350 Chevy Rebuild Manual
A well-known expert was asked what he could learn about the “past life” of an engine during disassembly. He responded, “Everything!” Removing each bolt was his equivalent of turning a page in a book titled “A Detailed History of this Engine.” While you may not have the experience to “read” this much detail, the disassembl steps in this chapter (and the inspection steps in Chapter 3) will act asyour “expert” guide. They’ll provide insights and tips that an expert might tell you if he was guiding you through the entire process. To get the most out of this book, take your time, read each of the upcoming steps thoroughly, and think through the procedure before you begin. If this is your first engine rebuild, it’s essential to take the extra time to become familiar with the components you’re removing.
If you already have a good deal of experience with tools and engines, you can move along more quickly. However, regardless of your experience, don’t lose your patience and begin skipping steps; you won’t gain full benefit from the “resident expert” you’re holding in your hands. This Tech Tip is From the Full Book ““. For a comprehensive guide on this entire subject you can visit this link: SHARE THIS ARTICLE: Please feel free to share this post on Facebook / Twitter / Google+ or any automotive Forums or blogs you read. You can use the social sharing buttons to the left, or copy and paste the website link: https://www.chevydiy.com/engine-disassembly-guide-build-chevy-small-block-engines/. Engine Disassembly can tell you a great deal about the “past life” of your engine. Be sure to keep your parts organized during disassembly so you can inspect them further.
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Keep an Organized Workspace One of the best ways to ensure that your rebuilt engine will provide both top performance and long-term reliability is to establish a comfortable workspace and keep it organized. Don’t even attempt this project if you plan on rebuilding your engine while you roll it around on your driveway. You need awell-lit, clean, and relatively dust-free environment. You need a place where you won’t be distracted by telephones, blasting radios, TVs, or a pack of your best friends. You need a clean workbench, a quality engine stand, the proper tools, and most important, you need patience and the unbending will to “do it right.” Rebuilding an engine involves working with hundreds of components. Each part must be properly removed, reconditioned or replaced, and reinstalled.
You can make the job considerably easier and stay more organized by obtaining several plastic storage bins from your local hardware store (warehouse stores such as Menards, The Home Depot, and Lowe’s, etc. Are excellent sources). Use small bins for small-part storage; use large bins to keep exhaust manifolds, oil pans, cylinder heads, and other large components off your shop floor. Plastic bins can easily be cleaned to store reconditioned parts, and they can be stacked to take up less space. Use small bins for small part storage and large bins to keep pans, cylinder heads, and other large components off your shop floor.
Use plastic zipper bags to keep bolts and other components sorted and identified. Use plastic zipper bags to keep bolts and other small components sorted and identified (the freezer bags even have a printed panel where you can label the parts with a felt-tip marker). Many bolts look very much alike but are not interchangeable. If you’re not intimately familiar with your engine’s hardware, organizing fasteners can save you a lot of time and frustration during reassembly. Make sure to use the Work-A-Long Sheet on pages 157–159 (also available for free download at ) when instructed in the upcoming steps. It will not only help you keep track of your engine’s “particulars,” it will become a valuable permanent record of your engine rebuild. Having it neatly and accurately filled out can even add value to your engine in the eyes of a potential buyer.
Finally, many engine accessory brackets, hoses, and wires can become a confusing jumble later on. To avoid this problem, an upcoming step instructs you to take detailed notes and take a couple of photos before and during the disassembly. Don’t limit your picture taking to these specific steps! Take shots at any point during the rebuild that will help maintain an accurate record.
A digital camera is perfect, since there are no processing costs and you can take as many as you need, then file them away on your computer along with any accompanying notes about the photos. Remember, in engine building neatness and organization count, big time!
Tools and Supplies Needed Aside from an organized workspace, plastic bins and bags, and basic hand tools (see Chapter 1, “Before You Begin,” for more information on basic tools), you’ll need a few specialized tools and supplies to properly disassemble an engine. In addition to the standard array of hand tools, engine disassembly requires several specialized tools. Line wrenches (used to remove air-injector and other metal lines), a 3-bolt puller (required to remove the vibration damper), and rod bolt protectors (to prevent the crankshaft from being damaged) are just a few.
