Ford 4.6 Engine - Junkyard Jewel Ford 4.6l 2v -
Ford 4.6 Engine - Junkyard Jewel Ford 4.6l 2v - Engine Build Up
http://images.hotrod.com/techarticle...ord_engine.jpgFor several years HOT ROD has built what we call Junkyard Jewels: engines scrounged out of the junkyard and upgraded with bolt-ons in a step-by-step fashion in an effort to make good power on a realistic budget. We've covered most of the popular, traditional engines but haven't spent much time giving the Jewel treatment to late-model mills. This month we have two late-models: the 360 Magnum Mopar on page 96 and this one, an early 4.6L two-valve Ford mod motor.
We know some of you just cheered while others groaned. Modular Fords are polarizing engines even among Ford fans. Some love their smooth and high-winding overhead-cam ways, while others detest their lack of low-end torque and yearn for the familiar grunt and easy modification of the traditional Ford pushrod small-blocks. The following stratifies even further from there with five differing modular platforms to choose from: 2V, 3V, and 4V 4.6Ls, plus 2V and 4V 5.4Ls. Of them all, the pre-'99 2V engines are the red-headed stepchildren of the modular family, ignored by hot rodders and Mustang fans once they hit the salvage yard.
Of course that has a little something to do with the roots of the mod motors, which had little to do with performance. The 4.6L was the first of the Ford modular family and came on the scene in 1991 as the reliable and sedate powerplant for the Lincoln Town Car. From there it began to leach outward replacing the Windsor small-blocks and 385-series big-blocks in cars and trucks in response to impending emissions and mileage regulations. It was basically a case of using what was available and implementing it across the board for cost efficiency.
So what's the big issue with these early SOHC modular engines and why the bias against them? It's mostly in the heads and their restrictive design. While '99-and-later 4.6 2V engines benefited from the Performance Improved, or PI, heads and intake that boosted Mustang horsepower to 260-plus and put torque around 300 lb-ft, the early ones had miserable flow characteristics and around 215 hp on a good day. That coupled with extra labor involved in modifying them due to the complexity of the engine design, plus limited aftermarket support even after 13 years of production, has kept most hot rodders at bay. That's too bad, because with roughly 5 million produced, there are a lot of cheap used ones available.
But that's also the good news. Since the 4.6 two-valve was the fleet engine of choice for taxicabs and police cars as well as hundreds of thousands of Crown Vics, trucks, vans, and Mustangs, they're usually easy to find and cheap to buy. Our little cammer was pried from a T-boned '97 Crown Victoria for the reasonable sum of a $400, with 117K on the odometer and the usual assurance from the seller that it was a well-taken-care-of and kindly driven old man car.
The methodology for this test will be a little different from our usual format because we have to a do a little parts swapping right off the bat just to do our initial testing. Though it looks mostly complete, our 4.6 is missing the Crown Vic's computer and has some mangled harness wiring, so it would necessitate a lot of unnecessary time and expense to run in its fuelie form. But we're not interested in EFI numbers for this mod motor, since we were able to get our hands on Edelbrock's brand-new Victor Jr. carb intake that comes with MSD's 6 Mod ignition controller. Since goal number one is to remove all that junk anyway, we're going to give the 4.6 the benefit of the doubt and assume the original 210 hp and 270 lb-ft numbers are reasonably on par and start stripping it down to the bare essentials.
Stage 1
Since we're old-schooling this mod motor with a carburetor, the first step in the build is a doozy. After ripping off the fuel injection, the first obvious piece we need to install is the Edelbrock intake with the accompanying MSD ignition mod. The problem is that it's not directly compatible with our early non-PI heads, so we can't simply bolt it on. The biggest difference between the PI and non-PI heads is the shape of the port. We could spend time reshaping them to match, but the more sensible solution is to bolt on a set of PI heads from a '99-and-later 4.6, since they're cheap and readily available. Plus, swapping the PI heads onto our earlier non-PI engine also gives us the benefit of a big bump in static compression due to the difference in the combustion-chamber volume on the PI heads. The '96-'98 non-PI heads have a 49.77cc combustion chamber and pistons with a 153cc dish, while '99-'04 PI heads have a 42.45cc combustion chamber and a deeper 188cc dish. When we use PI heads with stock head gaskets on a non-PI short-block, we end up with a compression ratio in the neighborhood of 10.5:1.
