While on a trip to Ohio, we had the opportunity to visit Trick Flow Specialties' manufacturing center, near parent company Summit Racing Equipment's headquarters in Tallmadge, Ohio. General Manager Mike Downs showed the steps involved in designing and making cylinder heads from start to finish. We geeked out because we love seeing how things are made, and we are assuming you do too.
1. The design for a cylinder head starts on a computer. Engineers can use design drawings provided by the manufacturers, or they can use an existing part and plot the key elements with a coordinate-measuring machine. With the basic design digitized, they can machine model parts out of wood or urethane blocks. This is a urethane head, and the CMM can be seen in the background.
2. The models are flow tested to see if the design needs to be modified using two part epoxy as seen in the intake port (top photo). Some models, like the small-block Ford intake manifold, even end up on the engine dyno. Downs said that though machined from a block of wood (spray painted to look like aluminum), it survived three power pulls on their engine dyno before it started leaking water.
3. The models are flow tested to see if the design needs to be modified using two part epoxy as seen in the intake port (top photo). Some models, like the small-block Ford intake manifold, even end up on the engine dyno. Downs said that though machined from a block of wood (spray painted to look like aluminum), it survived three power pulls on their engine dyno before it started leaking water.
4. When the design is approved, casting molds are made by the pattern makers, based on the design software. They decide where parting lines need to be and how the core boxes are most efficiently designed. Core boxes are made out of a variety of materials including cast iron, billet aluminum, and urethane.
5. The core boxes are filled with a sand/epoxy mix to create the casting molds. This is the mold for a small-block Ford cylinder head. You may be wondering how the sand gets out of the parts once they're cast. After casting, the raw parts literally have the sand shaken out on a bouncing conveyor belt.
6. The molds are then shipped to foundries within the U.S. that cast the parts and ship them back to TFS, where they are machined and assembled in-house.
7. The parts first receive a rough machining: the decks and intake and exhaust port faces are surfaced and all sharp edges are deburred and the casting flash is ground off. If they are destined to be sold as TFS' line of Fast-As-Cast, they are then assembled and prepped for shipping.
8. Some of Trick Flow's heads are sold fully CNC ported, and those operations are done on one of the company's four Fadal 5-axis CNC machines.
9. Downs was especially pleased to show us the company's new Deckel 5-axis machine, which cuts at twice the speed of the Fadal machines while maintaining 100 percent of their accuracy. Here it is in action machining an LS3 head.
10. Once machined, the cylinder heads get a valve job and are assembled by hand using name-brand parts like PAC springs. They are then boxed and shipped from this facility too.
11. Pre-production parts, like these yet-to-be-released LS7 heads, are subjected to a rigorous 40-hour session on TFS' engine dynometer. The testing is generally done in 10-hour sessions and include dozens of full-load power pulls and several part-throttle, partial load pulls from 2,000–3,500 rpm, which Downs referred to as "climbing a hill." By running the engine at differing loads and speeds, they can replicate real-world driving conditions and expose problems like seat and guide wear that can occur during the lifetime of the part. Downs told us the heads are partially disassembled and inspected after every 10 hours of testing. Other parts are sliced apart on a bandsaw, checking for accuracy in deck-surface thickness and bolt-hole depth. "We aren't the fastest company to bring products to market," Downs said, "but when we do, we know it will last and do what it's supposed to."
Trick Flow Specialties
1248 Southeast Avenue