Trick Flow Cylinder Head & Camshaft Issues
Do you have a set of Trick Flow’s 2V cylinder heads installed on your two valve Modular V8? Having issues with properly tuning your setup? Not seeing the power numbers you were expecting? If so, you are most likely experiencing a valve train geometry issue as a result of a peculiar engineering decision made during the creation of the TFS 2V cylinder heads.
Trick Flow's Design Change to Ford's PI Cylinder Heads
Ford PI cylinder heads (Left) vs Trick Flow TFS-FMOD-1 cylinder heads (Right). Trick Flow relocated the intake valves in order to allow for higher lift camshafts and air flow rates.
The original Ford PI cylinder head design essentially cannot be modified satisfactorily in order to increase performance due to the port alignment to valve. Any significant modifications would require re-engineering the Ford PI head from scratch. In order to allow for more airflow, Trick Flow switched the angle on the intake valves and placed them in line with the intake port. The intended result was higher flow numbers and more horsepower over the stock Ford PI heads, but the unattended result was a slight change in the geometry for the valve train.
Pivot locations on the Trick Flow 2v TFS-FMOD-1 cylinder head. Note the pivots for the exhaust and intake are no longer on the same side.
Designing a camshaft requires certain cylinder head design aspects to be taken into consideration. Valve train geometry i.e., follower radius, 2 different rocker lengths, cam center to pivot center, cam center to follower/roller center are required to calculate and design a correct camshaft lobe to obtain correct valve action. Rocker arm pivot location, right or left of cam center must be known in order to design the camshaft. Pivot location has a major influence in cam lobe design.. When Trick Flow designed the TFS heads they did not take into consideration what the change of pivot location and geometry of the intake valves would have on overall camshaft/valve timing.
Pivot differences between the stock Ford PI cylinder head and the aftermarket Trick Flow TFS-FMOD-1 cylinder head.
In the figure above you can see the pivot differences between the Stock Ford PI cylinder head and the aftermarket Trick Flow 2 valve cylinder head. Exhaust timing remains unchanged between the two sets of cylinder heads while the intake timing is skewed due to its pivot and valve position being modified to accommodate Trick Flow’s design requirements.
Performance Issues from Bad Design
The intake pivot switch effectively modifies the intake timing and duration of the intake lobe profile on the camshaft. Take note, since the stock exhaust pivots remain the timing is unaffected on the exhaust side.
The first issue is the design of the Trick Flow TFS cylinder head and the location of the intake rocker arm pivots. By switching the side of the pivot and not compensating for the change in the camshaft intake lobe profile design, duration at 0.050 is out of phase of where it should be on a stock Ford PI head; this also offsets the lobe separation angle by a few degrees. What does this mean? Any stock ford PI camshaft in a Trick Flow TFS cylinder head will be out of specification and suffer from asymmetrical valve train action.
The second issue is manufacturing based. When a camshaft design is sent to a CNC grinder, the operator will need to specify the required LSA in order for the intake and exhaust lobes to be properly in phase to one another. A Ford PI camshaft for a Ford PI cylinder head may have a LSA of 114 degrees while a camshaft for a Trick Flow TFS cylinder head requires a LSA of retarded on one side and advanced on the other side to get 114 degrees at the valve. This means a camshaft for a PI head and a Trick Flow 2 valve head are two separate entities of LSA and camshaft lobe grinds all together.
- A camshaft made for a Ford PI cylinder head will not work properly in a Trick Flow 2 valve cylinder head
- A camshaft made for Trick Flow 2 valve cylinder head will not work properly in a stock Ford PI cylinder head
- The camshafts are not interchangeable between the two cylinder head designs. A new camshaft needs to be designed and manufactured specifically for the Trick Flow TFS 2V cylinder head
Data Comparison of a Camshaft Designed for a PI Head Installed in PI & TFS Heads
Below is the analysis of a set of camshafts designed for a stock Ford PI head installed in both a Ford PI cylinder head and an aftermarket Trick Flow TFS cylinder head. The first set of tables describes the overall event characteristics of the camshafts as installed in both types of heads.
