Upgrading Cylinder Heads - Stepping Up To The Port - CNC Twisted Wedges
Out Of The Box Isn't Just Stock At Trick Flow Anymore. Now It Offers CNC Twisted Wedges, And We Tested Them
In 1995, Trick Flow debuted the much-anticipated Twisted Wedge small-block Ford cylinder head. With a low intro-ductory price and a revolutionary combustion chamber design, the Trick Flow Twisted Wedge head broke new ground. It was like a bomb going off in the 5.0 Mustang world as the level of cylinder head performance offered to the aftermarket performance public took a huge step forward. Ten years later, Trick Flow is back with its next ground-breaking design-a CNC-ported version of its landmark Twisted Wedge head that is sure to give the competition something to worry about while providing small-block Ford junkies a whole new horsepower fix.
The timing of this new release comes as several companies-both established and new-are moving into the high-performance Ford market with competitive cylinder head offerings. We lost count years ago of how many heads one can choose from when it comes time to build your next motor, but there are at least 40 different heads out there. It's no surprise Trick Flow has more competition today than in 1995, but until now it has never offered a factory-ported version.
"The market is driving us to do this head," says Charlie Schmidt, Trick Flow's lead sales representative. "It's gotten to the point that we were forced to offer the CNC port work from the factory. Brodix, Dart, AFR, and Edelbrock all have their version of a CNC-ported head, and we had to offer this head as well."
We first learned about this head at the PRI show, and anxiously awaited its release while we picked up information on final details. Trick Flow worked with its own engineers to design a ported version of the Twisted Wedge that would emphasize mid-lift numbers-already a strong suit with the stock castings. The ported versions include a full port of the intake and exhaust ports as well as a completely worked combustion chamber. The heads will come in 205cc and 185cc versions (stock intake runner volume is 173cc). And the combustion chamber size grows from 61cc to 65 cc.
As tested, Charlie quoted us the flow numbers that were up 7 percent at 0.300, up 14 percent at 0.400, up 17 percent at 0.500, and up 21 percent at 0.600. The heads will come assembled with Ferrera valves (2.02/1.60), ARP studs, rocker plates, and dual springs for cams of up to 0.600-inch lift. We've included our own measured flow numbers, which are right in line with what Trick Flow is claiming. The current trend in the 5.0 hobby is to build even more powerful 5.0 and 5.8 engine combinations than when the first Twisted Wedge head hit the market, and it looks as if these Trick Flow CNC-ported heads will fit right in.
As Charlie tells us regarding the goals of this project, "The customers we are after are the guys who may already have a set of Trick Flow heads and are looking to step up. They're looking to pick up 50-60 more without having to go through the hassle of sending their existing heads out to someone and not knowing what kind of work they'll get in return for their money. Of course, we also want the serious street 5.0 guys who will spend the money up front for a killer set of heads. It's going to be hard to improve on these things."
By the time you read this, Trick Flow will have CNC-ported Twisted Wedge heads on the shelf and ready for delivery, something it believes gives the company a leg up on the competition's lead times. The cost is $1,995, or around $800 more than the base castings. Considering what you get out-of-the-box without the hassle of involving a head porter, we think Trick Flow has made the decision easy for many small-block Ford engine builders. Also in the works are CNC-ported versions of the timeless Trick Flow Street Heat head due out by mid-summer. By SEMA and PRI, look for a killer set of CNC-ported Trick Flow Twisted Wedge R heads ready to bolt onto your favorite race car. It looks as if Trick Flow has stepped up its game, have you?
|Lift (inches) Intake (stock) Intake (CNC) Exhaust (stock) Exhaust (CNC)|
|0.100||63 (cfm)||66 (cfm)||53 (cfm)||54 (cfm)|
We were extremely interested in the flow numbers these heads would produce, since the base Twisted Wedge has been such a stellar performer for the last decade. This table shows the measured intake and exhaust flow numbers (at 28 inches of water pressure; exhaust tested with 4-inch by 131/44-inch pipe; intake port matched to Fel-Pro 1262R gasket; exhaust port matched to Fel-Pro 1415 gasket) from a Trick Flow Twisted Wedge CNC head courtesy of Paul Faessler of Paul's Automotive Engineering.
The numbers speak for themselves, but we will add that the increase is dramatic across the board. Paul even extended the test to 0.700-inch lift on the exhaust side with the CNC-ported version of the Trick Flow Twisted Wedge just to see if they have potential at that valve lift, and they certainly do. Impressive is the intake side where the stock castings start flowing at the 0.500-inch lift range-not surprising because that is where they work so well with the street camshafts for which they were designed. The ported version just starts breathing at 0.400-inch lift, and they continue to move the air well past 0.600-inch lift. This not only shows the potential of the CNC-ported head, but it also justifies this offering from Trick Flow with no questions asked.
On The Dyno
When we first got a look at our sample pair of Trick Flow Twisted Wedge CNC heads-the first ones let out of the factory-we were impressed. Compared side-by-side in our photographs, you can see the striking difference the port work provides. Visually, the heads are gorgeous, with all the port work featuring a super-nice finish from a smaller step-over process during the CNC porting. This costs more money for Trick Flow to do, but the end customer gets a beautiful set of heads and a better all-around product than the rougher-cut heads that you'll see on some of the competition.
We worked with Paul Faessler on this project. Paul has used Trick Flow products for years at his Paul's Automotive Engineering, and he's quick to compliment the company's professionalism and ability to deliver a top product at a good price. His SF-600 flow bench has always shown conservative numbers, but as you can tell from that accompanying table, the CNC-ported Twisted Wedges were quite impressive when compared to a stock casting. He also measured a 206cc intake runner volume, a 66cc exhaust runner volume, and a 65cc combustion chamber volume.
After the initial rounds of bench testing, we were curious as to how these babies were going to work in the real world. Luckily, Paul had just the car in his shop. Greg Brown's '86 coupe won the '04 American Iron championship with a 10.1:1 compression Paul's Automotive Engineering 347 small-block with the box-stock Trick Flow Twisted Wedge heads, a Victor Jr. intake, a Holley carburetor, and a custom camshaft of undisclosed dimensions. Even after a full season of fun, the car put down 375 hp to the wheels through a Tremec transmission. He was willing to let us give the CNC-ported Twisted Wedge heads a workout on his soon-to-be American Iron Extreme racer.
You power adder and big-inch Windsor guys should expect even a greater return on your investment than what we found.