Building 400hp Into A 5.0L Small-Block Engine - Down-Low 5.0
How To Make (Almost) 400 HP For (Almost) $1,000.
From the October, 2009 issue of Muscle Mustangs & Fast Fords
By Richard Holdener
Is it really possible to build...
Is it really possible to build a low-buck, aluminum-headed 5.0L that will pump out 400 hp?
Times are tough for many Mustang enthusiasts. In these uncertain economic times, we are forced to watch every penny, even though maximizing power is always high on the priority list. We all crave more power and better handling, but who has the big bucks for exotic parts? When times are tough, trade offs become necessary and in some cases, this involves trading expense for either knowledge (of the sort you find in the pages of MM&FF) or good old-fashion elbow grease.
For this engine build, which we'll call "Down-Low 5.0," we traded both. The premise or recipe was a simple, albeit popular, one. Take one 5.0L Ford and select the most cost-effective components in order to achieve our seemingly conflicting goal of power and economy. On the power side, we selected 400 hp as an impressive but reasonable output for our small-block 5.0L Ford.
Building a 302-inch small-block to produce 400 hp is really no big deal, but doing it for what amounts to chump change is decidedly more difficult. This meant building our 5.0L with a ceiling of just $1,000. Given the fact that $1,000 is less than the typical cost of a set of aluminum cylinder heads, reaching 400 hp for a grand total of $1,000 looks pretty impressive, not to mention somewhat difficult. Now let's throw in the fact that the $1,000 price tag must not only include the cost of said aluminum cylinder heads, but the entire 5.0L engine to boot. Have we lost our minds?
A little recon and planning...
A little recon and planning netted a complete 5.0L motor for the paltry sum of $100. Westech's Big Ernie removed the fuelie motor for us on a half-price-sale weekend.
Naturally the 400 hp motor was not going to be some off-the-shelf crate motor assembly, unless you count the shelf at your local wrecking yard. Remember, we said that it might be necessary to trade cost for some elbow grease. In this case, the elbow grease came in the form of some computer legwork through the local sites for Craigslist and Recycler, as well as a few trips to a nearby wrecking yard.
Calling first, we found a few yards that offered complete motors for just $200 (plus a core of $45). Of course, the $200 motors were still installed in the vehicle, so this meant trading elbow grease for the additional cost savings. Always up for a quickie R&R procedure, we ventured off to our favorite Pick-A-Part in search of a low-buck but hopefully well-running 5.0L. Believe us, running motors (even good running motors) are out there for the taking. Given the sheer production numbers, this is especially true of 5.0L Fords. As luck would have it, the local Pick-A-Part had special sale weekends, when everything in the yard was 50 percent off. This brought the sale price of our used 5.0L down to just $100 (plus core). Available in both cars and trucks, our only concern was to locate a good-running 5.0L motor with everything intact. Though we would be replacing the fuel injection with carburetion, the factory injection system would help serve a later purpose.
Here are a couple of tips that might help you separate a usable junkyard 5.0L from the rest of the junk. First off, make sure that the motor has everything present that you will need to install in your vehicle. In most cases (like ours), the cost of the motor included everything from the air filter to the oil pan, the fan to flexplate (or flywheel). This also included things like the motor mounts, starter, and all of the accessories, though none of these would be run on the engine dyno.
Since we plan on running the...
Since we plan on running the motor with a carburetor, off came the factory injection. This was later traded to our machinist for a used 750 Holley carb and surfacing of the Pro Comp heads.
Though fine for the stock...
Though fine for the stock 5.0L, the stock E7TE heads were hardly what you'd call performance pieces. The stock heads flowed 155 cfm on the intake and 112 cfm on the exhaust.
Looking to maximize power,...
Looking to maximize power, we opted for the 210cc heads from Pro Comp. The Pro Comp heads offered a unique combination of performance, weight savings, and affordability, making them perfect for our project.
Knowing we'd never reach the...
Knowing we'd never reach the 400hp mark with the stock 5.0L cam, it was replaced with a Track Max hydraulic roller cam offered by Trick Flow Specialties. The Track Max cam offered a 0.499/0.510 lift split, a 221/225 duration split, and a 112-degree lobe separation angle.
