The Stump Puller: A Methanol-Burning 572-Inch EFI Big-Block Ford

In the world of engine building, there are unique concepts and interesting ideas that keep the “juices” flowing for the goal of more power. But sometimes, there are some interesting ideas you have a hard time wrapping your head around. Business always centers around one major key factor: “The customer comes first.”

I am saying this because recently, I had the opportunity to perform a very interesting and unique engine build. The concept was for stump-pulling bottom-end torque at low-RPM, but also trying to squeeze some horsepower out on the top end. This wasn’t too complicated, until I was handed the build sheet with the components I would be using for the build.

Most of the time, I get to pick my own recipe for the bake-off, but this time, I had the ingredients handed to me. The build centered on the use of a 385-series big-block Ford 460 with some new top-end components that recently hit the market. It’s not uncommon to use new products in a build, but the components we are talking about — the cylinder heads and intake manifold — are definitely unique.

Looking At The Ingredients

The ultimate goal was to build a 572-cubic-inch motor made to operate down low, meaning that the objective was to see how much torque the engine could produce at 4,000 rpm. While most engine builds are based on acceleration performance and horsepower, this build was based strictly on torque. Oh, and did we mention that it will be running on methanol?

The plan is to run the engine on gasoline and fine-tune the combo using the Holley Sniper Stealth 4500 fuel-injection system. Once the gasoline tuning is complete, we’re going to switch the fuel to methanol and see how the Sniper performs as we fine-tune the engine again. This will give us a gasoline baseline to reference when we are looking at the performance on methanol.

The 572 cubic-inch short-block has a host of tricks in it, in order to be able to use an off-the-shelf rotating assembly and still meed the customer’s specs. The Eliminator engine blocks come in several configurations and strength ratings. This model is the Sportsman block, made from Compacted Graphite Iron, instead of the standard cast grey iron, which effectively doubles the block’s strength.

An important factor to consider is that methanol is very corrosive. Anyone who has experience in using methanol for racing applications knows there is more maintenance associated with using methanol. Most racers often flush the entire fuel system after each race because you do not want to leave it sitting unattended in the lines for an extended period.

When left in the fuel lines, methanol will start to form what looks like chalk. It doesn’t take long before the entire fuel system is clogged. The fuel tank, pump, lines, carburetor, and injectors can be stopped up entirely if they are left unattended. Fortunately we were able to find a preservative made just for methanol fuel that supposedly sustains it for several months.

The fuel preservative is added to the methanol and will not harm any of the fuel components if left unattended. This is where the Holley Sniper Stealth 4500 came into play. We wanted to see how it performed on methanol, and to see if it could handle the change in terms of fuel supply. Holley was on board, and we were off to the races.

Gasoline vs. Methanol

Something to point out here would be the ratio difference between gasoline and methanol. Of course all engines are different, but for the most part gasoline engines will operate somewhere around 12.5:1 to a 14.7:1 air/fuel ratio. This ratio means the engine should operate at peak efficiency with a mixture between 12.5 to 14.7 parts of air to one part of fuel.

When using methanol, this ratio will be somewhere around 5.0:1. An engine burning methanol will run using five parts of air to one part of fuel, which is more than double the amount of methanol required to make the same power as gasoline.

We knew the Sniper 4500 system would handle the fueling for gasoline, but it was unknown if it could handle the engine’s fueling needs on methanol. That wildcard further added to the uniqueness of this project.

The Top End First

Backward from the usual format, let’s start with details of the cylinder heads first.  Eliminator Products produces the cylinder heads under the part number F460. They are a unique cast-iron cylinder head design which features an “A460” intake port along with a big-block Chevrolet exhaust port.

The idea for the design came from the need for a performance-based cylinder head for truck pulling association classes. For these pulling classes, the rules generally dictate that the cylinder heads must be cast iron. While there are cast-iron reproduction cylinder heads available for the 460, there are none that satisfy the upper RPM range this project was looking to make horsepower in.

Features of the F460 cylinder head are pretty impressive. They originally got their start as an industrial head to be used with alternative industrial fuels (CNG, propane, methanol, hydrogen, ammonia, etc.). Later, the heads were fully CNC-ported and outfitted with two separate valve combinations.

The F460 intake port, as delivered from Eliminator products, flows a stout 380 cfm at .900-inch of lift. from the 320cc port. These particular heads have been worked over by Maloney Competition to flow in the 440 cfm range.

