LS Engine DIY

Do It Yourself LS Engines

Gen III (3) LS 500+ Horsepower NA Street-Racer Buildup

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If there is any doubt remaining about the power potential of the Gen III LS1/LS6 engine architecture, the following real-world engine buildup should clear that up. Simply put, there is no other production 5.7-liter small-block pushrod V-8 engine design in the world that is as easy to build and responds to a set of race-inspired CNC-port cylinder heads and an aggressive camshaft with a streetable 500+ hp.

 

This Tech Tip is From the Full Book, HOW TO BUILD HIGH-PERFORMANCE CHEVY LS1/LS6 V-8S. For a comprehensive guide on this entire subject you can visit this link:
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Now, this engine will have the hardcore lopey idle and need for premium gasoline that any high-performance, naturally aspirated engine would exhibit, but the powerband and peak numbers will more than justify those realities. This chapter will show you the details required to assemble any Gen III V-8, while presenting a standard combination of parts to create 500 hp.

 

Power Parts

The Gen III V-8 engine upgrade components used here were originally developed from GM Powertrain components by the people at GM Racing. The aftermarket industry then refined this package. This engine is being built by Wheel to Wheel Powertrain (W2W), in Warren, Michigan, for use in a road racing Corvette, but it isn’t much different from the street Gen III V-8s they build every day for hot rod daily drivers. The big difference between their street engines is this one has some aftermarket components in the short block, like a forged crank, billet rods, forged aluminum pistons, and other performance pieces.

Many of the 500+ hp street engines W2W builds don’t have anything changed in the short block — a testament to the Gen III V-8 capability. But the aftermarket additions are shown because it’s a good thing to show how aftermarket components are integrated into the Gen III in case more than 530 hp is desired — as that seems to be the limit for some factory components like the pistons and rods. In this chapter, you’ll see the machine work and finesse needed to assemble a 500+ hp Gen III V-8 engine. Then, whether you choose to build this engine with the stock short-block or add even more aftermarket performance components, you’ll have enough info to understand what it will take to get the engine together.

While W2W does have some tricks and refined processes they perform to extract the maximum performance and durability from these packages, almost all of the processes shown here can be repeated by anyone with similar results. And W2W is quick to give this engine design its due — they acknowledge the ease with which power is unleashed from the LS1/LS6 Gen III V-8 as a direct result of the excellent engineering by the people at General Motors Powertrain and Racing.

 

External Pump Oiling System

As you will see, the engine built in this chapter is assembled with a dry sump oiling system that uses a two-stage external oil pump as the scavenge pump with the factory oil pump on the pressure stage to make sure oil flows to the engine in high-G cornering situations. This system is being used because the vehicle and driver this engine will service run hard through corners and experience high G-loads for sustained periods. If you are building an engine for a more street oriented application, you can save the money this system costs and use the factory wet-sump oiling system instead.

The term “dry sump” comes from the fact that the oil is not stored in the bottom of the engine anymore. There is an external oil sump holds more oil than would normally be used in a production oil pan, which allows the oil to cool and let the air percolate out of it. Storing the oil somewhere other than the bottom of the engine allows the oil pan to be much more shallow, which allows the engine to be mounted lower in the vehicle. Since the oil is not allowed to sit in the bottom of the engine, the chances of the oil roping around the crank, eating horsepower, and getting more air whipped into it, are minimized.

The choice between the dry-sump and wet-sump system usually is driven by how oil needs to be drawn out of the engine, not how oil is pumped into it. The two-stage external oil pump is actually two oil pumps that run off a common shaft. Each pump, or stage, draws oil from a different area of the oil pan. Many drysump systems use a three-stage pump, with one of the stages pressurizing the oil and the other stages sucking it out of the engine. The system used here is designed this way because of the rules in a road racing series mandating that the factory oil pump be used in the oiling system.

Dry-sump systems are mostly used in engines that will go in vehicles that can achieve high lateral grip for extended periods, like a road race car. They are expensive, but are good insurance the engine won’t starve for oil at the end of a long cornering experience, which would obviously result in a more expensive problem. Wet-sump oiling systems don’t have the same amount of oil and control of the oil in the oil pan as the dry sump systems, which can lead to starvation of oil to the oil pump.