After checking out the major components, it is time to look specifically at the motor to ascertain its health and viability as a candidate for the project. For starters, check the coolant, oil and spark plugs. The oil and coolant have likely been drained, but check inside the radiator cap or even in one of the radiator hoses for signs of antifreeze. Fresh antifreeze is a good sign; a rusty radiator or thermostat housing is not. If the oil has been drained, smell the dipstick (does it smell like burnt oil?), and even go to the trouble of removing the drain plug on the oil pan. Does the residual oil resemble sludge or is it clean? Don't confuse high mileage for abuse, as dark oil can mean that the motor simply needed an oil change and not a bearing change. Don't be afraid to yank a valve cover to verify the condition of the engine, as going through all the trouble of pulling a motor only to find out that it is a junker is huge waste of time and energy.
Check the spark plugs for signs that the engine was burning oil. Avoid engines with oil-contaminated plugs, but don't assume fresh plugs are the ultimate sign of a well-preserved motor either. If the oil and plugs pass inspection, try spinning the engine over with a ratchet on the crank pulley. If it spins freely with no binding, chances are the bearings are in good shape. If you are allowed to bring a battery in to crank the engine over, by all means perform a compression check.
To keep costs down, the factory...
To keep costs down, the factory hydraulic roller lifters were reused. We had no way of knowing the mileage on the motor, but the factory lifters appeared to be in good shape.
With tool chest in hand, we headed off to the wrecking yard in search of the perfect specimen for our Down-Low 5.0. Our trip was very successful, though the wrecking yard was packed with patrons on this particular sale weekend. On our first recon trip, we even purchased a pre-sale ticket that allowed us to get in early ahead of the crowd. Special thanks goes to Big Ernie at Westech for actually yanking the motor.
Not surprisingly, 5.0L Fords weren't hard to come by. There were trucks, T-birds, and more than a few 5.0L Mustangs in the wrecking yard. All we had to do was locate a suitable candidate that we hoped was in good running condition. After removing the valve covers and plugs of a few different motors, we located a good choice in the form of a 5.0L H.O. from a T-bird. The motor spun freely and seemed healthy.
After unbolting the motor mounts, fan shroud, and trans bolts, the 5.0L was free. Before paying for the motor, we took the liberty of replacing the factory TFI distributor with a Duraspark unit from a carbureted 302. We had more than enough 5.0L fuelie distributors back at home, and needed the carbureted distributor since we planned on ditching the injection system.
According to Pro Comp literature,...
According to Pro Comp literature, the 210cc intake ports flowed 262 cfm at 0.700 lift. At the 0.500-inch lift offered by our Track Max cam, the Pro Comp heads flowed 233 cfm, or more than enough to support our goal of 400 hp.
As the owner of an original '88 5.0L LX, I find it amazing that you can go down to the wrecking yard and pick up a complete 5.0L motor for the paltry sum of $100 (on sale day). The iron-headed 5.0L motor was quite a find, as it ensured we had a hydraulic roller cam, decent compression ratio, and a short-block that would easily run to 6,500 rpm. The factory E7TE iron heads were to be replaced with low-buck aluminum castings. That's right-an aluminum-headed, 400hp 5.0L for $1,000.
The wrecking yard actually offered us a warranty (for an extra $12) that allows us to return the motor for a replacement if it is internally damaged and unusable. As it turned out, the warranty money would have been wasted since our motor was a healthy customer. If offered, the warranty is still cheap insurance. Sure, you'd have to pull another motor, but you wouldn't be out the $200 ($100 on sale day) if you found a spun bearing or some other malady that might keep you from using the motor immediately.
The final test was to check oil pressure. A new oil pump was not on the budget, and we were hoping to get by with the stock pump. After filling the pan with Lucas synthetic 5W30 and spinning the oil-pump drive shaft with an electric drill, we were rewarded with nearly 60 psi of cold oil pressure. It looked like our Down-Low 5.0 was in business.
The exhaust ports measured...
The exhaust ports measured 70 cc and flowed 177 cfm at 0.700 lift (170 cfm at 0.500 lift).
The Pro Comp heads came complete...
The Pro Comp heads came complete with valvesprings, retainers and a 2.02/1.60 stainless steel valve combination.
Though offered with 64cc chambers,...
Though offered with 64cc chambers, we took the liberty of milling the heads to achieve 60cc chambers. This increased the static compression ratio of our 302 to 9.7:1.
The heads from Pro Comp also...
The heads from Pro Comp also included rocker studs and guideplates. Since the factory rockers could not be run on the Pro Comp heads, we purchased a set of Pro Comp roller-tip rockers (just $55).