The first valve configuration is a 2.25-inch intake valve and 1.76-inch exhaust valve. The second features a larger 2.30-inch intake valve and smaller 1.72-inch exhaust valve. The heads retain the use of OEM guideplates, stud girdles, and valve covers. The stock fulcrum rockers can still be used as well. Flow numbers are strong with the intake ports flowing around 440 cfm.

As for the intake manifold, it is a new product just  released from Eliminator products. The intake is known as the “Big V” which is an aluminum high rise single plane manifold with and “A460” port flange. It is offered with three different style carburetor pads — 4150, 4500, or BHJ spread-style dominator. In recent testing, this intake manifold was shown to make substantial power gains in the upper bands.

However, high-RPM performance has tradeoffs, especially since we were looking to make good power down low. The problem is no one makes a dual-plane intake manifold with the A460-style intake flange. Since most A460-style cylinder heads are performance-based there has never really been a need for a dual-plane when using that style of performance head.

Maloney Competition also went over the Eliminator Big-V intake manifold to radius some of the runners. While this application might see a dual-plane intake perform a little better, such an animal doesn’t exist for these heads, along with a 4500 carb flange.

Maloney Competition Systems prepped the cylinder heads. . To keep the expense down, Bryan Maloney suggested the use of 8mm, 1.76-inch-diameter exhaust valves and 11/32-inch stem, 2.25-inch diameter intake valves. Because custom length valves can be pricey, this was an affordable way to use the valve diameters needed and lengths needed to achieve our desired spring height.

Maloney completed the combustion chamber work, valve guides and seats, then custom-made locating dowels to move the combustion chamber up in the bore by .050 inch. This was done to help promote airflow and valve fitment in the bore size.

While the F460 heads feature the A460-style intake ports, they feature exhaust ports from a big-block Chevrolet. While that might make header selection a little confusing, it is done for maximum flow characteristics from a cast-iron head.

Moving Down The Block

The engine block is also an Eliminator Performance piece. We used the “Sportsman” block, which is made of Compacted Graphite Iron, for approximately double the strength of a standard cast-iron piece. It features all of the amenities you’ve come to expect from an aftermarket block: priority main oiling, Siamese cylinder bores, blind head-bolt holes, and provisions for many OE accessories.

While the block can be ordered in different variations — such as deck-height, lifter-bore diameter, cylinder-bore size, and main-journal diameter — the engine block we assembled is based on stock dimensions. That means a 10.300-inch deck-height with 3.00-inch main journals and .875-inch lifter bores. The max bore on the Sportsman block is listed as 4.600 inches, but for this build we only took it to 4.500 inches.

The rotating assembly used in this engine build is pretty basic. The crankshaft is a 4.500-inch-stroke piece made by Eagle Specialty Products. Made from 4340 forged steel, the crankshaft utilizes standard big-block Ford 3.00-inch main journals, but the smaller 2.200-inch big-block Chevrolet rod journals. The connecting rods were also Eagle Specialty Products forged H-beam pieces, measuring 6.800 inches, center-to-center.

The Moroso fabricated race pan is an essential aspect for this engine, as oil control in this application is vital. Baffles keep the oil where it needs to be, and the unidirectional windage screen keeps oil splash-back off of the rotating assembly.

Dealing with big block Ford compression ratios can be tough because there  aren’t many choices. For instance, depending on the volume of the combustion chamber of the cylinder head  used you will usually have only two options. Somewhere in the range of either around 10.0:1 or 14.0:1. With our finished cylinder heads the combustion chamber was 83cc and we were trying to achieve around 11.0 to 11.5 compression ratio.

To keep from having to purchase a set of custom pistons we used a set of ICON pistons with a 35cc dish that have a compression height designed to be used with 6.700-inch connecting rods. We were able to mill .100 inch from the top of the piston and use a 6.800-inch connecting rod. This dropped our piston dish down to 23cc and our compression ratio ended up at 11.3:1.

Rather than ordering a custom piston, which could lead to increased cost and wait time, a set of 4.500-inch-bore ICON pistons with a compression height for a 6.700-inch rod were sourced. Then with a slight bit of machining, and using a 0.100-inch longer rod, compression was brought into the mid-elevens.

As for the valvetrain, one significant expense is the hydraulic roller camshaft. Most big cubic-inch engines are not built to perform at (or under) 4,000 rpm. As such, most cam cores are made to accommodate larger duration applications. You simply can’t take that style of cam core and grind it down to our desired specs, because you will grind past the hardness depth of the camshaft material.