| Left Side Head | |||
|---|---|---|---|
| 60055LC PI Head | 60055LC TFS Head | ||
| OVERALL EVENT | OVERALL EVENT | ||
| 202.25° @ 0.200 | 202.25° @ 0.200 | ||
| 217.11° @ 0.150 | 217.11° @ 0.150 | ||
| 233.16° @ 0.100 | 233.16° @ 0.100 | ||
| 252.66° @ 0.050 | 252.66° @ 0.050 | ||
| 270.16° @ 0.020 | 270.15° @ 0.020 | ||
| 286.98° @ 0.006 | 286.98° @ 0.006 | ||
| 292.39° @ 0.004 | 292.40° @ 0.004 | ||
| 114° Centerline with a LSA of 114° | |||
| Right Side Head | |||
|---|---|---|---|
| 60055RC PI Head | 60055RC TFS Head | ||
| OVERALL EVENT | OVERALL EVENT | ||
| 205.51° @ 0.200 | 205.51° @ 0.200 | ||
| 220.49° @ 0.150 | 220.49° @ 0.150 | ||
| 236.63° @ 0.100 | 236.63° @ 0.100 | ||
| 256.19° @ 0.050 | 256.19° @ 0.050 | ||
| 273.74° @ 0.020 | 273.74° @ 0.020 | ||
| 290.68° @ 0.006 | 290.68° @ 0.006 | ||
| 296.15° @ 0.004 | 296.16° @ 0.004 | ||
| 114° Centerline with a LSA of 114° | |||
The next table is the left head’s lift and duration as a function of crankshaft rotation. Both data ranges from the Ford PI and TFS cylinder heads are included.
| Left Side Head | |||
|---|---|---|---|
| 60055LC PI Head | 60055LC TFS Head | ||
| Cam Degrees | Cam Degrees | ||
| OUTPUT OPENING SIDE | OUTPUT CLOSING SIDE | OUTPUT OPENING SIDE | OUTPUT CLOSING SIDE |
| 50.17° @ 0.2000 | 50.96° @ 0.2000 | 46.42° @ 0.2000 | 54.71° @ 0.2000 |
| 53.88° @ 0.1500 | 54.67° @ 0.1500 | 49.82° @ 0.1500 | 58.74° @ 0.1500 |
| 57.91° @ 0.1000 | 58.67° @ 0.1000 | 53.57° @ 0.1000 | 63.01° @ 0.1000 |
| 62.82° @ 0.0500 | 63.51° @ 0.0500 | 58.26° @ 0.0500 | 68.07° @ 0.0500 |
| 67.23° @ 0.0200 | 67.85° @ 0.0200 | 62.55° @ 0.0200 | 72.52° @ 0.0200 |
| 71.38° @ 0.0060 | 72.11° @ 0.0060 | 66.66° @ 0.0060 | 76.84° @ 0.0060 |
| 72.61° @ 0.0040 | 73.59° @ 0.0040 | 67.88° @ 0.0040 | 78.32° @ 0.0040 |
| Event = 85° | Event = 90° | Event = 80° | Event = 94° |
Lift and duration data from the right set of heads included below.
| Right Side Head | |||
|---|---|---|---|
| 60055RC PI Head | 60055RC TFS Head | ||
| Cam Degrees | Cam Degrees | ||
| OUTPUT OPENING SIDE | OUTPUT CLOSING SIDE | OUTPUT OPENING SIDE | OUTPUT CLOSING SIDE |
| 51.49° @ 0.2000 | 51.26° @ 0.2000 | 55.25° @ 0.2000 | 47.51° @ 0.2000 |
| 55.22° @ 0.1500 | 55.03° @ 0.1500 | 59.29° @ 0.1500 | 50.96° @ 0.1500 |
| 59.22° @ 0.1000 | 59.09° @ 0.1000 | 63.57° @ 0.1000 | 54.75° @ 0.1000 |
| 64.05° @ 0.0500 | 64.05° @ 0.0500 | 68.62° @ 0.0500 | 59.48° @ 0.0500 |
| 68.33° @ 0.0200 | 68.54° @ 0.0200 | 73.02° @ 0.0200 | 63.85° @ 0.0200 |
| 72.35° @ 0.0060 | 72.99° @ 0.0060 | 77.08° @ 0.0060 | 68.26° @ 0.0060 |
| 73.54° @ 0.0040 | 74.54° @ 0.0040 | 78.28° @ 0.0040 | 69.80° @ 0.0040 |
| Event = 85° | Event = 91° | Event = 90° | Event = 86° |
Proper center-line for a camshaft designed for a PI head installed into a PI head. This data is for the right side cylinder head.