W2W has built 500+ hp Gen III V-8 engines with both the dry and the wet sump oiling system for the street and have never had a problem with durability in either case. It does depend on how you drive the vehicle, but in general, if you do not drive multiple race laps with the car on a road race track, the wet sump system should be acceptable.

 

Simple Performance

W2W uses either the LS1 or LS6 engine as their starting point to build this 500+ hp engine. The only real difference between the LS1 and LS6 engine short blocks is the pre-’01 LS1s didn’t have ascast “windows” between the mains in the bottom end of the engine block for highrpm air and oil-vapor flow. If you plan on spending sustained periods of time at high rpm, the later LS6 block (casting number 12561168) is the correct choice as it has better crankcase oil control.

Beyond the block, since the cylinder heads, camshaft, and intake are being swapped out, it doesn’t matter whether you start with an LS1 or LS6 engine or even a 4.8-, 5.3-, or 6.0-liter iron-block truck engine. Most performance enthusiasts prefer the aluminum block LS1/LS6 engine for the weight savings, but the iron-block engines are similar in design and cost less if weight is not that big of an issue for you. Obviously, the smaller-displacement engines will make less overall power, while the 6.0-liter should make just a little bit more power than the 5.7- liter LS1 engines.

The CNC cylinder heads W2W prefers to use are the GM Performance Parts CNC heads. There are two versions, the more aggressive 11.2:1 compression head (PN 88958622), or the just released 10.5:1 compression heads (PN 88958665). Ron Sperry, the GM Racing engineer that originally designed much of the Gen III V-8 cylinder head ports and chambers, did the development of these CNC-ported heads.

The 8622 heads have a small 62-cc combustion chamber, while the 8665 heads have close to the production 65-cc chamber. Both heads have 250-cc intake ports, 85-cc exhaust ports, and can support north of 500 hp. They come with the impressive LS6 factory valvetrain — hollow-stem stainless-steel valves (sodiumand potassium-filled on the exhaust side), chromium-silicon (Cr-Si) ovate beehive valvesprings, and other equipment.

The milling of both of these heads means they will probably need different length pushrods to maintain good alignment of the pushrod tip and rocker cup. The 8622 heads often end up with a 7.325-inch pushrod, while the 8665 heads mostly run with the factory-length pushrods. Maximum lift is considered to be 0.570 inch.

There are plenty of CNC cylinder heads available, but W2W’s feeling is the GM people, especially Sperry, probably know best how to maximize performance with CNC-ported heads. After all, they understood what they had to start out with, and had a tremendous amount of technology available to make the improvements.

Besides these heads, this engine is loaded with aftermarket components for increased durability and performance. The forged steel Lunati crankshaft used here is the stock 3.622-inch stroke of race rules, but the cranks can be ordered with up to a 4.125-inch stroke to increase displacement. If a longer stroke is desired, sometimes the block will need to be clearanced for the big end of the rods to clear the bottom ends of the bores and bottom of the engine block. This usually depends on what brand rods you are using — often there is no clearancing required. Also, a groove will need to be machined on the number-8 piston so it will clear the reluctor wheel on the crank.

A nice touch is that the Lunati crank comes with the GM factory 24x crank trigger reluctor ring installed on it, so the factory crank trigger will work without any modifications.

The 3.897-inch diameter (for a 3.901-in bore) forged aluminum JE pistons used here offer advantages in durability and performance production over the factory eutectic cast-aluminum pistons for a 500-hp engine. They are machined to accept a standard hotrod/racing ring package of a 1.5-mm top, 1.5-mm second, and 3-mm oil spacer/separator ring pack.

The production eutectic cast-aluminum pistons are a low cost alternative to the forged aluminum pistons, which is good if you are building tens of thousands of 400-hp mass-production engines. But, since this is a performance engine and saving a few pennies on each piston isn’t the main concern, forged pistons are a good choice. This isn’t to say cast pistons won’t work on the street, but the owner of this engine was willing to spend the money for a little increase in insurance against a failure.

The reasoning against eutectic castaluminum pistons for peak performance applications is based on experience. These pistons are less forgiving to the pounding of detonation and preignition, and have a tendency to break into pieces instead of just lifting a ring land or melting slightly, as forged pistons usually do when stressed beyond their limit. While many enthusiasts think they aren’t going to come close to causing one of these issues, we all know that high-performance engines live in danger.

