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High-Performance Crate Engine Buyer's Guide
Plan to order a high-performance crate engine? Here's what you need to know to do it right.
The horsepower-by-mail concept has been around for years, but never has the market been so hot--especially when it comes to Ford V-8s. Today, crate engines are the rage, ranking right up there with nitrous and blowers. And, like ordering a pizza, you can literally dial the phone or click your mouse, plunk down your plastic, and a driver will deliver one with all the toppings. This includes stock-type, short- and long-blocks right up to balls-to-the-wall race engines making over 1,000 hp.
Before you get started, there are dozens of variables you'll need to sort out. Naturally, you'll want horsepower, but obviously you have a budget to consider, and your level of spending will directly relate to the number of ponies under the hood. While most of us have dreams of 700 hp, chances are your street-driven LX will be much more enjoyable to drive with a 450hp, 10.0:1 engine that runs on 92-octane fuel. Higher power levels require a stout driveline and more frequent maintenance. There's also more tuning difficulty and higher operating costs. In other words, sometimes less will give you more.
"When we sell an engine, we try to make sure it meets the customer's expectation," says Chris Huff of Coast High Performance. "That's the most important thing. We once had a guy who wanted a Dart block, but wanted to use a stock cast crank and stock rods, and that just doesn't make sense. In his case, a stock block would do, and that's what we recommended to him. It also saved him a bunch of money."
So, exactly how can you get the right engine for your car or truck? You can start by answering a few questions. First, determine what you'll be doing with the car or truck. What type of vehicle is the engine going to be put in? Do you plan to drive it on the street and use 92-octane pump gas? Will it need to idle for long periods and not overheat? Will you be adding a supercharger or nitrous? Are you using an automatic, and if so, which stall converter? Or will it be a stick? How stiff will the gearing be? Lastly, how much power do you expect it to make, and how quick do you want your vehicle to be?
The answers to these questions are important because they will help you determine the best combination of parts for your applica-tion. For instance, if you have a 3,600-pound street Mustang, you won't want a small 302 that makes peak horsepower at 6,500 rpm. You might opt for a torquier combination like a 408 stroker or a smaller engine with a Roots-style blower. There are dozens of options to consider, and if you don't have the answers, you could easily pick the wrong heads, cam, compression ratio, or induction, and go down the wrong path. Thankfully, MM&FF is here to help.
Any engine--crate or otherwise--begins with the block. The block is the foundation because it houses the rotating assembly (consisting of the crankshaft, connecting rods, and pistons), the cylinders, and passages for coolant and pressurized oil. Many blocks have provisions for installing a camshaft. But the block's job doesn't end there. Cylinder heads are bolted tightly to the block, and their retaining hardware must keep the heads sealed, even under the extreme pressures of combustion. There's also a variety of front engine access-ories mounted to the block, all of which vibrate, twist, and/or turn. And let's not forget the transmission and the engine mounts that hold it all in place. Whew! As you can see, the block serves many duties, but its biggest jobs are to contain the rotating assembly and to deal with the immense forces, vibration, and friction.
When it comes to stock, late-model, 5-liter blocks, there most certainly is a limit. When you double or triple the level of power, cracks can develop and failure occurs. As horsepower or rpm is increased, so are the forces on the block, which is why it's necessary to upgrade the engine block when you get to a certain horsepower level.
But what is that level? Unfortunately, there really is no accurate answer. It all comes down to the preparation and the usage. Some stock blocks have lived well past 600 hp, others crack while making 350. The fact is, the stock 5.0 blocks are of the thin-wall cast type and are susceptible to cracking in the main web area. It is this author's belief that excess vibration and detonation will kill a block quicker than excess horsepower will.
Like the block, the crankshaft is also subject to some unbelievable forces. The crank has the dubious job of converting the up and down motion of the pistons into rotational force at the flywheel. There are a few different materials used to manufacture cranks. The most common is nodular cast iron, which is mostly used in stock engines. When prepared properly, a stock crank can handle 400-500 hp, assuming the engine is not revved regularly past 7,000 rpm. Of course, a quality balance job and lightened rotating assembly goes a long way to keeping a crank alive. Also, deburring the casting will reduce the chance of a crack starting, and chamfering the oil holes also helps.