Rust Penetrant. To loosen rusted-on exhaust manifold bolts and other stuck fasteners, penetrating lubricants such as WD-40, CRC 5-56, PB Blaster, and others are a big help. These lubricants often make the difference between a broken or rounded-off fastener and successful disassembly. Heavy-Duty Line Wrench. Line wrenches (box end with a slot that allows it to pass over tubing) are required to remove the air-injector lines on exhaust manifolds and the fuel lines from the carb and pump. We recommend Snap-on part RXS18 for the 9/16- inch wrench, or part RXS608 for a complete set.
See Sidebar “Snap-on Tools” on page 10 for more info. Valvetrain Organizer. If you’re reusing the rocker arms, valves, springs, and other valvetrain components, you must keep them in order.
We recommend a plastic organizer tray, like one from Goodson or Eastwood. You can also quickly make one from a cardboard box (punch 16 holes, label it for front and back, then use the valvestems to “skewer” the springs, rockers, etc.). Vibration Damper Puller.
If you try to remove the vibration damper without the right tools, you’ll ruin it. For removal, you’ll need a simple centerbolt puller with three attaching bolts (see Step 32 on page 35). Rod Bolt Protectors. Exposed rod bolts can damage the crank journals during disassembly and reassembly. Short lengths of 3/8-inch rubber hose or plastic protector boots slipped over the bolts are absolutely essential to protect the crankshaft. Goodson and others offer inexpensive protectors.
Rod Removal Tool (optional). A tool that attaches to a rod bolt and guides the rod down the bore when removing the pistons is very helpful. B&B Performance offers an inexpensive Pro model or you can make one yourself (see Step 48 on page 38). Engine Stand and Cherry Picker Hoist.
These items are a bit expensive but absolutely essential—avoid “cheap” models that don’t roll well or barely hold the engine. Seeing your newly assembled engine lying on the floor is no fun! You can rent a cherry picker, but when you consider how long you’ll need an engine stand, it makes sense to buy one of your own (or borrow one from a patient friend). Generous Supply of Clean Rags. Rags can be purchased from home and business supply warehouses. You’ll need about 25 pounds of “lint-free” cotton rags to complete your engine project. Taking photos of your engine (in addition to marking components) before removing it from your car and during the rebuilding process is a great idea.
It will help you maintain an accurate record of your project, plus it can be a big help when you are trying to distinguish one mounting bracket from another. Safety First, Always! Like most jobs, engine disassembly isn’t difficult. All you need are the right tools, patience, and a willingness to learn and think ahead.
If you start rushing the job, you’ll make mistakes that will cost you time and money, and you’ll be sorry. If you ignore this particular facet of engine building, you’ll be more than sorry; you could be seriously injured. There isn’t a professional engine builder that can’t tell you at least one story about an inexperienced “over-enthusiast” losing a finger, toe, or eye, or winding up with other mutilations.
An engine weighs several hundred pounds; you can’t catch it when it falls! A crankshaft propped up in your garage can tip over easily and cut off a toe. Without proper safety glasses or aface shield, metal shavings, solvent, or other debris can wind up in your eye.Without gloves, you can expose yourself to cancer-causing chemicals.
The list is endless. Read the Sidebar, “Shop Safety,” on page 28 before you begin. Think about safety during your entire project.
If you know you don’t have the personality to rebuild an engine using the right tools and in a thoughtful and safe manner, you should not start the job. Instead, take your engine to a qualified enginebuilding shop; you’ll get the job finished faster, maybe even cheaper, and certainly safer. Step-by-Step Engine Disassembly Step-1: Ready to Begin Before we pulled the engine for rebuilding, we noted the different brackets and accessories. Note that this AC bracket goes over the valve cover. If we swap to taller valve covers, chances are that this bracket won’t fit anymore.
Also, the two intake bolts are a little longer to secure this bracket. Step-2: Record Engine Observations ( Documentation Required) This is a 283 out of a 1966 Chevy II. There are many subtle variations in small-block Chevy engines and their accessories. However, there are more similarities than differences and most of the disassembly steps that follow are applicable to all small-blocks. Regardless of whether your engine has all the accessories attached or is partially stripped, your first step should be to use the Work-A-Long Sheet.
Record your knowledge of the engine, including previous operational notes. Also, check off the attached accessories and note any damaged or missing components. This basic information will begin the permanent record of your rebuilding project. Step-3: Record Engine Observations ( Documentation Required) Note the way the alternator bracket mounts to the intake manifold (where the wrench is). If you use an aftermarket intake, be sure there is a mounting hold in the same location.