| Right Side Head | ||
|---|---|---|
| 60055RC PI Head | ||
| Crankshaft Degrees | ||
| OUTPUT OPENING SIDE | OUTPUT CLOSING SIDE | ACTUAL CENTERLINE |
| 102.98° @ 0.200 | 102.52° @ 0.200 | 113.77 |
| 110.44° @ 0.150 | 110.06° @ 0.150 | 113.81 |
| 118.44° @ 0.100 | 118.18° @ 0.100 | 113.87 |
| 128.10° @ 0.050 | 128.10° @ 0.050 | 114.00 |
| 136.66° @ 0.020 | 137.08° @ 0.020 | 114.21 |
| 144.70° @ 0.006 | 145.98° @ 0.006 | 114.64 |
| 147.08° @ 0.004 | 149.08° @ 0.004 | 115.00 |
Data from a camshaft designed for Ford PI cylinder head as installed in a TFS aftermarket cylinder head. There is a 10 degree difference in center-line from the proper configuration. This data is for the right side cylinder head.
| Right Side Head | ||
|---|---|---|
| 60055RC TFS Head | ||
| Crankshaft Degrees | ||
| OUTPUT OPENING SIDE | OUTPUT CLOSING SIDE | INSTALLED CENTERLINE |
| 110.50° @ 0.200 | 95.02° @ 0.200 | 103.26 |
| 118.58° @ 0.150 | 101.92° @ 0.150 | 102.67 |
| 127.14° @ 0.100 | 109.50° @ 0.100 | 102.18 |
| 137.24° @ 0.050 | 118.96° @ 0.050 | 101.86 |
| 146.04° @ 0.020 | 127.70° @ 0.020 | 101.83 |
| 154.16° @ 0.006 | 136.52° @ 0.006 | 102.18 |
| 156.56° @ 0.004 | 139.60° @ 0.004 | 102.52 |
Proper center-line configuration for a stock set of PI cylinder heads and camshaft. Repeated for the left cylinder heads.
| Left Side Head | ||
|---|---|---|
| 60055LC PI Head | ||
| Crankshaft Degrees | ||
| OUTPUT OPENING SIDE | OUTPUT CLOSING SIDE | ACTUAL CENTERLINE |
| 100.34° @ 0.200 | 101.92° @ 0.200 | 114.79 |
| 107.76° @ 0.150 | 109.34° @ 0.150 | 114.79 |
| 115.82° @ 0.100 | 117.34° @ 0.100 | 114.76 |
| 125.64° @ 0.050 | 127.02° @ 0.050 | 114.69 |
| 134.46° @ 0.020 | 135.70° @ 0.020 | 114.62 |
| 142.76° @ 0.006 | 144.22° @ 0.006 | 114.73 |
| 145.22° @ 0.004 | 147.18° @ 0.004 | 114.98 |
Again a 10 degree difference in center line position. Repeated for the left cylinder head.
| Left Side Head | ||
|---|---|---|
| 60055LC TFS Head | ||
| Crankshaft Degrees | ||
| OUTPUT OPENING SIDE | OUTPUT CLOSING SIDE | INSTALLED CENTERLINE |
| 92.84° @ 0.200 | 109.42° @ 0.200 | 125.29 |
| 99.64° @ 0.150 | 117.48° @ 0.150 | 125.92 |
| 107.14° @ 0.100 | 126.02° @ 0.100 | 126.44 |
| 116.52° @ 0.050 | 136.14° @ 0.050 | 126.81 |
| 125.10° @ 0.020 | 145.04° @ 0.020 | 126.97 |
| 133.32° @ 0.006 | 153.68° @ 0.006 | 127.18 |
| 135.76° @ 0.004 | 156.64° @ 0.004 | 127.44 |
Our Solution
If you have a set of Trick Flow 2 valves heads with improper camshafts, you will need a new set of camshafts that match the head setup manufactured. We have extensive experience with this issue and have camshaft lobe profiles on file that work perfectly with the Trick Flow TFS cylinder heads. We have modified the Ford PI camshaft design to allow for the relocated pivots while providing additional lift. We were the first to identify the issue and first to implement a correct solution. Call or email us today to get your lost performance out of the Trick Flow heads.