Getting A Head
How Total Engine Airflow produces the fastest heads in EFI Renegade
by Don Creason, 2002

Only a few years ago we couldn't even begin to imagine the amount of power our little 5.0 liter Fords could make. Now we take for granted the fact that we have such a variety of parts and technologies available to us to suit our every horsepower need. A key ingredient in that list of parts has always been cylinder heads. One of the leaders in cylinder head technology who have been making Fords faster for years is Total Engine Airflow.

Owner Brian Tooley started out at Holley years ago, helping to design cylinder heads and other induction pieces. In the mid 1990's Tooley struck out on his own to start Total Engine Airflow, taking his ideas about airflow, valvetrain geometry, and port design with him. Today his shop runs one of the few true five axis simultaneous CNC machines in the country for porting cylinder heads. TEA is the only street car head porter who creates their own CNC programs (we'll talk more about this a little later), and keeps everything in house. This operation is one of the most comprehensive in the business. In this article we're going to cover a few misconceptions about CNC work and how it's done along the way. We will also take a look at TEA's new Twisted Wedge EFI Renegade cylinder head for 2002.

Let's start by talking a little about what TEA has accomplished so far. They have some of the best flowing and fastest running cylinder heads on the market. Racers that have set numerous records, won championships. In fact in 2001 their customers won 14 of the 17 NMRA, Fun Ford and WFC Renegade races. Maybe you recognize some of the racers running TEA heads. Bart Tobener, Mike Freeman (first two Renegades to run 8's), Craig Zurman, Micheal Freedman, Bob Kurgan, and Mike Murillo are just a few.

CNC:
There are a lot of common misconceptions out there about CNC equipment. First, CNC machines are not created equally. TEA is using a Fadal five axis CNC machine. This machine is a true five axis simultaneous CNC, in that it moves every axis while cutting the piece. There are other 5 axis machines out there, however the forth and fifth axis are not able to move simultaneously with the other three axis. The Fadal allows TEA to create the highest quality, and most accurate CNC work possible. Secondly, and maybe the biggest misconception is that a CNC mill is a magic machine that any machinist can obtain great results with. Many don't understand that while the results from CNC machines do indeed seem magical, there are countless hours spent getting those results. "A guy stopped in here with a set of heads and ask to have them ported" Tooley says, "He had a set of cast-iron heads which I won't put on the CNC because I believe it's too hard on the machine. I told him we could do the work by hand, and he says "can't you just put them on the CNC machine? I already hand ported them." What he didn't understand was we didn't have a program for those heads. Furthermore we would have to correct any errors he might have made hand porting the heads himself. The guy thought he could port a set of heads at home as well as we can port them by hand, and that if they were CNC'ed they would be far better than what any body could do by hand. The fact is the piece that comes off of the machine can only be as good as the port it was modeled after. You can have a fully CNC ported head that doesn't flow well because the port that was digitized was inadequate to start with. There are two key elements to the entire process. #1 being able to develope ports that flow well and make power. #2, being able to reproduce those shapes and designs as accurately as possible.

For a CNC machine to work it must have a program loaded. This program tells the machine how to move the component and the cutter, what speed to turn the cutter, how much material to remove during each pass, at what angle and height the cutter should be... etc. As far as we know TEA is the only shop porting street car heads that creates it's own 5 axis simultanous CNC programs based on port development that takes place in house. No work is farmed out.

Creating a CNC program is no easy task. It starts with developing a port by hand. Yes that's right, even though your heads have been cut by the precision CNC process, the original piece was done by hand for the machine to copy. During the development process, TEA flows the head numerous times to ensure that they’re getting outstanding flow numbers within the desired lift range. It does the customer no good to run a class with limited camshaft (like Renegade or Pure Street) if his heads aren't flowing very well within that range. Once a cylinder head design is correct and producing satisfactory numbers on the flow bench, TEA then puts that head on the Renishaw Cyclone digitizer. What the digitizer does is trace every contour of the ports, and combustion chamber using a very sensitive probe. This probe feeds that data to a computer program, which eventually creates the tool path that the CNC uses. The beauty of this is that TEA might have several sets of hand ported heads each with unique flow characteristics. They digitize the best ports and combustion chamber to create the final program. This ensures the best flowing head possible. Once the simulation passes, a finalized CNC program is created. The digitization and CNC program creation alone takes anywhere from one to five working days to complete. The end result however makes for the most powerful product possible for their customers.

Before being shipped to the customer, the heads are flowed on their fully computerized Flowdata Flowbench to ensure quality. Finally, the valvetrain components are added if the customer is purchasing assembled heads.

The Heads:
Just when you thought they couldn't get any faster or the heads couldn't flow anymore, TEA has done it again. Tooley and his team have come up with some very trick Renegade heads for the coming season and they're guaranteed to shatter some records and cause a stir. "Even Trick Flow is telling me these heads shouldn't be able to flow these kinds of numbers... we're very excited about the coming race season to see what our customers will be able to do."

The heads you see on these pages are the end result of years of research and winning races on the part of TEA and it's customers. The 2000 EFI/R champion Bob Kurgan ran a set of Twisted Wedge heads from TEA, as well as a TEA ported Holley Systemax intake. The 2001 runner up and fastest EFI/R racer on the planet Bart Tobener has run a 8.928/150.30 using TEA Twisted Wedge heads. There are others out there running both the Twisted Wedge and Edelbrock TEA EFI/R heads, but they've asked not to be named so that they can come out this season and surprise everyone.

I had the opportunity to spend a day at TEA. Part of the day was spent with Brian going over the basics of the CNC and seeing how the digitizer works. The second part with Ron Warrick Sr. and Ron Warrick Jr. flowing some heads, taking a look at valve jobs and other parts. What's amazing about the 2002 heads is the side by side port comparison with the 2001 Heads. You would think by looking at the 2001 head that there couldn't possibly be room for improvement, but TEA has found a way. Follow the captions and pictures to get the rest of the scoop on these heads.

TEA Twisted Wedge Flow Chart:

	CNC 185		CNC 205		REN 205
Lift	Int	Ex	Int	Ex	Int	Ex
.100"	55	55	57	53	57	53
.200"	145	110	145	111	149	111
.300"	220	149	225	154	228	155
.400"	270	183	275	199	283	203
.500"	300	212	305	220	314	228
.600"	305	227	320	237	325	240