Peak horsepower is made with the air/fuel ratio and ignition timing set where the engine is just on the edge of detonation, what many hot-rodders call the “rattle of power.” Near this fine line, a forged piston offers a considerable safety net, which is why their cost should be considered the price of entry when building a powerful engine.

W2W likes to use JE or CP pistons in these engines. If you are going to use the stock rod and crank, W2W recommends JE PN 194884. These pistons are set up to work with the stock LS1 6.094-inch rod length, 0.944-inch piston pin, and 3.625- inch LS1 crank. If you are going to use an aftermarket rod and piston, W2W recommends the JE PN 194883 pistons so they can use a 6-1/8-inch connecting rod and a 0.927-inch floating piston pin with locks.

 

Controlling it All

As with any Gen III V-8, the engine is run by either the production powertrain control module (PCM) controller, or by an aftermarket electronic controller. A F.A.S.T. electronic controller runs the engine being built in this chapter with a program developed by W2W. At the time this engine was built, the F.A.S.T. controller was not yet reading the 24x crank trigger, though it will be able to by the time this book is published. Because of this, W2W installed one of their 4-point magnetic pickup systems. The pickup sticks through the bellhousing on the oil filter side of the block to read four magnets embedded in the W2W-modified flywheel.

By the time this book comes to market, pretty much all the aftermarket controller companies should be able to plug in to the factory crank trigger senders to run the engines, but right now only a few can run off the factory crank triggers.

Take a look at the last chapter in this book for more details on how to alter the calibration on the Gen III factory controller. Also discussed in Chapter 10 is how the aftermarket is modifying the factory calibrations to work with performance components and how to get a Gen III running on an aftermarket controller.

 

Every Last Detail

Simply put, this chapter, and complimenting info throughout this book, thoroughly documents the procedure needed to build a 500+ hp Gen III V-8 street engine. By that, we mean the information presented elsewhere in this book is not repeated in this chapter, but referenced here for you to find. This way, space is not wasted covering information that is already shown. Some examples of this are the processes of degreeing a camshaft, aligning the stressed-member oil pan with front and rear covers, and installing an intake manifold. From there, attaining the pleasant roar of a small-block Chevy Gen III V-8 coming from under your ride’s hood is up to you.

 

The process of building a legitimate 500+ horsepower 5.7-liter LS1 street engine is fully documented here for you to recreate. If you’re going to be running aftermarket components, you’ll need some professional help with some of the machine work, but other than that, just swapping in these components will net you a 500+ hp V- 8 engine — check out the dyno figures at the end to see for yourself!

The process of building a legitimate 500+ horsepower 5.7-liter LS1 street engine is fully documented here for you to recreate. If you’re going to be running aftermarket components, you’ll need some professional help with some of the machine work, but other than that, just swapping in these components will net you a 500+ hp V- 8 engine — check out the dyno figures at the end to see for yourself!

 

Installing high-performance parts is good insurance when building a performance engine. Many enthusiasts choose to install aftermarket components like these — a Lunati forged crank, Oliver billet steel rods, and JE forged aluminum pistons for increased durability. If you don’t plan on doing any long, sweeping corners, you don’t need the dry sump, multistage oil pump either — the stock oiling system will work beyond 500 hp.

Installing high-performance parts is good insurance when building a performance engine. Many enthusiasts choose to install aftermarket components like these — a Lunati forged crank, Oliver billet steel rods, and JE forged aluminum pistons for increased durability. If you don’t plan on doing any long, sweeping corners, you don’t need the dry sump, multistage oil pump either — the stock oiling system will work beyond 500 hp.

 

Block Prep

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If you plan on running forged pistons and moly-faced rings, the bores need to be honed to establish the proper bore surface for these components. The bores will be enlarged only about 0.0005 inch from the honing, so their diameters will stay essentially 99 mm. A set of 3.897-inch forged JE pistons was ordered to fit this bore size and they’re measured and matched to each of the eight cylinders. The honing improves the concentricity of the bores because it is done with a deck plate installed. The deck plate simulates the head being torqued to the block, so the resulting bore will be more concentric (round) when the engine is assembled — allowing the piston and rings to seal better for more power and better oil control. When GM hones the blocks at the factory, they do so without using a torque plate.

