Budget Mod Motor Build - Car Craft Magazine

What were you doing in 1991? The Gulf War was waged, Rodney King got a beat down, the Pittsburgh Penguins won their first Stanley Cup, the Minnesota Twins won the World Series, and Ford Motor Co. dropped the first 4.6L single overhead cam, two-valve-per-cylinder modular V-8 engine into a Lincoln Town Car, thus beginning its phasing out of the pushrod V-8.

The early mod motor was almost universally panned. As it rolled out across the other FoMoCo car lines, the critics became louder and more numerous. The most vociferous among them were Mustang owners, who largely despised the engine. The '96 Mustang, the first to boast mod motor power, carried the same 215hp rating as the previous year's car, the last with the venerable Five-Oh engine, but you wouldn't know by driving it. The power delivery was differ-ent from that of the outgoing pushrod engine, it had less low-end grunt, and it needed to rev higher to reach its powerband. As the Europeans are quick to point out, this situation is intolerable to Americans who demand the instant torque needed to win stoplight drag race wars. Mod motor Mustangs were getting their asses handed to them at intersections all across the country by smug Camaro and Firebird owners who had 275 hp from 350ci LT1s.

Ford responded by rolling out versions with more horsepower, but the company was a little too slow in doing so, and the unfortunate gutless, complicated, expensive stigma surrounding this engine remains in some segments to this day. One could argue that Ford may have prevented this by introducing the 280hp four-valve version first and putting it straight into the Mustang. Such was not the case, though, and the engine has struggled to gain the hearts of the masses. Compounding the problem, the aftermarket was slow to embrace the modular V-8, and that has kept many enthusiasts from building these engines. With the introduction of Trick Flow's two-valve heads, we think the tide is changing and that we'll be seeing more of the mod motor in performance applications.

This article is an overview of the performance potential of the mod motor. We received expert advice from the guys at Modular Mustang Racing (MMR) and Modular Head Shop. They gave us a few build options to consider and warned us of some traps to avoid along the way. This engine is a worthy platform and is capable of making an impressive amount of power. Let's investigate.

Engine Blocks

Modular blocks are cast in either aluminum or iron at either the Windsor, Ontario, or Romeo, Michigan, plant. There are a few differences between the Windsor and Romeo blocks, but the cylinder heads all interchange. Look for a W cast into the boss near the starter to know if your engine came from Canada or not. Regardless of the material used, any modular block is good to at least 800 hp. That means the block in the taxi rotting in the corner of the junkyard has just as much performance potential as the block in the '03 SVT Cobra, the so-called Terminator engine. The blocks use a deep skirt design with cross-bolted main bearing caps. From the factory, they are a lot stronger than a 5.0L block. They have a reputation for longevity, too. Our sources have seen modular engines with 500,000 miles that still meet the factory specs. All 4.6 blocks can use any 4.6 crankshaft and rod bearings, but the Windsor and Romeo blocks use different main caps and bearings.
Modular blocks are cast in either aluminum or iron at either the Windsor, Ontario, or Rome
The two blocks also have different reinforcement ribbing in the lifter valley. Unlike the Windsor style shown here, Romeo blocks have smaller ribs running across the valley from side to side.
The two blocks also have different reinforcement ribbing in the lifter valley. Unlike the
The 5.4 blocks are immediately recognizable by their taller decks. The machined pad above the core plug shows the extra material. The deck on 4.6 blocks is nearly even with the top of this core plug.
The 5.4 blocks are immediately recognizable by their taller decks. The machined pad above

Aluminum blocks are desirable for their weight-saving advantage over the iron blocks. Of the aluminum blocks, the earlier ones cast in Teksid, Italy, are reported to be the best available, aside from the mid-engine, dry-sump Ford GT block. This is a customer's Teksid block being assembled at MMR. It is recognizable by fewer ribs in the valley than in the later Windsor aluminum blocks.
Aluminum blocks are desirable for their weight-saving advantage over the iron blocks. Of t
The Teksid blocks were used in all 4V 4.6 engines from '93 to '98. We've seen several in the junkyards and even more selling for cheap on eBay. Make a beeline for the nearest Lincoln MK VIII, pull the engine, and get ready to make 1,000 hp. These blocks were also in '96 to '98 Mustang Cobras.
The Teksid blocks were used in all 4V 4.6 engines from '93 to '98. We've seen several in t

Specs
	4.6L Engines	5.4L Engines
Cubic inches	281	330
Bore	3.552	3.552
Stroke	3.543	4.165
Bore spacing	3.937	3.937
Deck height	8.937	10.078
Main journal diameter	2.657	2.657
Rod length	5.933	6.658
Bare block weight, iron	154 pounds
Bare block weight, aluminum	86 pounds

Note that the bore and bore spacing are the same for the 4.6 and 5.4. Therefore, any cylinder head will fit on any block. You do need to check the head gaskets, though. The oil holes may be in different locations and could cause oil to leak into the coolant. Your best bet is to use Ford Racing's head gaskets.

