," said Scrhopp. Eliminating the VCT removes the chance of failure, and allows for a custom profile camshaft to be dialed in exactly where the engine builder wants it for max power. "The factory camshafts have a different lobe profile that allows them to work in conjuction with the phasing system. Some aftermarket cams also carry this trend but do not work as well when the camshaft is locked out. This is where coming up with a profile that fits the engine without the VCT can allow for more room in the camshaft design."