If you plan on running forged pistons and moly-faced rings, the bores need to be honed to establish the proper bore surface for these components. The bores will be enlarged only about 0.0005 inch from the honing, so their diameters will stay essentially 99 mm. A set of 3.897-inch forged JE pistons was ordered to fit this bore size and they’re measured and matched to each of the eight cylinders. The honing improves the concentricity of the bores because it is done with a deck plate installed. The deck plate simulates the head being torqued to the block, so the resulting bore will be more concentric (round) when the engine is assembled — allowing the piston and rings to seal better for more power and better oil control. When GM hones the blocks at the factory, they do so without using a torque plate.

 

2. Boring and honing are machining processes performed to get the cylinder bores to the proper diameter and concentric over the length of the bore with the required finish. The boring process involves spinning a cutting tool inside the bore, while the honing process consists of rubbing stones on the surface to end up with the proper setup for making power. As an example of the complexity of these processes, the honing process requires a seemingly endless amount of stones and oils to rub on the bore surface, and the honing tool has a gauge that shows the drag on the stones as they’re spun and reciprocated up and down the bore. A good hone operator will know what combo of stones, oil, and drag to use for a certain type of engine (blown or normally aspirated), piston (cast or forged aluminum), and ring package (moly-filled, chrome, mild-steel, etc.). Sound involved? Good, because it is — find someone good at this and let them do it for you.

2. Boring and honing are machining processes performed to get the cylinder bores to the proper diameter and concentric over the length of the bore with the required finish. The boring process involves spinning a cutting tool inside the bore, while the honing process consists of rubbing stones on the surface to end up with the proper setup for making power. As an example of the complexity of these processes, the honing process requires a seemingly endless amount of stones and oils to rub on the bore surface, and the honing tool has a gauge that shows the drag on the stones as they’re spun and reciprocated up and down the bore. A good hone operator will know what combo of stones, oil, and drag to use for a certain type of engine (blown or normally aspirated), piston (cast or forged aluminum), and ring package (moly-filled, chrome, mild-steel, etc.). Sound involved? Good, because it is — find someone good at this and let them do it for you.

 

Ring Fitting

 

1. Setting the proper ring gaps is critical if you want your engine to make good power, last a long time, and not burn excessive amounts of oil. The following is a complete breakdown of the process of setting ring gaps for a traditional ring pack. The first step is to set the first or second ring gently in the bore it will be used in.

1. Setting the proper ring gaps is critical if you want your engine to make good power, last a long time, and not burn excessive amounts of oil. The following is a complete breakdown of the process of setting ring gaps for a traditional ring pack. The first step is to set the first or second ring gently in the bore it will be used in.

 

2. Then use a ring depth-setting tool, like this one shown here, to set the ring in the bore perpendicular to the bore centerline at a specific depth in the bore. This depth is usually 1 inch below the deck height.

2. Then use a ring depth-setting tool, like this one shown here, to set the ring in the bore perpendicular to the bore centerline at a specific depth in the bore. This depth is usually 1 inch below the deck height.

 

3. The problem with the ring depthsetting tool is that you can’t see whether the ring is seated up against the tool. For this reason, you want to…

3. The problem with the ring depthsetting tool is that you can’t see whether the ring is seated up against the tool. For this reason, you want to…

 

4. … reach up under the ring depthsetting tool to pull the ring firmly up against the bottom of the ring depth tool.

4. … reach up under the ring depthsetting tool to pull the ring firmly up against the bottom of the ring depth tool.

 

5. With the ring set in the proper location, pull the depth tool out of the way and measure the gap with a variety of feeler gauges. The thickest feeler gauge that fits in the gap between the ends of the ring is its gap. Write this number down and keep the rings organized so you know what rings have what gaps. Now it is time to file the ends to increase the gap, if required.

5. With the ring set in the proper location, pull the depth tool out of the way and measure the gap with a variety of feeler gauges. The thickest feeler gauge that fits in the gap between the ends of the ring is its gap. Write this number down and keep the rings organized so you know what rings have what gaps. Now it is time to file the ends to increase the gap, if required.

 

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6. A ring filing machine is a small grinding apparatus that requires care and knowledge to use correctly. You want to file the ring gap to the proper width and make sure the ground edge is perpendicular to the ends of the ring. With the wheel static, mate the face of the ring gap up with the grinding wheel. Clamp the ring in this location and pull the ring end back before starting the grinding wheel motor. Start the electric motor and grind off a small amount of ring. Then remove the ring from the machine and install it in the cylinder to be remeasured. Repeat as needed to achieve the proper ring gap on all of the top and second rings. Tape the ring sets together and mark with the bore number as you progress.

