Big-Block Ford Engine Build: Easy 500 HP From the Ford 460
Did you know that Ford built the same big-block for 30 years? They're everywhere, making them a simple score for an easy 500 hp from the Ford 460.
What is it about American iron that is all about massive? Chrysler's original Street Hemi had valve covers that you could rent out as a dance floor. Pontiac's V-8 is a hefty chunk of iron, and so are the Olds 455s. But if you want to talk cast-iron overkill, perhaps we should speak of the Ford 429/460. Massive 3-inch main bearings and hefty iron heads combined at one time in the smog era to put out a measly 206 hp. Thank god those days are over.
But in classic car crafter tradition, we see not those inept days past and look instead to the massive amount of power we could create out of all that iron. Here perhaps is one of the domestic world's overlooked power gold mines. Yes, it's heavy, and yes, it costs more to build than a small-block Chevy—but then you already knew that. Think of this as a line drawn in the sand. Are you man enough?
We decided to do more than talk about Ford's big-block and actually build one ourselves. Well, actually Jim Grubbs Motorsports built it for us because we're inept at time management. The crew at JGM are true Ford 460 fans, and so we found an enthusiastic partner to point us down the proper path to Blue Oval power. Think of this as looking at the horsepower world through Ford blue-tinted glasses. Very heavy glasses.
What's Out There
The Lima series engine is one of Ford's most enduring powerplants. Arriving on the scene in 1968 first as the 460 in Lincolns and as the 429 in other big Fords, this 385-series engine survived until 1997, a 30-year run that is astounding given Ford's proclivity for change. Used in tugboat Lincolns through 1978 and later in fullsize Fords and Mercurys, the 460 also torqued its way into 31/44-ton trucks and E-350 vans from the '70s all the way through the early '90s. This veteran engine can also be found in motor home, marine, and even stationary industrial applications and has been electronically fuel injected since 1987.
The going price for complete motors varies by condition, but we've heard they go for as little as $200. We bought ours for a bit more from Memory Lane mainly as a complete engine including all the accessories because we were in a hurry and couldn't take the time to look for a less expensive version. Adopt one and take it home. The Ford gods will smile on you.
Bores and Strokes
The 460 and its 429 cousin are big-bore, short-stroke thumpers. The 460 employs a 3.85-inch stroke, while the 429 uses a mere 3.59-inch reach. This makes increasing displacement on the 429 easy enough. The rod length is 6.605 inches, which makes for a 1.71:1 rod-length-to-stroke ratio with the stock 460 stroke. Most production blocks can tolerate overbores to 0.060 inch, creating a 472. If you're willing to search for a thick-wall casting, it's possible to go to 0.080-over (4.440-inch bore) and 477ci with the stock stroke.
If massive inches are your plan, there are several stroker crank options. You can offset-grind the stock 2.500-inch rod journals down to 2.200 big-block Chevy or Chrysler pin size. Or plug in any one of three Scat cast stroker cranks. At 0.030-over, the 4.150-inch stroke makes 502 ci, the 4.300-inch stroke swings 521 inches, while the big 4.500-inch stroker will bulk this behemoth up to 545 cubes. The main journals are massive at 3.00 inches, so the cast crank and stock rods are not conducive to engine speeds above 6,500 rpm. Be forewarned that these stroker cranks also generally require a sizable investment in Mallory metal to balance properly, and that heavy metal will significantly drive up the total cost of a stroker swap.
Heads You Win
The stock iron 460 heads are a tease. On the intake side, the oval-shaped intake offers an attractive cross-sectional area for solid torque and horsepower potential along with acceptable valve sizes of 2.19/1.76 for the early castings. But just like its small-block cousins, the 460 exhaust ports are some of the most restrictive we've come across. Exhaust port flow is so poor that using a big cam will only kill power across the board. The long duration will hurt low-end torque, while the restricted exhaust ports will choke any chance of making power at the higher engine speeds.