Forged steel cranks are certainly stronger than nodular cast iron and should be used if you can afford one, or if you plan to buzz the engine past 7,000 rpm. In either case, you should spend the money to have a used crank Magnafluxed to ensure there are no cracks. Last on the crank-shaft list is the billet steel crank. These are cut from a steel billet and are the strongest of the crankshaft lot.
Along with a good crank, you'll want to purchase quality connecting rods, wristpins, and forged pistons for any performance appli-cation. We always suggest buying the best parts you can afford, and strongly advise not buying inferior parts or used parts unless you know their exact history. You will only wreck them and have to spend more cash on the right parts down the line.
While the bottom-end of the engine provides the strength, the top-end provides the power. Airflow into the cylinders (combined with a proper fuel mixture) is where the power comes from, so you'll need a combination of cam, heads, and intake (and power adder, if applicable) that works in unison. It's downright impossible for us to offer up any single combo that will work for each and every person who reads this article, so you'll be left on your own to research and pick those parts. But do understand that you probably don't need as much cylinder-head flow or camshaft lift as you think. By keeping on the small side, the airflow will maintain port velocity, and that equals volumetric efficiency (VE). And good VE equals torque, which we all know is the key to having a strong street engine. This is yet another reason to deal with a Ford-specific engine shop.
"Fords are our mainstay, so we're well versed, and we'll be able to help you select the best cam or heads for your combination," says Huff of CHP. "A typical rebuilder might not know which manifold is best, or he may not have tried a variety of aluminum heads on different engines. Or, he may have to order parts including all the little stuff, where we have it all in stock. In addition, our sales staff is made up of Ford racers who know what you're trying to achieve.
"Generally, it takes a week or two to get an engine. We stock short-blocks and then dress them as needed for each customer. That way, we can get a fix on the combination."
Huff makes a great point about dealing with a Ford-specific shop, as this can help you achieve the level of performance and driveability you desire on the first try. And it can save you months worth of time, as it's generally quicker to get a crate engine than to wait for your engine to be torn down and rebuilt. Not that your local builder is incapable of building a good mill, and doing so in a reasonable amount of time, but we've seen some real horror stories where people have waited months while the builder waits for parts or works on other projects.
Aside from the simple fact that you may just need a new engine, one reason for the popularity of crate engines is that many suppliers offer an array of stroker kits. A stroker kit increases the cubic-inch displacement by lengthening the stroke of the crankshaft arm, which extends the distance, or stroke, of the pistons in the cylinders. While boring an engine 0.030-inch may add two or four cubes, replacing the 3.00-inch stroke factory crank with a 3.40-inch stroke crank can add 40 ci. And it's awfully hard to beat those extra cubic inches.
But you should also beware of those cubes. Many Mustang owners like the idea of a Windsor-based 392 or 408, but they don't realize that when swapping from a 302 with an 8.200-inch-deck block to a 351 (with a taller 9.2- or 9.5-inch deck-height block), it requires different headers, a new distributor and intake, and often a new hood. If making those changes is an issue, a better option may be a 347, which gives you extra cubes, yet dimensionally, it's like a 302.
Fortunately, there are enough Ford-smart shops in the crate-engine market, and they can set you up with everything from a stock-type 302 to a wild 5.4, four-cam killer.
One of the leaders is Roush Engines, which has a strong line of street and race powerplants. "I don't look at what we do as crate engines, per se," says Todd Andrews of Roush. "It's like having a custom engine that we've scienced out for you. We hand-build each engine and use many of our own parts, right down to the timing pointer. Everything is brand-new, and every engine comes with a two-year/24,000-mile warranty. We're never going to be the cheapest, and we're not always shooting for the highest horsepower. We're going after a big linear torque curve because with our packages it's all about driveability."
Many of the Roush packages come complete, right down to the front engine dress, a serialized placard that can be affixed to the vehicle, and all the build information.