The 5.0L was originally rated at 225 hp and 300 lb-ft of torque. Though adequate back in the day, it is hardly what you'd consider a powerhouse compared to the 4.6 Three-Valve or other modern engines. To reach our goal of 400 hp, we needed to address the fundamental restriction to power production-induction flow. First on the list was a set of cylinder heads. We considered simply upgrading the existing heads with hand porting, milling, and a valve job, but soon dismissed this idea after weighing the cost versus potential power gains offered by the stock heads.
We were looking at a machining bill of nearly $350 to rework the stock heads, so we decided to purchase a set of new aluminum heads from Pro Comp. Pro Comp offered its Ford heads with both 190cc and 210cc (as-cast) intake ports. It even offers a version with the smog passages drilled and ready to accept the smog pump hardware. Since the cost of the heads was the same, we decided to go big and opted for the 210 heads. They might come in handy if we improve the motor at a later date or slip a new 347 stroker kit under the shiny aluminum heads.
Since we were swapping the...
Since we were swapping the heads, we required new gaskets. Pro Comp supplied this set for the 302 for just $25. Were we running boost or nitrous, we might step up to something other than a replacement head gasket, but these worked perfectly on our mild (normally aspirated) buildup.
The Pro Comp aluminum heads also featured 70cc exhaust ports and a 2.02/1.60 valve combination. The big news is, of course, the aluminum construction (less weight than our iron factory heads) and the significant increase in port flow-not to mention the new valves, seals, and a fresh valve job. Where the stock E7TE heads struggled to reach 160 cfm, the Pro Comp heads flowed over 260 cfm on the intake and 177 cfm on the exhaust side. These flow numbers offered by Pro Comp can be increased significantly through CNC porting for another $400-$550. Best of all, the 210cc as-cast aluminum heads can be had (with a little haggling) for less than $600 on Ebay. (We got ours for $540.)
The one potential downside to running the Pro Comp heads is the need for adjustable rocker arms and different pushrods, which further increased our budget. A set of new (hardened, but not chromemoly) pushrods set us back just $29. It was an unnecessary expense to step up to the chromemoly pushrods, but hardened pushrods were mandatory for use with the guideplates supplied with the Pro Comp heads.
For induction chores, we also went to Pro Comp, which offers one of the very best carbureted intakes available for the 5.0L, the Parker Funnel Web. The single-plane Funnel Web offers plenty of flow and power potential, and was available for as little as $125 through Ebay stores. Having tested these Parker Funnel Webs many times, we knew they worked well on modified 5.0L motors and would certainly help us reach our goal of 400 hp. Given the price, they represented one heck of a performance bargain.
We did our best to clean the...
We did our best to clean the years of oil and dirt off the wrecking-yard motor before stripping it down to the short-block.
After heads and intake, it was time for the camshaft. Obviously the stock 5.0L cam was not going to let our motor make anywhere near 400 hp, despite the improvements to the induction system. With cost still a major issue, we let our fingers do the walking over the magic keyboard and found some Track Max hydraulic roller cams offered by Trick Flow Specialties through Summit Racing for $164. The Track Max cam offers a 0.499/0.510 lift split, a 221/225 duration split, and a 112-degree lobe separation angle. We wanted to step up to the larger 224/232 Track max cam, but were concerned about piston-to-valve clearance with the factory pistons. In our quest to save money (it was, after all, a hydraulic roller), we simply reused the factory roller lifters.
After the compression and oil pressure test, the wrecking-yard wonder was disassembled down to the bare short-block. We installed the new hydraulic roller cam using Lucas Oil assembly lube. Although we had no way of knowing the mileage on the used motor, the timing chain appeared to be in good shape and had minimal slop. Normally we'd change this, but we elected to save the $25-$50 cost of the replacement. We coated and installed the old lifters, then installed the newly machined Pro Comp aluminum heads.
Before leaving the wrecking...
Before leaving the wrecking yard with our new fuelie motor, we took the liberty of swapping out the stock TFI distributor for its carbureted equivalent.
With a little horse trading, we were able to secure not only a used Holley carb, but also managed to have the Pro Comp heads surfaced in exchange for the complete EFI system. The owner of our machine shop was in need of a stock 5.0L EFI system for a customer and had a used Holley 750 double-pumper in his shop, just looking for a new home. We surfaced the Pro Comp heads to bring down the chamber size from 64 cc to just 60 cc. This bumped the static compression ratio of the 302 by roughly 0.5 point. For gaskets, we again turned to Pro Comp, which offers a complete set for $25.