Performance 2V Build No. 1
We talked with Modular Head Shop's Nick McKinney at length about his recommendations for a performance build. He told us nearly 60 percent of his customers are early Mustang, Crown Vic, Thunderbird, and Cougar owners. Since these are predominately two-valve cars, he's something of a 2V specialist and has several combinations he recommends to suit his customers' budgets. On his website, McKinney lists a parts combination that will make at least 300 hp at the wheels. Best of all, it costs less than $2,500, including new gaskets, timing chain tensioners, and sprockets. It's basically a cam, head, and intake swap, so you can reuse your bottom end. Assuming everything is in good shape, the stock reciprocating assembly will easily handle the increased power. We'll highlight some of the parts here.

To review, the 2V engines got a makeover in 1999 when Ford, responding to customers' pleas for more power, redesigned the cylinder heads. These Power Improvement (PI) heads had smaller combustion chambers combined with bigger intake runners. Matching the heads was a new, better-flowing intake manifold. The increase in flow and more efficient combustion was worth more than 30 additional horsepower over the non-PI (NPI) design.
To review, the 2V engines got a makeover in 1999 when Ford, responding to customers' pleas
McKinney says the 2V engines have the potential to be great performers, "They just need more compression and better cams. These engines love compression." He recommends at least 10.4:1, and it turns out the hot ticket is to start with an NPI block. To accommodate the smaller combustion chambers of the PI heads, Ford equipped the '99-and-later engines with dished pistons that put the compression ratio at 9.4:1. Dropping PI heads on an NPI block will yield his recommended 10.4:1 compression ratio.
McKinney says the 2V engines have the potential to be great performers, "They just need mo
The 300hp formula calls for McKinney's Stage 2 ported PI heads, which he sells complete and ready to install for $1,195. They include stainless steel valves that are slightly larger than stock, bronze guides instead of the stock powdered metal ones, Pacaloy springs, and a performance valve job. This is a good deal considering that a pair of new PI heads from Ford cost about $900.
The 300hp formula calls for McKinney's Stage 2 ported PI heads, which he sells complete an

You'll also need bigger cams to break the 300hp barrier. McKinney said he spent lots of time working with Mark Chacon at Bullet Racing Cams to design profiles for the 2V engines. He recommends his Stage 2.5 NA cams that spec out at 228/226 degrees duration and 0.550/0.500 lift on a 108-degree lobe-separation angle. Unfortunately, McKinney doubted if those cams would pass a tailpipe emissions test. So McKinney recommended his Stage 2 Turbo cam: 222/218 duration, 0.525/0.500 lift, 115-degree LSA, and said it would probably make 5 to 10 fewer horsepower at the wheels. McKinney said he prefers the smaller exhaust lobes with the PI heads because the exhaust port flows very well.
You'll also need bigger cams to break the 300hp barrier. McKinney said he spent lots of ti
Piston-to-valve clearance is something to be concerned about with the 2V engines. The redesigned combustion chamber puts the valves right at the deck of the engine block. That, plus the funny-shaped ridge around the perimeter of the intake valve cause very close piston-to-valve clearance numbers.
Piston-to-valve clearance is something to be concerned about with the 2V engines. The rede