This is why it is a good idea to take photos and notes before disassembly. Step-4: Before Mounting on Stand ( Safety Step) Several components must be removed (or are easier to remove) before you mount the engine on an engine stand.
To prevent the engine from falling over while you perform the next few steps—and to prepare to lift the engine onto an engine stand—use a “cherry picker” hoist. Attach a lifting chain to the engine. Raise the hoist just enough to take the slack out of the chain. Chain tension will keep the engine upright. Step-5: Remove Crank Centerbolt ( Documentation Required) Locate the large centerbolt holding the damper and front pulley onto the crankshaft. Note: Some engines do not use a centerbolt; indicate its presence or absence on the Work-A-Long Sheet.
If your engine does not have a centerbolt, skip to Step 6. Loosen and remove this bolt with a 1/2-inch-drive breaker bar (or impact wrench).
The crankshaft will probably rotate as you attempt to loosen the bolt. Lock the crankshaft by inserting a pry bar or large screwdriver through one of the flexplate holes or in between the ring gear and starter housing (see Step 4). If there is no flywheel or flexplate on your engine (and you don’t have an impact wrench), leave the centerbolt in place, we’ll remove it later. Step-6: Remove Flywheel or Flexplate Make sure the engine is not resting on the ring gear. Loosen and remove the six bolts that retain the flywheel or flexplate. These bolts are also very tight; use a 1/2-inch-drive socket and a long breaker bar.
Be careful as you remove the flywheel; don’t let it fall on your fingers! Note that the flywheel bolts use star-type lockwashers and have fine threads. Keep them together in your parts bins or bags.
If your engine is equipped with a flywheel and clutch assembly, the pressure plate and clutch disk must be removed first. There will be six bolts holding the clutch disk in place and the bolts should be loosened evenly before being removed. Use care not to drop the pressure plate or clutch disk as you remove it. Step-7: Remove Rear Oil Gallery and Water Jacket Plugs In this step we’ll remove three oil gallery (pipe) plugs and two water jacket core plugs installed in the rear of the block (the large cam plug will be removed later). Note: If you can’t remove any of these core plugs, ask your machine shop to remove them before they clean your block. The gallery plugs: They are extremely tight and often must be drilled and removed with an extractor.
However, they can sometimes be loosened with a special 1/4-inch square-drive pipe-plug socket (Snap-on set 211PPPMY). Never use a 1/4-inch drive ratchet or extension; it will break off and remain jammed in the plug! The core plugs: Remove the two core plugs by first driving them in the water jacket with a large 1/2-inch-drive socket (11⁄16 inches usually works). Then work the plugs to one side, grab them with a Vise-Grip or adjustable pliers, and lever them out. Step-8: Mount Engine on Stand You cannot build a quality engine if you have to roll it around on your garage floor! A heavy-duty engine stand is an essential part of your engine-building project. Use a “cherry picker” to lift the engine into position, then attach the engine to the stand using at least grade-5 bolts that thread into the block no less than 1/2 inch.
Be sure to get the engine secured and put the lock pin in to hold it steady or tighten the lock bolt/setscrew on the stand. Step-9: Drain Oil ( Safety Step) Make sure the engine is securely mounted on the engine stand.
Remove the lift point and/or attaching chains. Before you proceed, consider placing a drip pan on or under your engine stand. If you don’t, engine oil, antifreeze, grease, dirt, rust, and other unpleasant gunk will wind up under foot as you tear your engine apart. Now, drain engine oil from the pan and remove the oil filter. Remember, used engine oil is a toxic waste; keep it off your hands (latex gloves available at most paint stores work nicely) and dispose of it in an environmentally appropriate manner. Step-10: Remove Accessories and Mounting Brackets If your engine is so equipped, begin accessory removal by unbolting the air-conditioning compressor and its mounting bracket.
Next, remove the fan, smog pump, power steering pump, and alternator. Unbolt all remaining mounting brackets located on the front of the engine. Step-11: Remove Distributor/Spark Plugs ( Documentation Required) Distributors are positioned to optimize engine-compartment clearance. Record its general position on your Work-A-Long Sheet before you loosen it. Start by removing all spark plug wires. Then unbolt and remove the distributor hold-down clamp. Remove the distributor by twisting and lifting it by the bottom of the housing.