Luckily, we were able to find a suitable cam core from Callies Performance and had Dimitri “Dema” Elgin of Elgin Cams in California custom grind the camshaft for us. Howards Cams hydraulic retro-fit roller lifters are paired with Elgin Industries stainless roller rocker arms.

Since this engine build is a different breed from a run-of-the-mill BBF, we wanted it to look good. We decided to paint the engine a traditional Ford Corporate Blue and use a Moroso fabricated race oil pan, oil pump and pickup along with its big-block Ford sheetmetal valve covers.

The key to the mix-and-match scheme to get the desired compression ratio with off-the-shelf parts is the Eagle 6.800-inch H-beam rods. In addition to the extra length, the forged H-beam design will hold up to the stout powerband this engine produces.

Turning Fuel Into Horsepower

With the engine together, we placed the Holley Sniper 4500 on the intake and wired the ignition and coil according to the instructions. If it had been our choice, we would have used the Sniper distributor for this application because it would allow us the option to build our own ignition timing curve. At the time of this build, the distributor wasn’t available.

We took the engine to the dyno to see what the end result would be. Remember something from earlier: the cylinder heads have big-block Chevrolet exhaust ports. So to fit the dyno, we used a set of long-tube headers with 2-inch primaries to a 3-1/2-inch collector, originally designed for a 1970 to ‘81 Chevrolet Camaro.

Off-the-shelf parts were available for the valvetrain, since as far as that portion of the engine is concerned, it's just another big-block Ford. A set of Howard's Cams hydraulic retro-fit roller lifers ride on the custom camshaft and Elgin Industries stainless roller rocker arms translate the lift from the cam to the valve.

After everything was hooked up and checked, the engine roared to life. We were all surprised because this was new territory for us using this engine combination. The throttle response was incredible and the engine idled very well with excellent manifold vacuum.

For the dyno pulls, we wanted to graduate through the RPM ranges slowly. The Sniper system has a self-learn function, so the more you drive it the more it learns and adapts, based on the data you enter into the setup screen before you crank the engine for the first time.

With this style of fuel injection each pull was impressive. As the fuel tables changed and the correction factor got lower, the torque and horsepower began to reach their peaks. The peak torque of the engine was at 4,200 rpm while the horsepower topped out at 5,200. This is doubly impressive considering the intake choice was not the best one for this application but was all that was available.

The Holley Sniper EFI Steath 4500 is a bolt-on EFI system, capable of supporting 1,500 naturally aspirated horsepower on gasoline without a laptop. However, we wanted to know if if would work running methanol instead of gasoline.

With the gasoline baseline established, we switched fuels and plugged the laptop into the Sniper ECU. The methanol fuel required tuning from a laptop because of the air fuel ratios we were targeting (around 5.0:1). They were too far outside of the Sniper’s standard realm. However, the Sniper was able to provide all the fuel volume we needed, which was a concern, initially.

After testing the methanol fuel, we left the engine sitting on the dyno for over a week to see the effects of the fuel preservative. With our fingers crossed the engine fired and ran just as well as it did the previous week.

On gasoline, once the self-learning completed doing its thing, we saw peak power of 708 horsepower at 5,200 rpm, and peak torque of 787 lb-ft at only 4,200 rpm.

With the laptop-tuned methanol, the power and torque peaks remained at the same engine speeds, but with an additional 36 horsepower and 44 lb-ft of torque on the graph. That brings the final methanol-fueled numbers to 744 horsepower and 831 lb-ft — or 5.1-percent and 5.6-percent increases over gasoline respectively.

Genuinely surprising was that this engine had such a generous idle and quickly roared to life upon acceleration. Not a bad deal at all for a mild short-block, off-the-shelf heads, and a bolt-on EFI kit, running a fuel for which it was never really designed. That the Holley Sniper is a bolt-on, methanol-capable system kind of changes the game in our eyes.

By all forms of measurement, this project was a success. The engine hit all of the customer’s power and powerband goals (744 horsepower at 5,200 rpm and 831 lb-ft at 4,200 rpm), while proving  the Sniper Stealth 4500 EFI system can run on methanol — albeit needing to be tuned via laptop instead of the handheld programmer.

Article Sources

About the author

Bob McDonald

I have always had a passion for the internal combustion engine. I have been an automotive and diesel technician for over 30 years. I enjoy building high-performance engines and admire in-depth research and development.
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