Back in the day, you could add a set of aftermarket heads, a bigger cam, and an intake manifold on a pushrod 5.0L and effectively double the power output. Although that sounds impressive, the base motor made a whopping 225 hp. (It’s amazing what was considered powerful in the ’80s and ’90s.) So what effect do heads and cams have on the latest 5.0L?
In 2010, MM&FF got its hands on an ’11 GT to customize for the SEMA show; this also gave us the ability to test parts. Our AMSOIL GT has been a great research and development tool, testing out many “first” products for the Coyote in the past 15 months.
Recently, the idea of adding a set of ported heads and larger aftermarket camshafts came up as a potential story, and the debate started on how the DOHC 5.0-liter would react. One side argues that improved airflow equals increased power. The other side states that Ford did such a great job maximizing the platform’s efficiency, there isn’t much to gain—at least, not when the cost is taken into account. After all, the engine operates above 100-percent volumetric efficiency through most of the rpm band.
Due to the complexity of the...
Due to the complexity of the installation, Chris Jones and the crew at Blow-By Racing started by unbolting the K-member, then they lifted the car off of the engine and transmission. This way everything is accessible, and saves time and knuckles.
We were left with a few questions. How would improved airflow through the already stout heads affect power and torque? What potential was there with the combination of larger cams and the variable cam timing? And how would it all be affected by boost? Well, there’s only one way to find out!
Our trip into the unknown started with a call to Total Engine Airflow (TEA). We have used TEA for some custom porting and cylinder head repair work in the past, and the Tallmadge, Ohio-based company is second to none. With a fresh set of stock castings, TEA went to work designing a CNC program for the Coyote heads.
When it came to camshafts, we had options. With Coyote camshaft technology still developing, we could have used a set of regrind cams, which are just that—stock camshafts reground with smaller base circles on each lobe allowing you to gain increases in lift and duration. The reduction of camshaft base circle usually means the lash adjusters need to be shimmed to make up for the material lost during machining on the camshafts. Our other option was to wait for a set of new billet shafts, and after talking with Comp Cams, we decided to do that.
1. Total Engine Airflow (TEA)...
1. Total Engine Airflow (TEA) sent us a set of CNC-ported Coyote cylinder head castings.
2. The ported castings aren’t...
2. The ported castings aren’t hogged out due the high level of efficiency from the factory. They are massaged to improve airflow, and the runners are only 5cc larger.
3. You can see the stock...
3. You can see the stock runners aren’t much smaller, but the port work is evident in the flow numbers.
4. TEA also installed a set...
4. TEA also installed a set of heavier valve-springs. The beehive-style springs will be available from Trick Flow Specialties (PN TFS-16801-32) and have 80 in-lb of pressure on the seat. Pressure increases to 180 pounds when opened 1 inch.
5. The stock camshafts measure...
5. The stock camshafts measure 12mm lift (0.472-inch) on the intake side and 11mm lift (0.433-inch) on the exhaust side. The advertised duration is 260/263 degrees respectively.
6. With the front cover removed,...
6. With the front cover removed, the timing chains and tensioners are unbolted. The timing chains are similar to the older Four-Valves.
7. Our GT only has 1,331...
7. Our GT only has 1,331 miles on the odometer, and it was evident when the stock heads were removed. It looked like it was just assembled, with pronounced crosshatch marks and barely any carbon on the pistons. We could even see all of the laser-etched markings on the pistons from Ford.
8. Once everything was cleaned...
8. Once everything was cleaned and free of oil and coolant, we were ready to begin reassembling the engine. Cometic Gaskets sent us a set of its multi-layer steel (MLS) gaskets for the new DOHC 5.0-liter.
9. The gaskets have three...
9. The gaskets have three layers of steel, and once compressed under the cylinder heads, have the same thickness as the stock head gaskets, which means compression will not be affected.
10. Jones and Rob Vargo lower...
10. Jones and Rob Vargo lower the CNC-ported casting on to the stock short-block, and tighten everything with a set of head bolts from Ford Racing Performance Parts. The heads are torqued in four steps: 18 lb-ft, followed by 30 lb-ft, then two rounds of 90-degree rotation.
11. After applying a generous...
11. After applying a generous amount of assembly lube, Jones lowers the new Comp Cams into position. The new shafts measure 0.492-inch lift on the intake cam and 0.453-inch lift on the exhaust side. Duration is 228/235 at 0.050 respectively.
12. Comp Cams also sent is...
12. Comp Cams also sent is a set of its Cam Phaser Limiters to ensure there are no piston-to-valve clearance issues. The limiters are precisely machined pieces of aluminum designed to limit the amount of travel in the cam adjusters.
13. The limiters are installed...
13. The limiters are installed in the cam gears. With the cover removed, you can see how the cams are adjusted in relation to the cam gear.
Comp Cams offers six different off-the-shelf grinds for the Coyote—three for naturally aspirated combinations and three for boost. After multiple anonymous calls to the Comp Cams tech line for advice, we opted for the mid-level boost cams. The new shafts measure in at 0.493-inch lift on the intake cam, 0.452-inch lift on the exhaust cam, and duration is 228/235 degrees at 0.050-inch lift respectively. The Copperhead ECU controls the advance and retard of the cams to optimize power and efficiency.
