 |
Be realistic with the buildup of your street machine. Choose modifications that are budget minded, reliable and offer great all-around street performance. A mild small-block V8, good suspension and nice wheels will generate a more fun-to-drive package than a car fitted with a tempermental 12.5:1 engine delivering power to a rough riding, race-type chassis. |
If you&8217re working on a budget, one cost-effective way to build a new engine is to order a low-buck engine kit from a mail-order parts company, such as those found in Car Craft. |
Open-plenum intake manifolds deliver great high-rpm horsepower, but a dual-plenum intake is usually a better choice for a real-world, daily driver street machine. Decide how your car will be driven most of the time, and select engine components accordingly. |
There is a wide variety of books and videos designed to aid the first-time engine builder through a street machine engine buildup. Classic Motorbooks (800/826-6600) is a great mail-order source for automotive- related literature. |
Rather than guessing at which parts will work properly together and deliver great power when selecting components, you may wish to choose a proven power parts combination. This Total Power Package from Edelbrock includes an intake, a carb, cylinder heads and a cam/lifter combo that are specifically designed to work together. |
Although it may cost a few extra dollars, you should always have the cylinder block honed with a torque plate installed if possible, which delivers a more accurately machined cylinder bore. |
A simple at-home machining process involves tapping all of the bolt holes on the cylinder block. The tap straightens the bolt hole threads and removes debris from the hole. |
Decking a cylinder block produces a more even, flatter deck surface, which promotes better cylinder sealing. Only machine off enough block material to make the deck surface flat. |
Before assembling the engine, always wash the cylinder block, crankshaft and rods with soapy water. Use a bottle brush to clean all of the small holes and galleys in the block. |
The outside of the cylinder block should be painted with a high-temp paint. Coating the lifter valley with a high-temp, oil-resistant paint helps increase top-end oil flowback. |
Align-boring the cylinder block mains helps reduce crankshaft binding, which can increase bearing wear, rob horsepower and, in some cases, cause bearing failure. |
If money allows, upgrade to brass freeze plugs in place of the stock steel plugs. Apply sealant to the edges of the plug, and then tap it into the cylinder block until the plug&8217s outer edge is flush with the block. |
Whenever you&8217re not working on the engine, be sure to cover it to prevent dust and dirt from accumulating. |
A few pieces of rubber hose over the ends of the rod bolts help prevent scratches on the cylinder walls and/or the crankshaft rod journal. |
Torque the main cap bolts incrementally in the proper sequence using a professional-quality torque wrench. |
Install the main bearing in the cylinder block dry. Then, add a coating of assembly lube to the top of the bearing. |
Carefully set the crankshaft into place making sure not to damage the main bearings. If you&8217ve opted to install main studs in place of the stock main bolts, add main bolt covers (or pieces of rubber hose) to the ends of the bolts to prevent gouging the crankshaft journals. |
Camshaft selection is critical to an engine&8217s performance. Never try to reuse old lifters and a timing chain set in an attempt to save a few bucks. |
As with the camshaft, be sure to apply cam lube to the sides and bottom of the lifters. |
A ring compressor tool is used to contract the rings, allowing the piston to be tapped into the cylinder bore. |
A generous coating of cam lube prevents the camshaft lobes from going flat on engine break-in. |
To properly phase the camshaft with the crankshaft, align the timing chain gears so that the two small dots are next to each other. |
With a hydraulic camshaft, tighten the rocker arm nut until "zero lash," and then tighten the nut one additional turn. |
Install a dial indicator into the lifter bore (this dial indicator is held snugly in the lifter bore by O-rings mounted on the indicator shaft.) Press the dial indicator down into the lifter bore until it contacts the base circle of the camshaft. Then, zero the dial indicator. As the engine is rotated through its firing order, the dial indicator will note how much lift the camshaft is delivering. |
Camshaft degree kits are available from most aftermarket camshaft manufacturers and work with most American-made V8 engines. |
To degree a camshaft, start by using a dial indicator (arrow A) to determine when the No. 1 piston is at Top Dead Center (TDC). Then, install the degree wheel (arrow B) on to the end of the crankshaft. Install the cam degree pointer (arrow C) so that it aligns with the "zero" mark on the degree wheel. |