Note that, as you lift up, the rotor turns. This is due to the helical gear. Don’t apply excessive force to the rotor, cap, or vacuum-advance housing. Finally, remove the spark plugs.
Since the appearance of the insulators can help diagnose some engine malfunctions, you may want to number the spark plugs (masking tape works well) for future reference. While you’re working on top of the engine, strip the intake manifold of the EGR valve, carb, and thermostat housing. Step-12: Apply Penetrant ( Professional Mechanic Tip) Before you attempt to remove any exhaust system bolts and fittings, apply a liberal amount of rust penetrant to each fastener and allow it to soak in for at least 10 minutes. See Sidebar “Removing Stubborn Fasteners” on page 24. If any of the bolts don’t break loose, don’t apply excessive force. Apply more penetrant, and try again.
Step-13: Remove Exhaust Manifolds and Air-Injection Lines Before you remove the exhaust manifolds, mark them with an “L” or “1” (left bank) or an “R” or “2” (right bank). Some stock manifolds are already marked (as ours was). Now bend back any locking tabs on the exhaust manifold bolts, and remove the bolts and manifolds. If your engine has them, remove the spark plug heat shields that are attached to the top edge of the block. If you have AIR tubes to remove from the manifold (if using the same manifolds, leave them in place), soak them in penetrant. Then, use a quality 9/16-inch line wrench, such as this thickheaded Snap-on model (part RXS18), to remove the lines. If an injector tube starts to twist with the nut, STOP!
Apply more penetrant and work the nut back and forth until it turns freely Step-14: Remove Motor Mounts and Starter Some motor mounts/brackets may be left/right interchangeable, while others are not. If you feel there may be any confusion during reassembly, mark each bracket with a tag or stamp.
Remove the front motor mounts and/or mounting brackets from each side of the cylinder block. Next, remove the starter support bracket (if your engine has one). Then remove the two starter attaching bolts. The starter is heavy, so be careful as you remove the final bolt. Step-15: Remove Fuel Pump and Pump Support Plate Remove any fuel lines still attached to the fuel pump. Unscrew the two 3/8-inch pump attaching bolts and remove the fuel pump. Next, remove the two 1/4-inch bolts holding the pump mounting plate to the block.
Use a gasket scraper or screwdriver to pry the mounting plate loose. Finally, slide the fuel-pump pushrod out of the block. Set these components aside in your parts bins. Step-16: Remove All Topside Accessories Remove all remaining accessories from the intake manifold, including the carburetor and choke bi-metal housing. Also, remove the oil pressure sender from the rear of the block. Snap-on and other manufacturers offer special sockets for “idiot light” and gauge-type units. However, a deep socket, open-end wrench, or adjustable pliers will remove most types.
Don’t apply force to the plastic on small senders, or to the “can” on larger sending units. Step-17: Remove Water Pump Remove the water pump by removing the four bolts that secure it to the engine block. When the bolts are removed, you may need a small pry bar or large screwdriver to break the pump loose from the block, but don’t pry against the timing chain cover— you could easily damage it.
Chevrolet used two different length water pumps through the 1960s and early 1970s: a short pump (on the right) and a long pump (on the left). The short pumps were used on engines in Corvettes, Novas, and other engines that were short on space between the pump and the radiator. Be sure to use the same style that you had before, or your brackets and pulleys will be all wrong. Step-18: Remove Valve Covers Remove all remaining components that may still be attached to the valve covers. Then remove the cover bolts and covers.
If you have to pry the covers loose, take your time because excessive force can easily bend them. In about 1986, Chevy changed the retaining arrangement of their valve covers. No longer were the four bolts on the outer edge of the cover and head. The bolts were actually moved to the center of the valve cover (such as the grungy model shown). These were much less prone to oil leaks over time. Step-19: Remove Intake Manifold Remove all Remaining bolts attaching the intake manifold to the cylinder heads.
Most manifolds will come loose after prying with a screwdriver inserted between the manifold and the end-rails of the block. If your manifold seems to be “really stuck,” STOP!
Make sure all the manifold bolts have been removed. When the manifold has been removed, note the heat-riser passage configuration (providing it hasn’t been burned out) of the intake gaskets on your Work-A-Long Sheet for future reference. Step-20: Remove Rocker Arms and Pushrods Remove each of the rocker arms by unscrewing the self-locking nuts. It is recommended that you replace these lock nuts, but try to keep the old ones for your visual inspection. Goodson offers a helpful tray just for valvetrain disassembly. Lift the rocker arm off the stud and pull out the pushrod.