Choosing a decent iron production head is a quest to minimize the corks. It appears the iron '69 C9VE or '70 D0VE casting numbers are the best heads to use for a budget performance engine. All iron production heads from 1968 to 1971 were closed chamber and 76cc. These are becoming increasingly hard to find, and we won't even talk about the iron 429 Cobra Jet and Boss 429 aluminum castings—they might as well have been buried with King Tut. In 1972, Ford went to an open 95 to 100cc chamber, which should be avoided as the worst of all the iron 460 designs because it has no quench area and is therefore prone to detonation. The '73-and-later heads went back to a closed-chamber configuration but with deeper 95cc/100cc chambers.
You can open up the exhaust ports on a stock set of heads to improve horsepower potential. But also consider the time and money you will invest in new valves, guides, a valve job, screw-in studs, guideplates, and purchasing all those parts. With all that you'll easily have between $900 and $1,100 invested in ancient iron and all the porting effort. If it's purely a budget approach, this is still roughly half the price of a set of new Edelbrock heads, for example. On the plus side, you are also going to trim at least 60 pounds off the nose of your car with the aluminum heads. The iron castings each weigh roughly 73 pounds complete, while the alloy Edelbrocks come in around 42 pounds each.
Besides the Edelbrock castings, there are other heads to choose from, as well. Perhaps the best is the Ford Racing Cobra Jet head, designed by Ford big-block guru Jon Kaase. These heads offer the most promising flow potential of all the aftermarket 429/460 heads. Kaase moved the valves to unshroud flow and change angles, and this head is especially powerful with larger-displacement engines like a 514 with a big cam. For more details on these heads, log onto jonkaaseracingengines.com. Another good set of heads come from Trick Flow Specialties (TFS). The company offers both track and street versions that are also worth investigating and are priced competitively with the Edelbrock castings.
Lube to Live
According to JGM, if the 429/460 has a weakness, it is the oiling system. For a low-rpm torque twister, the system works well. But for higher engine speeds where the horsepower lives, there are a couple of things that need addressing. Ford chose to lube the mains through the lifter galley, which means that the oil must pass through the lifters on its way to the mains and rods. This path is full of restrictions, which both reduces pressure and aerates the oil.
Much like the 351 Cleveland engines, the solution is to radically increase oil pressure to the tune of 70 psi. The higher pressure reduces foaming and ensures oil will make it all the way from the front-mounted oil pump back to the rear main. If oil starvation occurs, the rear main and rods will suffer the most. The solution requires a high-volume/high-pressure pump as well as a strong oil-pump driveshaft. JGM also recommends a solid distributor-gear drive pin (like an industrial rivet) instead of the hollow roll pin, because the stock pin shears off trying to drive the higher pressures. This pressure also demands a race-style filter to prevent bursting. Of course, this also means being very careful when the engine is cold to limit pressure-induced filter explosions when the oil is more viscous.
After dredging a complete 460 out of a '73 Lincoln Continental, we dissected it and delivered the block, crank, and rods to JGM. To create a solid foundation, we decided to also invest in a good short-block with a set of Federal-Mogul forged Speed-Pro flat-top pistons in case we decided to squeeze a little nitrous in the future. These pistons also gave us a pump-gas-friendly compression ratio when paired with the 95cc-chamber Edelbrock heads. Grubbs then supplied a set of rebuilt truck rods using ARP bolts to add a measure of durability. JGM also bored and torque-plate honed the block and oversaw machining our crank down 0.010-under to work with the Federal-Mogul bearings.
JGM has built a healthy 466 (see the Project 642 dyno chart) with completely ported iron production heads, but Grubbs reports that unless you enjoy a challenge, the effort really doesn't pay off in terms of the investment versus the ultimate power gain. We decided on a set of Edelbrock aluminum Performer RPM heads and a Performer RPM Air Gap intake as our route to power. These heads are intended to use roller rockers, so we plugged in a set of Harland Sharp 1.73:1 rockers to help with valve lift. This brought us to cam selection, and it just seemed a good idea to go with Edelbrock's entire Performer RPM package that uses a streetable flat-tappet hydraulic camshaft (see Cam Specs sidebar).
JGM then assembled the 460 with its recommended oiling-system changes and bolted the engine to the dyno. We also included a Holley 750-cfm mechanical-secondary carburetor with the HP body conversion (see that story elsewhere in this issue) to act as mix-master while also including a set of Hooker 131/44-inch chassis headers. This test was performed on Grubbs' own SuperFlow 901 engine dyno, but the cell does not leave room for a complete exhaust system. We also decided to test both Edelbrock hydraulic cams. The Performer-Plus cam is designed for torque, while the RPM cam offers more duration and lift for a major horsepower boost.