Our PI heads and cams are used parts from a Mustang GT and received nothing more than a basic cleanup and inspection at Ford Performance Solutions (FPS) in Anaheim, California, to ensure they were in good working order. These are regularly available in junkyards and on eBay for around $150 to $400, depending on mileage. The long timing chains and guides looked to be in great shape when we pulled the front cover, so we reused everything with the PI heads. The later 4.6 heads use 14-bolt valve covers rather than the 11-bolt ones our early engine had, so we purchased a set on eBay.
Though the MSD 6 Mod ignition controller looks complicated when you first pull it out of the box, it practically lays itself out when placed on the engine. The harness comes preterminated with clips for the coils and the cam, crank, and MAP sensors so only ground and 12V ignition signals are required.
For our first run, we used the stock timing table that comes preloaded in the MSD 6 Mod controller to establish a baseline. Performance numbers were up considerably from the stock rating, but we were seeing a lean condition and timing was only 19 degrees total.
DYNO RESULTS: STAGE 1 RPM LB-FT HP 3,000 254.9 145.6 3,200 260.8 158.9 3,400 282.9 183.1 3,600 270.4 185.4 3,800 270.9 196 4,000 273.7 208.5 4,200 273.3 218.5 4,400 271.1 227.2 4,600 270.8 237.2 4,800 269.5 246.3 5,000 267.3 254.5 5,200 261.7 259.1 5,400 264.6 272.1 5,600 267.9 285.7 5,800 261.4 288.7
PRODUCT Price 1 ’97 4.6L Crown Vic engine with 117K $400.00 1 Edelbrock Victor Jr. carb intake manifold with MSD 6011 ignition module $759.95 1 pair 4.6 PI Mustang heads and cams with unknown mileage $250.00 1 pair PI valve covers $15.00 1 Used Holley 650-cfm double-pumper $150.00 8 Autolite 764 spark plugs $12.72 1 oil filter $3.99 5 quarts oil $17.00 8 stock ’99-and-later Ford ignition coils $75.00 1 BBK equal-length shorty header set $299.99 1 Fel-Pro valve-cover gasket set for PI 4.6 $36.99 1 Fel-Pro head gasket kit $48.99 1 Fel-Pro 4.6 PI intake gasket set $43.99 1 Fel-Pro 4.6 PI exhaust gasket set $11.99 1 set 4.6 head bolts $69.00 1 11/2-inch expandable freeze plug $2.99 1 5/8-inch hose cap and clamp $1.99 Stage 1 Total $2,199.59 HP: 288.7LB-FT: 273.9
We could have tracked down some stock 4.6 manifolds but opted to upgrade to BBK headers since the log-style stockers will only hold us back as we progress. Long tubes won't clear the dyno so we chose BBK's equal-length shorties for the testing.>
Stage 2We knew there was more in this combo, so we spent a little time getting familiar with msd's ignition program. since our mod motor is carbureted, we're only dealing with the timing curve and advance, which still takes some trial and error-especially since we had no prior testing to extrapolate from. the 6 mod is user-friendly enough for amateurs, plus there are some built-in fail-safes to help ensure against engine damage. we created a basic timing curve that gave us 32 degrees of total timing by 3,000 rpm. our air/fuel ratio was getting dangerously lean on the top end of the dyno run, so we went up four sizes on our secondary jets from 73 to 77 but left the 67s in the primary. this run backed up our theory that it was all in the tune and that our junkyard long-block had a lot more to offer, as we saw power go up across the board from simple changes.
PRODUCT PRICE 1 pair of jets for Holley carb $5.00 Adjust timing STAGE 2 TOTAL: $5.00 HP: 313.6 LB-FT: 315.1 Gain: +25.1 hp and +41.8 lb-ft
DYNO RESULTS: STAGE 2 RPM LB-FT HP 3,000 283.2 161.8 3,200 295.3 179.9 3,400 301.8 195.4 3,600 309.7 212.3 3,800 311.9 225.7 4,000 315.6 240.4 4,200 310.2 248.1 4,400 313.1 259.5 4,600 314.9 275.8 4,800 315.1 288.0 5,000 311.9 297.0 5,200 306.5 303.4 5,400 300.2 308.7 5,600 293.1 312.5 5,800 284.0 313.6 6,000 259.1 296.0
Stage 3
After a few consecutive runs with little to no change despite a guesstimation on the timing curve, it was time for the next evolution of our 4.6. These heads are complex and require exacting precision to manufacture since the cam rides directly on the surface of the head, but it's still amazing that no one has produced an aftermarket cylinder head for the 4.6. The solution is to thoroughly CNC-port the factory heads to try and eliminate the faux pas that choke performance. Ford Performance Solutions performed its CNC work on the heads then hit 'em with a small amount of hand-porting. We also opted to upsize our valves from the factory 44.5 mm and 36 mm to 45.2 mm and 36.8 mm at SI Valves in Simi Valley, California. For now we'll keep the stock PI cams so we can see what the heads alone offer. The headwork paid off big time as we saw both power and torque increase dramatically with no other changes.