Roll each pushrod on a clean, flat surface to make sure none are bent. Mark or label them and note any damage in your Work-Along Sheet for future reference. Step-21: Remove Head Bolts First, make sure the lock-bolt on the engine stand that prevents block rotation is tight. Use a long, 1/2-inchbreaker bar and a 5/8-inch 6-point socket.
Break all the head bolts loose, then go back with a short-handled ratchet and remove all but two bolts in each head. Leave one bolt near each end of each cylinder head (four bolts). Unscrew these four remaining bolts only two or three turns. Step-22: Remove Cylinder Heads In most cases, the cylinder head will be stuck to the block with sealing compound and corrosion. To coax it loose, insert a breaker bar or pry bar into one of the intake ports and smoothly apply pressure until the head pops up against the two remaining head bolts.
If the head resists prying loose, STOP! Make sure all but two bolts have been removed and the two remaining bolts are loose. After the head is loose, mark it with an “L” or “1” (left bank) or an “R” or “2” (right bank). Now remove the two remaining bolts and lift the head onto your workbench. Use the same technique to remove the other cylinder head. Step-23: Remove and Tag Head Gaskets/Remove Dowel Pins Remove the cylinder head gaskets—they usually remain stuck on the cylinder block. Tag each gasket “LEFT” or “RIGHT” and note its type on your Work-A-Long Sheet.
The cylinder heads and gaskets are located on the block by two dowel pins on each deck surface. Most machine shops remove and replace these pins as a matter of course when machine work is performed. If you have the proper tools, you can remove them now. But don’t drive them into the water jackets. They can become stuck below the deck surface or you may even crack the block and render it useless. The best way to remove them is to first tap them with a hammer and brass drift, and then use a 5/16-inch collet-type puller, such as this tool from Goodson. Step-24: Remove Lifters If you’re considering reusing the camshaft and lifters, each lifter must be reinstalled in the same lifter bore, or you will doom the cam to destruction.
Label each part upon removal or use a disassembly tray like those from Goodson or Crane Cams. Remove each lifter by using a hooked probe to pull it up, then grasp and remove the lifter body with your fingers and/or needle-nose pliers. Some lifters may also be so worn (mushroomed) that they will not slide out of their bores.
If you find any, just pull the lifter up as much as possible, and leave it in the bore. We’ll remove it later. Note the location of any suspect lifters on your Work-A-Long Sheet.
Step-25: Remove Oil Pan and Dipstick Before you rotate the engine on your engine stand, remove the fourteen 1/4-inch and four 5/16-inch pan bolts (the larger bolts are located at each end of the pan). If the pan is stuck to the block (most are), insert a gasket scraper or screwdriver between the block and pan rails, but try not to bend the pan. Gently pry on both sides until the pan comes loose. Also, remove the dipstick and dipstick tube by twisting it back and forth by hand. If it doesn’t come out, insert a 5/16 x 1-inch bolt into the tube and use a pair of adjustable pliers to twist it out. Step-26: Remove Crank Pulley ( Documentation Required) Remove the 3/8-inch bolts that hold the crank pulley to the vibration damper.
Before you toss the bolts into a bin, carefully inspect them, and indicate whether they have fine (NF), like the bolt on the left, or coarse (NC) threads (right) on your Work-A-Long Sheet. Fine threads are used more often, but there is no way to predict what you’ll find. Step-27: Install Damper Puller ( Documentation Required) You must use a 3-bolt puller to remove the vibration damper. This puller is used in a variety of applications so adding one to your toolbox is a good idea. We got ours from Snap-on. Before you begin, check three important things.
First, make sure you’re using the correct puller. Don’t use a puller that grabs the outer ring—you’ll pull the ring right off the damper! Second, make sure the puller draw bolt does not damage threads in the nose of the crankshaft. If you have any doubts, reinstall the crank bolt—without the washer—and allow the draw bolt to push against the head of the crank bolt.