The Performer cam made some awesome torque with 523 lb-ft, but that same short cam timing only managed 406 hp. This spurred the JGM crew to swap in the larger RPM cam to which the 466 responded with a pump-gas-fed 503 peak horsepower at a mere 5,200 rpm while shaking the floor with 555 lb-ft of torque at 4,200 rpm. These numbers are actually very close to Edelbrock's power claims for their Performer RPM package. Even in a 4,000-pound car, this is good enough for low 12s to high 11s depending on the weather and altitude. This motor was incredibly easy to assemble and required no custom parts. Do it yourself in your garage. Bolt it in your favorite Ford, and you've got a tire-roaster.
Shim to Win
The JGM crew also clued us in on a simple valvetrain adjustment on these engines. The '73-and-later iron 429/460 heads all use a nonadjustable fulcrum-style rocker setup. Rebuilding one of these Lima engines usually involves removing the block and the heads. If using one of the tall-deck-height blocks, this could involve milling as much as 0.030 inch or more off the block deck. Retaining the fulcrum-rocker system with a shorter-deck-height or milled heads creates excessive lifter preload. Crane makes a kit (PN 99170-1) with 0.030-, 0.060-, and 0.090-inch-thick shims that will reduce lifter preload.
This minor change accomplishes two things. It is generally worth improved idle quality and, more important, minimizes the amount the lifter can "pump up" at higher engine speeds. While this may appear insignificant, a minimal hydraulic-lifter preload is generally worth power at higher engine speeds.
Networking at Its Best
There's always something new to learn, and one of the best things about the Web are sites devoted specifically to engines like the 429/460 Ford. While researching this story, we found a forum on network54.com. Find the search button and type in 385-series Ford, and you'll get to 460ford.com (we tried just entering www.460ford.com but it never works for us). Its tech forum gives members a chance to ask questions and get answers on these engines and related big-block Ford information. Check it out.
The Torque King
This is our 466ci motor built by the JGM crew with 9.6:1 compression, Federal-Mogul forged pistons, Edelbrock Performer RPM CJ aluminum heads, Performer RPM Air Gap intake, 750-cfm Holley carburetor, and 131/44-inch Hooker street headers. Test 1 is using the Performer-Plus Edelbrock cam. Test 2 employed the longer-duration Performer RPM grind. The motor made awesome torque and respectable horsepower with the smaller cam, but it may be a bit too short for the 9.6:1 ratio. Compression down at 8.6:1 would be better for the smaller cam. As you can see, Test 2 is where we make the power with the Performer RPM camshaft. JGM wasn't satisfied with 503 hp, so they tried a 1-inch open-plenum spacer and a set of 2-inch headers. Horsepower jumped to 514, and torque improved everywhere from 3,800 rpm on up, peaking at 565 lb-ft at 4,400. Run a 3.20 gear behind this beast and let it eat!
Test 1 TEST 2 TEST 3
RPM TQ HP TQ HP TQ HP
2,600 490 242 - - - -
2,800 497 265 - - - -
3,000 503 287 - - - -
3,200 517 315 - - - -
3,400 518 336 - - - -
3,600 522 358 530 363 - -
3,800 523 379 546 395 547 396
4,000 509 388 550 419 555 422
4,200 495 396 555 444 557 445
4,400 477 399 549 460 565 473
4,600 458 401 537 470 542 475
4,800 437 399 528 482 539 493
5,000 427 406 520 495 531 505
5,200 - - 508 503 516 511
5,400 - - 489 502 500 514
5,600 - - 468 499 478 509
Power/ci 1.12 0.87 1.19 1.08 1.21 1.10
Adv.Dur. Duration@ 0.050 Lift LSA
Performer-Plus flat-tappet hydraulic
Intake 272 194 0.460 110
Exhaust 282 204 0.480
Performer RPM flat-tappet hydraulic
Intake 290 234 0.556
Exhaust 300 244 0.581 108