PRODUCT PRICE 1 pair CNC-ported 4.6 PI heads with 46mm SI valves $1,199.99 STAGE 3 TOTAL: $1,199.99 HP: 346.1 LB-FT: 341.2 Gain: +32.4 hp and +25.5 lb-ft
HEAD FLOW CHART INTAKE BEFORE AFTER 0.100 54 57 0.200 102 109 0.300 139 157 0.400 159 180 0.500 169 204 0.600 175 215 0.700 176 226
EXHAUST BEFORE AFTER 0.100 55 57 0.200 91 98 0.300 121 136 0.400 137 172 0.500 142 187 0.600 150 194 0.700 153 209
DYNO RESULTS: STAGE 3 RPM LB-FT HP 3,000 292.8 167.3 3,200 305.4 186.1 3,400 315.7 204.4 3,600 322 220.7 3,800 327.7 237.1 4,000 331.9 252.8 4,200 334.7 267.6 4,400 337.5 282.8 4,600 340.4 298.1 4,800 341.2 311.8 5,000 339.1 322.8 5,200 335.2 331.9 5,400 329.7 339 5,600 321.7 343 5,800 313.4 346.1 6,000 302.8 345.9
Stage 4
With fuel consumption showing that the 4.6 still didn't want a larger carb and timing adjustments not resulting in any power gains, our next logical move was to swap the stock cams for something a little more aggressive. Of course, all off-the-shelf mod motor cams are ground with fuel injection in mind, so we took an educated guess as to what the engine would want. We selected Comp Cams XE274H grind originally intended for the earlier non-PI heads with a 114-degree lobe-separation angle. Though they aren't overly aggressive, the cams would easily overwhelm the factory springs, so we also went with Comp's standard mod motor springs to keep things stable. On the first and only run we were able to make, we saw power drop off quite a bit on the bottom end, with the PI cams besting the Comp parts until 4,800 rpm, where the Comp cams started to come alive. We were quite sure we could recover a significant amount of the power loss with some adjustment of the timing curve and we knew there was more power to be had at 6,500 rpm, but sadly it wasn't meant to be.
PRODUCT PRICE 1 pair Comp Cams XE274H $496.19 1 set Comp Cams valvesprings P/N 26113-16 $166.87 1 set Comp Cams steel retainers P/N 792-16 $50.40 STAGE 4 TOTAL: $713.46 HP: 370.4 LB-FT: 345.4 Gain: +24.2 hp and + 4.6 lb-ft
STAGE 1 $2,199.59 STAGE 2 $5.00 STAGE 3 $1,199.99 STAGE 4 $713.46 TOTAL: $4,118.04
DYNO RESULTS: STAGE 4 RPM LB-FT HP 3,000 277.7 158.6 3,200 281.7 171.7 3,400 287.8 186.3 3,600 293.9 201.5 3,800 303.0 219.2 4,000 314.2 239.3 4,200 324.7 259.7 4,400 333.1 279.0 4,600 338.9 296.8 4,800 342.7 313.2 5,000 345.3 328.7 5,200 345.4 342.0 5,400 341.3 350.9 5,600 335.5 357.7 5,800 330.0 364.4 6,000 324.2 370.4
What's Next?
Sometimes time limitations sneak up on us, and that was the case here. We were putting this engine together during the hectic holiday season and didn't get as much dyno time as we'd like nor did we get to wring out as much power as we wanted from this Jewel. Finding an extra 160 hp on a junkyard 2V 4.6 is fairly respectable, but we're quite sure there's more in it, so watch for an update in a later issue. Ford Performance Solutions would like to see what a thorough porting of the intake would yield, and our ignition tune could likely use some more tweaking. After dialing it in and spinning it to at least 6,500 rpm, 400 hp should be within reach. At that point, we'd be pretty near the reliable limit of the factory internals, especially considering our thin early rods and stock, fragile oil pump gears, which tend to shatter like glass when overstressed. In the meantime, we're suddenly seeing a lot more low-buck potential for fun in early 4.6 Mustangs, and maybe even some Crown Vics and T-birds.
Photo Gallery: Ford 4.6 Engine - Junkyard Jewel Ford 4.6l 2v - Engine Build Up - Hot Rod Magazine
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