In stock trim, the cams have a 50-degree swing (from 81 to 131 degrees of crankshaft rotation). The purpose of this is to advance the cams for low-end torque, but retard the cams for high-rpm power.
While this works well with the stock camshaft, higher lift and longer duration, coupled with the independent adjustability of the cams can cause piston-to-valve clearance issues. To remedy this, Comp Cams sells its Cam Phaser Limiters, precisely machined blocks that are inserted in the adjustable cam gears, limiting the amount of adjustability in each camshaft. Comp’s Phaser Limiters still allow for the ECU to advance and retard the cams independently, but the range is reduced so piston-to-valve clearance isn’t an issue. The limiters reduce the amount of advance and retard from 50 degrees of total rotation to 25 degrees of rotation (12.5 cam degrees).
14. The limiters are dropped...
14. The limiters are dropped into the oil-filled slots to limit the amount of travel for camshaft, thereby preventing any piston-to-valve clearance issues.
When it came to the cylinder heads, TEA used its CNC machine to open the intake and exhaust ports. The stock intake ports measure 193 cc; TEA opens then to 198 cc. "The CNC program is designed to improve airflow," explains Mike Downs, manufacturing manager for Total Engine Airflow. "The ports are opened about 5 cc, which isn’t huge. The design comes from everything we’ve learned in the Two-, Three-, and Four-Valve mod motors."
Swapping heads on a Coyote is not an afternoon project. The easiest way to handle the job is by removing the engine. For this, we headed to Blow-By Racing in Boca Raton, Florida, where Chris Jones and his team know the ins and outs of the Coyote. They started by removing the driveshaft, disconnecting the transmission shifter cable and electrical connections, removing the exhaust, and unbolting the BMR K-member. The body of our AMSOIL GT was then lifted off of the engine and trans, giving us all the room we could ever need to perform the swap.
Follow along as we swap the stock heads and camshafts for ported castings from TEA and larger camshafts from Comp Cams, and check back next month when we strap the AMSOIL GT to the rollers our Dynojet and hit the track.
Flow Numbers
| | Stock Coyote Heads | Total Engine Airflow Ported Heads |
| Lift (Inches) | Intake (CFM) | Exhaust (CFM) | Intake (CFM) | Exhaust (CFM) |
| 0.100 | 49.4 | 32.1 | 89.6 | 80.4 |
| 0.200 | 180.2 | 147.8 | 170.3 | 165.2 |
| 0.300 | 243.5 | 180.0 | 241.1 | 211.2 |
| 0.400 | 280.0 | 189.7 | 291.5 | 233.8 |
| 0.500 | 289.4 | 201.4 | 321.1 | 244.2 |
| 0.600 | 294.4 | 207.7 | 331.6 | 250.8 |
15. Being that we simply...
15. Being that we simply limited the cams and didn’t lock the variable cam timing out completely, the cams are installed in the stock location. Vargo lined up the marks on the gears and the secondary chains and installed the cam gears.
16. The primary chains are...
16. The primary chains are simply installed by lining up the marks on the cam gear and crank gear with the colored links in the timing chains.
16. The primary chains are...
16. The primary chains are simply installed by lining up the marks on the cam gear and crank gear with the colored links in the timing chains.
17. The chain tensioners...
17. The chain tensioners and sliders are reinstalled, and the installation of the camshafts is complete.
18. Cometic also supplied...
18. Cometic also supplied us with a set of its MLS header gaskets. Jones reinstalls our Kook’s Custom Headers long-tube headers with the Cometic gaskets.
19. While Vargo buttoned...
19. While Vargo buttoned up reassembling the engine, Jones went to work dropping the gas tank.
20. In our last attempt to...
20. In our last attempt to make big power, we were limited by our fuel system, or lack thereof. Looking for more power, we installed Blow-By Racing Jackal Fuel System, which will supply all the fuel we need for big power. The base of the kit is an Aeromotive A1000 fuel pump, which BBR modifies to work in the ’11-’12 gas tank.
21. The pump has a single...
21. The pump has a single AN -8 feed and a single -6 return. This means we will have to plumb new lines.
22. The fuel level sending...
22. The fuel level sending unit is removed from the stock fuel hat and attached to the new pump. Make two wire connections and the stock fuel gauge works without any issues.
23. Another cool feature...
23. Another cool feature of the Jackal system is that it still pulls fuel from both side of the stock gas tank. The crossover tube is attached to the new pump, and it works like a stock pump.
24. Up front, Jones installed...
24. Up front, Jones installed a set of Aeromotive billet fuel rails for the Coyote. For now we will reuse the 47-lb/hr injectors we already have.
25. The last step was to...
25. The last step was to fill the engine with eight fresh quarts of AMSOIL synthetic lubricant. Check back next month when we strap the AMSOIL GT to our Dynojet to see what kind of gains are available from ported cylinder heads and larger camshafts. We will also see what it equates to at the track! See you then.