You will bend your intake valves for sure if you run an aggressive camshaft. McKinney told us proper cam timing is critical. He recommended maintaining a 0.035-inch piston-to-valve clearance, and it is easy to exceed this spec. For example, installing a popular street cam with 225 degrees duration at a 112-degree intake centerline will give you 0.070 inch of clearance. Advancing that same cam 2 degrees to 110 will give you 0.035 inch of clearance. Advance it 2 more degrees to 108, and you will only have 0.005 inch of clearance. The problem is that these engines like more intake valve timing, and a popular option is to have the pistons notched for intake valve clearance. You can send McKinney your pistons and he'll notch them for $129. It's also a good idea to replace the intake valves with aftermarket ones without the perimeter ring. McKinney also stressed that the cam timing should always be checked. He said the factory timing sprockets are notoriously inaccurate and can be off by as much as 4 degrees either advanced or retarded. Degree your cams when assembling the engine. If the timing is off, you'll need to buy a set of zeroed or adjustable gears. Rounding out the 300hp combo, you can reuse your factory PI intake and add both a JLT intake with a 90mm mass airflow sensor and a performance exhaust system with a pair of long-tube headers: simple, cheap, and effective. If you still have some extra money to spend, McKinney recommends building all this on top of an aluminum 4V block out of a Mark VIII. In stock configuration, these were 10.0:1 engines. With PI heads, your compression ratio will be almost 12.0:1. That plus the nearly 80-pound weight advantage of the aluminum block will give you even better performance at the track. Whether you use the aluminum block or not, with this combination you'll be making more power at the wheels than the Camaro and Mustang guys are making at the crank.

Power Improved By The Numbers
Engine	Piston Dish	Combustion Chamber Size	Compression Ratio
NPI	11 cc	51 cc	9.30:1
PI	17 cc	42cc	9.74:1
Ideal*	11 cc	42 cc	10.4:1
*Using a stock head gasket with 0.036-inch compressed thickness with -0.015-inch piston-to-deck height

Cam Specs
NPI	201/208 duration at 0.050, 0.462/0.462 lift, 114/113 intake/exhaust centerline
PI	200/209 duration at 0.050, 0.505/0.531 lift, 116/116 intake/exhaust centerline

Valvetrain
Valve size	1.752/1.339-inch
Cam follower	Roller type with 1.80:1 ratio

Performance 2V Build No. 2
MMR's TWO-Valve Street Thrasher Modular Mustang Racing is about two hours away from our offices, so we spent several hours poking around its shop for some more build ideas. Engine builder Alex Clochiatti outlined a cool build for us, which is a variant of the Street Mod 600 long-block the company sells as a crate engine on its website. This build starts with a new 4.6 block, a cast crank with forged rods and pistons, new PI heads, degreed PI cams, and ARP fasteners. This combination sells for $4,499.

Clochiatti's Street Thrasher recommendation swaps out the PI heads in the Street Mod long-block for a set of Trick Flow's new 2V cylinder heads. We ran a press release when TFS first released these things last year, but this was the first time we got to compare them with Ford's PI heads side by side. Note the different shape of the Trick Flow combustion chamber (left).
Clochiatti's Street Thrasher recommendation swaps out the PI heads in the Street Mod long-
When redesigning the heads, Trick Flow relocated the intake valves, arranging them in a way reminiscent of the original SOHC Cammer engine of the '60s The intake valve is the bottom one in the picture. The exhaust valve is in the stock location and angle.
When redesigning the heads, Trick Flow relocated the intake valves, arranging them in a wa
The new intake valve angle of the Trick Flow heads eliminates the piston-to-valve interference problems, now allowing guys to run cams with valve lift to 0.600 inch. It also improves airflow from the intake manifold to the valve. You can buy these heads from Summit Racing for $997.95 each, and Clochiatti and Modular Head Shop's McKinney both say that out of the box, the Trick Flow heads outflow any safely ported factory 2V heads. If there is a downside to all this extra airflow, it's that most naturally aspirated street engines may not be able to take advantage of it. The Trick Flow heads may be better suited to forced induction or stroker builds.
The new intake valve angle of the Trick Flow heads eliminates the piston-to-valve interfer

The other key element to the Street Thrasher combo is a stroker package. Dropping in a 3.75-inch stroke crank will get you the magical 5.0 liters, and MMR's stroker package includes a forged crank, forged H-beam rods, and forged pistons in the compression you choose. The assembly also includes bearings and has been balanced prior to shipping. Clochiatti said this bottom end will support up to 850 hp. In this photo are some of the piston and rod combinations for stock and long-stroke builds. So far everything we've mentioned for the 4.6 will also work for a 5.4 engine except the stroker package. Clochiatti said MMR does not recommend building a 5.4 stroker engine because the geometry creates too great a side load on the cylinders. If you want to add displacement to a 5.4 block, you're going to have to sleeve it.
The other key element to the Street Thrasher combo is a stroker package. Dropping in a 3.7
For the ultimate naturally aspirated 2V Street Thrasher, build the stroker motor using Ford Racing's Boss 5.0 block. Part number M-6010-BOSS50 is a cast-iron Windsor block with a 3.75-inch bore. With the stock 4.6 crank, it makes a 5L engine. Add the stroker package, though, and you've got an LS-killing 5.3 mod motor. You'll be getting up there in price, however, and our rough calculations put this combination at just north of $7,500. For that money, you could have had 32 valves instead of 16.
For the ultimate naturally aspirated 2V Street Thrasher, build the stroker motor using For