Third, make sure the threads on the three attaching bolts match the threads in the damper and that the bolts have been screwed into the damper at least 3/8 inch. Step-28: Remove Vibration Damper When you’re sure the puller is properly installed, tighten the draw bolt. To prevent the crank from turning, insert a wood handle between the crank and the block. The damper will usually break loose with a “pop.” If the draw bolt gets very tight and the damper won’t budge, STOP! Make sure the draw bolt is properly contacting the crank and that the three attaching boltsare not pulling out of the damper (you should have screwed them in at least 3/8 inch).
If everything looks okay, continue tightening until the damper comes loose. Step-29: Remove Timing Chain Cover Now, remove the 10-1/4-inch timing chain cover bolts—theyoften use separate startype lockwashers.
Place the bolts and lockwashers in your parts bin. If the top dead center (TDC) timing indicator plate is held on with two cover bolts, indicate the attaching bolt locations on your Work-A-Long Sheet. Pry the cover loose by inserting a gasket scraper or screwdriver between the cover and the block; gently pry until the cover comes free. Step-30: Remove Crank Key Remove the vibration-damper locating key in the crank snout by using a 5/16-inch (maximum) non-tapering drift punch. Drive the key toward the front main. As the key moves back in its slot, it will climb out of the crank.
When two-thirds of the key is visible, use pliers to pull it free. Note: If the crank slot is enlarged or the key is loose, the crank may be unusable (more on this in Chapter 3). Step-31: Remove Timing Chain and Sprockets Loosen and remove the three bolts that hold the upper sprocket to the camshaft. The sprocket will usually come off with a slight “tug.” If it’s stuck, gently pry each side of the gear with a screwdriver wedged between the sprocket and the block face. The timing chain will come off with the upper sprocket.
Sometimes the lower sprocket will slide off of the crankshaft with little effort; however, it is often firmly attached. If yours is tight, a gear puller will be needed to remove it. If you don’t have the proper tool, don’t worry about it; your machine shop will remove the lower sprocket for you (usually at no charge) when they inspect or regrind your crank. Step-32: Remove Camshaft ( Professional Mechanic Tip) Removing the camshaft is easier if you install a “handle” like the ones offered by Goodson.
You can also use a long, 3/8-inch NC bolt, or temporarily reinstall the cam sprocket as a handhold. Twist the cam back and forth, as you remove it. Keep the cam centered and prevent it from “falling” against the bearings as it slides out of the block.
Step-33: Rotate Engine in Stand ( Professional Mechanic Tip) Most engine short blocks Contain residual coolant, dirt, rust, and other debris that will fall to your garage floor when you rotate the block upside down. If you don’t have a drip pan under your engine stand, spread rags on the floor to catch as much of the spillage as possible. Turning the engine slowly will also help keep the mess contained. Note: If the pump driveshaft falls out, just set it aside for now. Step-34: Remove Pump Pickup If you are planning to install a new or special oil pump (see Sidebar “Oil Pumps” on page 44), now is a good time to remove the pickup from the pump body. If you will be reusing the old pump, do not remove the pickup and skip to Step 35.
First, make sure that the pickup tube has not been welded or brazed to the pump cover. If it has, remove the weld with a small die grinder before you proceed. Insert a pry bar into the pickup pipe loop as shown. Twist once or twice while pushing the pickup away from the pump cover. The tube should quickly loosen up enough to be removed by hand. Step-35: Remove Oil Pump Remove the single bolt holding the oilpump to the rear main. Wiggle the pump while you’re pulling upward to free the pump from the two dowel pins in the cap.
When loose, continue lifting straight up. In most cases, a plastic attaching sleeve will keep the short pump driveshaft attached to the oil pump. If the shaft separates from the pump, it may fall through the distributor hole and to the floor; this may have happened already when you rotated the engine upside down. Set the pump and driveshaft aside. Step-36: Remove Oil Filter Adapter ( Documentation Required) Remove the two 1/4- or 5/16-inch bolts that hold the oil filter adapter to the block. Note: Your filter adapter may look different from the one pictured here.
When the bolts have been removed, lift the adapter free, note the adapter type on your Work-A-Long Sheet, and set it aside in your parts bin. Step-37: Turning the Crankshaft ( Professional Mechanic Tip) In the following steps, you’ll need to rotate the crankshaft to continue disassembly. You can use a handy crank socket, such as this Snap-on example, which allows you to turn the crank in either direction. In a pinch, you can reinstall the crank centerbolt with a spacer (right photo), then use a standard 5/8-inch socket and breaker bar. Step-38: Number Rod and Main Caps ( Important!) Before you begin bottom-end disassembly, it is essential that you number the rod and main caps. They are not interchangeable, and mixing the caps is a sure road to bearing failure.