To degree the cam using the intake centerline method, begin by rotating the engine clockwise until the dial indicator reads about 0.025-inch before maximum camshaft lobe lift. Record this location on the degree wheel (83 degrees, for example--arrow A). Continue rotating the engine in the same direction past maximum lobe lift until the pointer is at the original checkpoint. Mark the degree wheel (140.5 degrees--arrow B). Add the two readings, and divide by two. The result is the intake centerline (111.75 degrees--arrow C). If, according to the camshaft specifications card the intake centerline for the cam is supposed to be 109 degrees, then you must advance the cam 3 degrees. If checking the cam using the 0.050-inch opening-and-closing-points method, rotate the engine clockwise until reaching the 0.050-inch check points, compare the numbers observed on the degree wheel at the proper check points to the numbers listed on the timing card, write down the difference in terms of degrees advanced (early) or retarded (late), and average the results to determine if the cam needs to be advanced or retarded. |
If there is one part of your engine buildup on which to spend a few extra bucks, it&8217s the gaskets. Always buy high-performance gaskets from a reputable manufacturer. |
Traditional piston rings do a good job of sealing a mild engine, but insist on top quality moly rings for performance engine applications. |
A single 600- to 750-cfm four-barrel carburetor usually works best for street-driven engines. |
EFI induction systems work very well in street and race applications, but they cost considerably more than a traditional carb and intake setup. |
A high-volume mechanical fuel pump will most likely be needed if the engine is fitted with a performance camshaft and free-flowing intake system. |
To ensure that the pickup remains securely attached to (and in proper phase with) the oil pump, tack-weld the two together. |
The first 10 minutes of an engine break-in are the most important. Keep engine rpm between 2000-2500 rpm, and continually monitor engine conditions (such as fuel and oil pressure along with spark timing). |
Balancing the engine parts that make up the rotating assembly is highly recommended. A well balanced engine not only delivers smoother operation, but improves bearing life as well. |
At the heart of any potent street machine is a potent engine. Without a powerful mill, your car is all show and no go--which isn't the best reputation to have at the local cruise spot. But, because many cars came equipped from the factory with a lackluster engine, it's up to you to transform your street cruiser into a street bruiser.
Over the years, Car Craft has done countless stories on how to build a gazillion-horsepower engine and how to make your V8 deliver stump-pulling torque. Sometimes, however, these stories are too tech-heavy and/or require mods that are too expensive for the average car crafter. Thus, this tech feature gets back to the basics. Contained within is a wide variety of engine assembly procedures, building tips and recommendations. The advice given is general info and applies to most American-made V8 engines produced by the big auto manufacturers such as Chevrolet, Chrysler/Dodge, Ford, Buick, Olds and Pontiac.
It's important to remember that successfully building your first engine isn't rocket science--it's simply a matter of working carefully and paying close attention to detail. Just remember that if you have an assembly question or are unsure about a torque spec, don't guess, find the correct answer. A variety of sources can provide answers to your engine-building questions. These can be found in places such as the pages of Car Craft magazine, a motor manual (such as Chilton's) for the year/type vehicle you own or by contacting the manufacturer of the part in question. For example, if you're confused about how to adjust the valve lash on your new street/strip camshaft, call the cam company's tech line, and ask the company firsthand. Asking questions first helps to eliminate mistakes, wasted time and wasted money.
The bottom line of building your first engine is to do it right. Remember that if you don't build engines every day for a living, it will probably take you longer to assemble the engine than a race shop. However, there is no trophy given out for the fastest engine builder, so take your time. Allocate one afternoon to building the bottom-end. Then, return another day (with a clear mind and renewed enthusiasm) to install the cam, heads and rocker arms. Breaking up the engine-building process keeps the project (and your entire street machine build-up project) easy and enjoyable. After all, the whole purpose of a musclecar project is to have fun.
For now, though, check out the accompanying photos and captions as well as the A-B-C’s of engine building in the sidebars below.