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By Chirag Asaravala

Is the 2V Worthy?
When Ford debuted the 260 HP 4.6L 2V in the '99 Mustang GT it was the highest horsepower levels ever offered in the pony car since Detroit began reporting real engine horsepower. Yet the terrible power to weight ratio due to the 600 extra pounds carried by the new body style left enthusiasts longing for the 5.0L glory era of EFI Fords. Achieving 300 horsepower to the wheels with a 5.0L has been a simple matter of bolting on one of many cookie-cutter combinations of aftermarket heads, cam, and intake manifold. After all the 5.0L crowd benefited from decades of preexisting aftermarket product development for Ford's small block

The motor in this article will go into Project 01 'cus we spun a rod bearing in the stock motor last month.

pushrod engine family. The overhead cam guys had no such lineage. What limited speed parts that were available for mod motors were expensive and included a degree of difficulty beyond the capabilities of most garage enthusiasts.

Fortunately things have changed over the past several years. Thanks to a host of aftermarket companies and engine builders dedicated to climbing the steep learning curve of the mod motor, that crowd now has its own set of high-power recipes. Companies such as Comp Cams have developed a nice lineup of overhead cams and upgraded springs. And while we don't yet have a true aftermarket modular cylinder head we have several companies offering CNC ported versions of the stock castings. Other products are quickly emerging too; a couple companies are finishing development of an aftermarket intake manifold. Fidanza Engineering has produced adjustable cam gears which open up the realm of degreeing and dialing in the powerband.

So the question that has to be asked is whether or not the 4.6L 2V, despite it's 21 fewer cubes, is now capable of achieving the 300-plus rear-wheel power levels from bolt-on modifications? Moreover, can the average 400-piece Craftsman tool set owning weekend enthusiast overcome the mod-motor modification fears and perform a head an cam swap himself? We think so. In this article we've teamed up with HCI Motorsports to show you how to install a set of Patriot Heads and Comp Cams in your 2V motor. In the next issue we'll drop the motor in our 2001 Mustang GT and reveal the dyno results.

CNC Ported Cylinder Heads
If you want to improve upon the flow of the PI heads you have to port the stockers. (PI means "Power-Improved" referring to the revised casting introduced by Ford in 1999. The PI heads are a significant improvement over the '96-'98 castings.) While hand porting is possible for the highly-skilled, it is undoubted more cost effective to purchase a set of CNC ported PI heads from Patriot Performance. They offer three stages of their 5-axis CNC porting program. Patriot's Gunnar Bowlin tells us, "We no longer mention the Stage 1 as it is priced so close to the Stage II and on any level motor the Stage II is a good fit." The Stage III head is only recommended when the bore is oversized at least 0.020" as the larger valve will otherwise be shrouded. Of course the Stage III also means high-rpm power band and/or power adder is a prerequisite. Patriot's heads feature larger valves, new springs and best of all do not require sending in a core. The Stage II's sell for $1295 outright and that is what we selected.
.

The intake port on the Patriot stage II head measured 1.700" wide by 2.050" tall (we measured at the center horizontal and vertical axis' of the port. Note that the port is opened up to the stock gasket dimensions. On the Stage III head the increased flow is a result of a larger valve and hand blending in the bowl area.

The stock intake port on our PI (performance improved) head measured 1.510" wide by 1.870" tall, significantly smaller than the intake gasket.

The Patriot Stage II heads feature exhaust ports opened up .080" over stock to 1.420" diameter. The result is a 30% improvement in flow.

The stock exhaust port diameter is 1.350".

Patriot upgrades the valves to 1.78" x 1.45" (45.2mm x 36.8mm). The swirl dams in the combustion chamber are ground down and the chamber is polished. This brings the chamber volume up slightly to 46cc from 42cc stock. This will reduce compression ratio by less than half a point.

The stock valve sizes are 1.75" x 1.42" (44.5mm x 36mm). The cupped valves make up for the volume consumed by the swirl dam above the intake valve and the raised pad between the two valves adjacent the spark plug hole. Both are factory attempts to promote combustion mixture and reduce emissions. The swirl dam however shrouds the intake valve significantly and is removed by Patriot and other CNC porting companies.


4.6L 2V PI Cylinder Head Flow Data
Patriot Performance Stage II vs. Stock
 
 
CFM (28" H20)*
 
Stock
Patriot
Lift" Int Exh Int Exh
.100 53 49 63 57
.200 105 84 114 100
.300 140 107 160 132
.400 155 123 189 158
.500 159 133 211 177
.550 162 135 216 181
.600 164 138 220 185
*Flowed with 3.55" diameter bore fixture.

(Installing Patriot heads and Comp Cams)
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In This Article:
When it comes to Ford's "modular" motors the 4.6L 2V is often quickly dismissed for it's four-valve cousin by those in search of serious power. However there are many who have embraced the two-valve motor and have found ways to squeeze respectable power out of it. We spent the day with HCI Motorsports as they transformed the 2V in our Project 2001 Mustang.

   
 
We selected the Comp Cams XE262AH (PN:102500) cams and matching beehive springs (PN:26113-16) for our project. The cams are the smallest of the three Xtreme Energy cams offered with 226/230 duration and .550" lift. They won't require a computer re-tune, will idle fine, and are known to pass CA emissions testing, hence the reason we selected them. More on the other Comp Cams on page 2.
   
 
We've bugged companies like AFR to make a true aftermarket 2V head, but it may never happen due to the relatively low demand and super tight tolerances needed due to the cams. The next best thing is Patriot Performance's CNC ported cylinder heads. Shown is their Stage II (see left for details and flow specs.) This is a Romeo Engine Plant (REP) cylinder head (evident by the bridged cam caps or cam "girdles".) The Windsor Engine Plant (WEP) 4.6L engines use individual bearing caps. Patriot can supply either head.
   
 


Fidanza Engineering has developed adjustable cam gears (PN:986836 & 986736) for the 2V motor. The cam gears will allow for up to 12 degrees retard or advance. This enables dialing in the cams relative to crank position, something not possible with the stock gears (left.) These gears also also a good option if you are putting cams in a WEP motor because they had gears which pressed on to the cams and therefore wont work with aftermarket cams.

 
Recommended References
$12.32
How to Build and Modify 4.6-Liter Engines” by Sean Hyland gives you a comprehensive guide to building and modifying Ford's 2- and 4-valve 4.6/5.4-liter engines. You will learn everything from block selection and crankshaft prep, to cylinder head and intake manifold modifications. He also outlines eight recommended power packages and provides you with a step-by-step buildup of a naturally-aspirated, 405-horsepower Cobra engine. 128 pgs, 320 black & white photos and illustrations.

 Only $12.32


"High-performance Mustang Builder's Guide 1994-2004"
by Sean Hyland, 144 pages.

 Only $15.72

 


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