Don’t skip this step even if you notice that the caps are already numbered; some engines come with duplicate numbers! You can use center-punch marks.
However, a set of 1/8- or 3/16-inch steel number stamps do a nice job. Regardless of the method you choose, don’t stamp the caps across the parting lines.
Position your numbers or punch marks only on the flat areas adjacent to the parting lines. Stamp both halves of the rods, and to ease assembly, stamp the main caps and the block.
Number the rods 1 through 8 and the mains 1 through 5. Step-39: What to Do About Excessive Cylinder Ridge ( Important!) If your block has a ridge in the bores deeper than about.008 inch, it will catch the rings during assembly. You can use a ridge reamer to remove the ledge and save the pistons, but this may be false economy (especially when you consider that more good blocks are scrapped by the incorrect use of a ridge reamer than any other single mishap).
When a deep ridge has been worn into the bores, the pistons are usually worn out too. So the best solution is simply to drive the pistons out. While the rings or ring grooves may break, the block will not be damaged. To save the pistons, use a top-quality reamer, such as Snap-on’s (part WR30A) or have your machine shop cut the ridge. Step-40: Begin Rod/Piston Removal Begin the rod/piston removal by rotating the crankshaft so that the piston being removed is at BDC; piston is at the bottom of the stroke. Step-41: Loosen Rod Cap Use a long-handled ratchet or breaker bar to loosen the two connecting rod nuts and unscrew them only a few turns. Don’t remove them yet.
Step-42: Protect the Journal ( Important!) It is not essential to use a special tool to remove the rods and pistons. However, it is essential to use some method of protecting the crank journal as the rod bolts slide.
Rebuilders often install short rubber hoses over the bolts. Companies like Goodson sell a set of rod bolt covers that are very durable and handy. (If you use the removal tool described in Step 44, you should install one sleeve and wrap the tool with tape to protect the crank.) Step-43: Don’t Crack the Bore! ( Critical Inspection) Regardless of the method you select to remove the rods and pistons in the upcoming steps, it is absolutely essential that you keep the big end of the rod centered as it moves down the bore. If it drifts up or down, it can catch on the edge of the cylinder bore.
Unfortunately, some engine builders don’t realize the cause of the “hang-up” and deliver several potent hammer blows. This sometimes breaks chunks off the bottom of the cylinder bore, which can convert a perfectly fine block into scrap metal. Don’t let this happen to you! Keep the rod centered as it moves down the bore, and if it gets stuck, make sure you know why before you apply additional force. Step-44: Remove Rods If you do not have a special rod removal tool, use a wooden dowel (an old broom handle works well) that is about 24 inches long. Once the rod is loose from the rod cap, position the dowel on the piston balance pad (see drawing) and drive the piston out. Remember to keep the rod centered.
Be ready to catch the piston before it drops to the floor. You can also make a special tool by welding a nut that will go over the rod bolt to a steel rod. Be sure to wrap the rod with tape to prevent scuffing the crank journal. B&B Performance and other companies sell a professional version.
Step-45: Replace Rod Caps and Nuts Once the rod/piston is removed, replace both bearing shells, put the cap and nuts back on, and set the assembly aside. Keeping the bearings with the rod can help you “read” possible problems (such a rod misalignment, insufficient oiling, bolt stretch, etc.) when we inspect these components in Chapter 3, “Initial Parts Inspection.” Step-46: Remove Remaining Rods/Pistons Now, jump back to Step 40 and repeat the disassembly procedure for the remaining seven rods and pistons. Step-47: Remove Main Bearing Caps Make sure the main caps have been numbered before you remove them from the block (see Step 38).
Using a breaker bar and a 5/8-inch 6-point socket, loosen and remove all ten main-cap bolts. If your engine has 4- bolt main caps, also remove the six side bolts on the three center caps.
The main caps are fitted to the block with a slight interference fit and may require a tap or two with a plastic hammer to free them. Keep the bearing shells with their respective caps. Step-48: Remove One-Piece Rear Main Seal If your small-block was manufactured after 1986 and uses a one-piece rear main seal, perform this step; otherwise skip to Step 49. The crank seal appliance must be removed before the crankshaft can be lifted from the block. First, unscrew the two long and two short bolts that hold the seal support on the rear of the block. Then, pry the appliance loose and slide it straight off the end of the crank.