The heads were installed using the stock head bolts. Next came the new, hardened pushrods and Pro Comp roller tip rockers. For about $50 more, we could get a set of true roller rockers, but we were budget minded on this motor and opted for the roller tip rockers instead. Running the stock stamped-steel rockers on the Pro Comp heads was not an option, as the bolt-down rockers would not work with the rocker studs supplied with the heads. Besides, we hated the idea of running stock rockers on a performance motor. We then installed the Funnel Web intake, followed by our used Holley 750 carb. Planning ahead in the wrecking yard provided the necessary distributor, which we used with the stock plug wires (ours were in decent shape after a quick cleaning).
The final step was to bolt on a set of 1 3/4-inch Hooker Super Comp headers (not included in the buildup cost) and Down-Low 5.0 was ready for some dyno action. The final bill for all the madness was $1,064 after trading the EFI system for the Holley carb and surfacing. If we had to purchase a new Holley carburetor, figure on another $275 for a 750-cfm vacuum secondary model. Even if we had to spend the extra $275 for a new carb, that is still chump change for a complete aluminum-headed performance 5.0L!
Induction chores are handled...
Induction chores are handled by a single-plane Funnel Web intake manifold. Designed to shift the torque curve, the Funnel Web sacrifices low-speed torque for high-rpm power. In truth, a dual-plane intake would be a better match for street use on this combination, but we were determined to make 400 hp.
The rings and bearings had long since been acquainted, but the same could not be said for the new cam and roller lifters. Given the roller profile, a break-in procedure was not mandatory, but we elected to give all the new components time to get properly acquainted before letting the hammer fly. The oil pressure looked steady at 55 psi, and the motor sounded plenty healthy breathing through the 3-inch dyno exhaust.
The initial pulls showed plenty of promise, with Down-Low pumping out more than 300 lb-ft of torque at 3,000 rpm. We experimented with timing (eventually settling on 35 degrees) and minor jetting to the used Holley before letting the hero pull. With a safe air/fuel mixture in the high 12s, the 302 eventually pumped out 399 hp at 6,000 rpm and 363 lb-ft of torque at 5,200 rpm.
The single-plane intake meant power production was kept higher in the rev range (a torque peak of 5,200 rpm is pretty high), but the little 302 did manage to exceed 350 lb-ft from 4,600 to 6,000 rpm. In hind sight, a dual-plane would likely be a better choice for a street-driven 302, but we wanted the big number and only wanted to spend a grand doing it. In the end, we made 399 hp for $1,064. If that doesn't qualify as a Down-Low 5.0, we don't know what does.
This used 750 Holley double-pumper...
This used 750 Holley double-pumper was acquired from our machinist in trade for the factory EFI system.
Once on the dyno, the wrecking-yard...
Once on the dyno, the wrecking-yard 302 pumped out 399 hp at 6,000 rpm and 363 lb-ft of torque at 5,200 rpm. Not bad considering the total bill for the motor was $1,064.
The combination of the Pro...
The combination of the Pro Comp 210 (as-cast) aluminum heads, TFS Track Max cam, and Funnel Web intake literally transformed our wrecking yard wonder. Originally rated at 225 hp and 300 lb-ft of torque in fuel-injected form, the carbureted 5.0L pumped out 399 hp and 363 lb-ft of torque. While a 400hp 302 is not exactly ground breaking, the fact that we were able to build this motor for $1,064 is pretty impressive. Especially when you consider the fact that this included the cost of the motor! Torque production from the 302 exceeded 300 lb-ft from below 3,000 rpm to redline, and managed to exceed 350 from 4,600 rpm to 6,000 rpm. There is certainly more potential in the Pro Comp heads, but wilder cam timing would likely require notching the pistons.
|Down-Low 5.0L Pricing|
|Pro Comp heads ||$540|
|Parker Funnel Web intake||$125|
| Complete 5.0L Fuelie, Pick-A-Part (wrecking yard)||$100|
|Core charge for motor||$20|
|Gaskets set, Pro Comp||$25|
|TFS Track Max cam||$159|
|Pro Comp roller-tip rockers||$55|
|Elgin hardened pushrods||$35|
|"Down-Low 5.0" Total Build Cost||$1,064|
|E7TE Iron Versus Pro Comp 210, As-Cast|
|Intake Airflow Data CFM @ 28 Inches|
|Lift||E7TE||Pro Comp 210|
|E7TE Iron Vs Pro Comp 210, As-Cast|
|Exhaust Airflow Data CFM @ 28 Inches|
|Lift||E7TE||Pro Comp 210|