The MMR 4V build
MMR's Rick Antonette told us that building a four-valve engine out of a two-valve engine is really no big deal. "Any cylinder head will go on any block. You just need to match the rest of the components to the block and head combination you choose." This is because some of the cam gears, chain tensioners, and timing covers are different from engine to engine. So pick your short-block (MMR recommends a stroker if you're building a 4.6) and add a set of heads.

The DOHC and SOHC engines use the same main timing chain. The secondary cams are driven by a smaller chain off the exhaust cam sprocket.
The DOHC and SOHC engines use the same main timing chain. The secondary cams are driven by
The best 4V cylinder heads are on the '00 Cobra R and Ford GT, but don't expect to find those cheap. The Mark VIII heads are good, though. They are known as the B heads, and you will be able to find lots of them for not a lot of cash. Incidentally, you can see why a four-valve-per-cylinder arrangement will always move more air than two valves. There's much more valve area. Antonette tells us about the best you can get out of a 2V engine is 500 hp, and you'll need forced induction to make that. Customers who want more than 500 hp are steered toward building 4V engines.
The best 4V cylinder heads are on the '00 Cobra R and Ford GT, but don't expect to find th
The B heads ('93 to '96 MK VIII and '96 to '98 Mustang Cobra) had unique intake manifolds with a split-runner system. Called the IMRC (intake manifold runner control), the engine breathed just through the squared-off ports under light-load conditions. At heavy loads or full-throttle, butterfly valves in the intake runners would open up the circular ports, too. On paper it works well, but in reality, the butterfly valves would get stuck over time and not open fully. MMR sells an adapter plate that eliminates the IMRC, allowing you to take full advantage of the B head's potential.
The B heads ('93 to '96 MK VIII and '96 to '98 Mustang Cobra) had unique intake manifolds

You can also opt for MMR's new sheetmetal intake. It weighs less than half the Cobra intake to the right of it, has better flow, and deletes the IMRC. The throttle body mounts in the stock location, and it fits under the hood without any modifications.
You can also opt for MMR's new sheetmetal intake. It weighs less than half the Cobra intak
The biggest problem with a 4V build is that the cost adds up much more quickly than with a 2V engine. "There are twice as many cams, twice as many valves, springs, seals, retainers-it gets expensive pretty quickly," Antonette says. Still, if huge power is what you're after, you need the extra valves. Five hundred horsepower is easily achievable with a 4V engine, and racers are making well over 1,000 with a power-adder and a forged bottom end inside a stock block.
The biggest problem with a 4V build is that the cost adds up much more quickly than with a

Build It
We hope this article has given you a better look at the potential lurking within the relatively tiny 281 ci of Ford's modular V-8. We only scratched the surface, though, so we recommend readers hungry for more mod motor information read How To Build Max Performance 4.6-Liter Ford Engines by Sean Hyland and Building 4.6/5.4L Ford Horsepower on the Dyno by Richard Holdener. Both books are published by SA Design and provide a lot of excellent information that we couldn't fit in the space allotted this month. Also, go online to modularfords.com and search the forums. There's a lot of good info there, too.

Just because we are fans of this engine doesn't mean anything if our readers don't care. What do you think? Are we out of our OHC minds? Do you want to see a build? Or will you cancel your subscription if the words mod and motor appear next to each other again? Let us know at CarCraft.com.

SOURCES
Trick Flow Specialties 1248 Southeast Avenue Tallmadge OH 44278 330-630-1555 www.trickflow.com	Bullet Cams 8785 Old Craft Road Olive Branch MS 38654 662-893-5670 www.bulletcams.com
Ford Racing Performance Parts 15021 Commerce Drive S Suite 200 Dearborn MI 48120 800-FOR-D788 www.fordracingparts.com	Modular Head Shop Cassleberry FL 321-262-1132 www.modularheadshop.com
Motorbooks International 729 Prospect Ave P.O. Box 1 Osceola WI 54020 715-294-3345 www.motorbooks.com	Modular Mustang Racing Ventura CA 805-650-1853 www.modularmustangracing.com
CarTech Books 39966 Grand Avenue North Branch MN 55056 651-277-1200 www.cartechbooks.com