We also spoke with Joe Amato of Downs Ford Motorsport, which sells both Ford Racing's motors and Downs' own line of crate powerplants. "We offer budget-minded 306 short-blocks built to our own specs," he says. "The blocks are stock production roller blocks that are hot-tanked, Magnafluxed, torque plate-honed, and bored 0.030-over. Decks are squared and equalized. The blocks are also chamfered, align-honed, and cleaned. We use forged pistons with valve relief cuts and moly rings. The rods are stock, but we have them reconditioned. They are also hot-tanked, Magnafluxed, shot-peened, and resized, and we use ARP Wavelock rod bolts.
"The stock cranks are hot-tanked, Magnafluxed, shot peened, chamfered, and ground 0.010 inch under. The whole assembly is computerized balance to +/- 0.5g, and we use ARP main bolts. The assembly does not come with a cam or chain. They run $1,595 and will handle up to 475 hp, but the power is limited only by the stock block.
"To make a long-block, we use a GT-40X heads with ARP bolts, Fel-Pro Graphite head gaskets, an E303 cam, new lifters, a new double-roller timing chain, lifter hold downs, FRPP pushrods and 1.6 rockers, and custom Downs Ford valve covers. These run $3,995 and are rated at 350 hp."
By now, you may have gathered there are quite a few crate motor builders--some with pretty impressive stuff. So, if you're in the market, do the research and come up with a combination that will provide the necessary power. But don't discount the need for driveability, as that's what will make your ride fun to drive.
The 10 Commandments Of Crate Engines
1. Not all engines are created equally, even if they share the same parts. Stick with a reputable builder even if it costs more. And purchase the best parts you can afford. It's easy to cut corners on preparation and some of the machining processes. Remember, you get what you pay for.
2. Know what you are ordering. Picking cams and heads that are big may sound cool on paper, but it could negatively affect driveability and power. Most street engines will provide better performance if they are big on low-mid-range torque rather than a big horsepower number.
3. It's OK to swing for the fence and order that killer 700hp engine package, but realize you'll need the rest of the combination to make it work. This includes a quality fuel system, transmission, rear, suspension, and chassis. Also, you should know how to tune properly to keep it all in one piece.
4. Always consult the builder before firing the engine for the first time. Every engine builder has specific recommendations for priming the oil system and breaking in the engine.
5. Know your parts. For instance, short-block is the term given to an engine with only the rotating assembly (crankshaft, connecting rods and pistons) installed. A complete short-block will generally include the oil pump, pick-up and pan, camshaft, and timing chain assemblies. A long-block includes the cylinder heads. A complete long-block will normally include lifters, pushrods, and rocker arms.
6. Know your strokers. A stroker engine utilizes a crankshaft with a longer-than-stock stroke on the connecting rod journals. This increases the cubic-inch displacement of the engine and generally adds power.
7. Be specific when asking questions, especially when it comes to delivery, tuning, and oil type. For instance, know what company will be delivering your valuable engine, how much it will cost, and how much it is insured for. Ask whether the truck will have means to unload your engine once it arrives. Some trucks have a hydraulic lift gate, others require you use a forklift or engine hoist to remove the engine. As far as tuning, ask what carb or injection will work best and what exhaust you should go with.
8. Ask the builder to provide a buildsheet that lists the tolerances, the tightening specifications, and all the part numbers. This will be helpful when it comes time to rebuild or freshen the engine with new rings and bearings. If you ever sell the car, you'll have documentation that could add to the value of the engine.
9. Every engine begins with the block, and we recommend purchasing the best one you can afford. Modular blocks are strong and can handle over 600 hp quite easily. Older 5-liter blocks aren't quite as strong, but they are inexpensive. For some, it may be better to use a $200 stock block and replace it down the road than to spend $1,800 on a race block. Thankfully, the aftermarket is responding to this issue, and there are some affordable alternatives such as the Ford Racing Performance Parts 302 Sportsman block and the soon-to-be-released Boss 302 block, also from FRPP. Other aftermarket companies selling blocks are Dart and World Products.
10. Lastly, smash the gas and have fun!