Step-49: Remove Crankshaft Lift the crank straight up out of the block; you may have to wiggle it slightly (end to end) as you lift to clear the thrust faces on the rear main bearing. Some of the bearing shells may remain stuck to the crank journals as the crank is lifted free. Before they fall off and get mixed up, remove them—along with any bearing shells remaining in the block—and keep them with their respective main caps (Goodson offers parts tags that are great for use in such a situation). Step-50: Remove Two-Piece Rear Main Seal If your engine is a late-model design with a one-piece rear main seal, jump to Step 51. Use a metal probe or a small screwdriver to pry out the rear main seal halves from both the block and rear main cap. Note the seal type on your Work-A-Long Sheet, and then discard the old seal. Also remove the dipstick tube by tapping it from the oil pan deck surface out.
Step-51: Remove Water Jacket Plugs Now, remove the remaining core plugs from the side and front of the block using the same technique described in Step 48. Finally, remove the two water-drain plugs from each side of the block with a 9/16-inch 6-point socket and a 1/2-inch breaker bar. Don’t use a 12-point socket on these plugs; they are usually very tight. Step-52: Remove Remaining Plugs Rotate the engine right-side up. Remove the 1/8- inch pipe plug in the oil pressure access at the front of the block.
Next, remove the two 1/4-inch oil gallery plugs at the back of the block using the techniques described in Step 48. A final cup-type plug is located in the oil passage just under the rear main cap. Although most engines are rebuilt without removing this plug, you cannot thoroughly clean the passage with it in place. To remove the plug, insert a 1/4-inch-diameter, 24-inch-long steel rod (found at most hardware stores) into the oil-pressure access at the rear of the block. A few taps with the hammer will drive the plug out. Also, if you have any stuck lifters, that you could not remove earlier, now is the time to drive them down and into the block. Step-53: Cylinder Head Disassembly Many of the steps involved in rebuilding cylinder heads are well outside the capabilities of most home shops.
For an overview of these procedures, refer to Chapter 5, “At the Machine Shop.” Because of these technical requirements, you may choose to take your cylinder heads to a qualified shop and leave the disassembly and reconditioning to them. On the other hand, if you have a valvespring compressor and you’d like to disassemble the heads yourself, proceed with Step 54. Step-54: Compressing the Valvespring The valve locks often become firmly stuck in the spring retainers. To free them, position the head with the chambers facing down on a soft wooden surface. Use a brass hammer and socket to strike each retainer several times (with moderate force) until you “feel” it break loose. Reposition the head with the intake ports facing down and try your valvespring compressor.
If the retainer won’t budge, give it a few more hammer raps. Step-55: Remove Locks and Springs When the spring is compressed and the valvelocks are exposed (adjust your spring compressor to almost fully compress the valvespring), remove the locks with a probe or magnetic tool (this one is from Goodson).
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Now release the spring compressor. Sometimes the rubber O-ring on the valvestem becomes so hard that it will not let the retainer slide off.
You may have to pry the retainer loose with a screwdriver. Step-56: Remove Keeper Burrs ( Important!) In some cases, the valvelock grooves in the valvestem can develop a raised “burr” that will prevent the valve from sliding through the guide. Do not drive the valve out with a punch. Use a small, fine file—positioned flat against the valvestem—to remove the raised lip around the lock grooves. Rotate the valve head while you gently file the stem. When all of the raised edge is removed, the valve will easily slide out of the cylinder head.
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Step-57: Keep Parts Organized ( Important!) If you Are planning to simply replace parts or perform other limited reconditioning work (to save money or if the heads are in very good condition), you should keep everything together. This plastic organizer from Goodson does the job in style. Step-58: Engine Disassembly Complete This completes disassembly. In Chapter 3, we’ll take a closer look at the piston assemblies (the rings, pistons, rods, and rod bearings), the cylinder heads, the block, crank, and other components before they are sent to the machine shop. It is in this and other upcoming chapters that you’ll determine what parts can be reused and/or rebuilt. Upcoming chapters will also discuss component selection and cleaning, and will go through a pre-assembly fitting session to make sure all parts work together efficiently and reliably. Written by Larry Schrieb and Posted with Permission of CarTechBooks.