6. A ring filing machine is a small grinding apparatus that requires care and knowledge to use correctly. You want to file the ring gap to the proper width and make sure the ground edge is perpendicular to the ends of the ring. With the wheel static, mate the face of the ring gap up with the grinding wheel. Clamp the ring in this location and pull the ring end back before starting the grinding wheel motor. Start the electric motor and grind off a small amount of ring. Then remove the ring from the machine and install it in the cylinder to be remeasured. Repeat as needed to achieve the proper ring gap on all of the top and second rings. Tape the ring sets together and mark with the bore number as you progress.


 
LSB

 

Bearing Clearance

 

1. You’ll need to remove the rod cap in preparation for creating the proper rod bearing clearances. Begin this process by placing the rod in an aluminum rod clamp and using a large breaker bar to loosen the rod bolts. Don’t use a standard bench vise for this job as any nick or ding in the rods caused by the vise will become a stress riser that could cause the rod to fail prematurely. The rod clamp is made of soft aluminum and has a wide, flat surface to spread the clamping load out over the rod surface without damaging it.

1. You’ll need to remove the rod cap in preparation for creating the proper rod bearing clearances. Begin this process by placing the rod in an aluminum rod clamp and using a large breaker bar to loosen the rod bolts. Don’t use a standard bench vise for this job as any nick or ding in the rods caused by the vise will become a stress riser that could cause the rod to fail prematurely. The rod clamp is made of soft aluminum and has a wide, flat surface to spread the clamping load out over the rod surface without damaging it.

 

2. With the rod bolts loosened, flip the rod around in the rod clamp, reclamp it on the cap portion of the rod, and then slightly wiggle it up and down until the rod cap comes loose.

2. With the rod bolts loosened, flip the rod around in the rod clamp, reclamp it on the cap portion of the rod, and then slightly wiggle it up and down until the rod cap comes loose.

 

3. You should establish the rod bearing clearances and then the main bearing clearances at this point. See Chapter 9 to see how main bearing clearances are established. For the rods, use the standard cut-and-paste manner of measuring bearings in the rods against the diameters of the crank journals to create the appropriate clearance between bearing and journal.

3. You should establish the rod bearing clearances and then the main bearing clearances at this point. See Chapter 9 to see how main bearing clearances are established. For the rods, use the standard cut-and-paste manner of measuring bearings in the rods against the diameters of the crank journals to create the appropriate clearance between bearing and journal.

 

4. Achieve a 0.0025-inch rod bearing clearance by assembling the rods with the bearings crushed in the big end of the rod. Using a micrometer, or in this case, a hone measureing tool, measure and record the smallest inside diameter (ID) of the rods. Then, measure and record the outside diameter (OD) of the crankshaft journal. You can set the clearances for each rod bearing by changing to different ID rod bearing halves. Side clearance should be 0.012 to 0.018 inch as measured with a feeler gauge with the rods installed on the crank.

4. Achieve a 0.0025-inch rod bearing clearance by assembling the rods with the bearings crushed in the big end of the rod. Using a micrometer, or in this case, a hone measureing tool, measure and record the smallest inside diameter (ID) of the rods. Then, measure and record the outside diameter (OD) of the crankshaft journal. You can set the clearances for each rod bearing by changing to different ID rod bearing halves. Side clearance should be 0.012 to 0.018 inch as measured with a feeler gauge with the rods installed on the crank.

 

Hanging the Pistons on the Rods

 

1. The pistons for this project are forged aluminum, with spiral locks and floating pins. Hanging them on the connecting rods is a little different from hanging the production pressedon pistons and pins. The floating pins are better for performance as they eliminate the fear that the production piston/pin “press” is not robust enough to keep the pins in place during high-rpm, high-power situations. These are key internal components, so it’s critical that the assembly area and tools are clean and that the parts are all present before you start.

1. The pistons for this project are forged aluminum, with spiral locks and floating pins. Hanging them on the connecting rods is a little different from hanging the production pressedon pistons and pins. The floating pins are better for performance as they eliminate the fear that the production piston/pin “press” is not robust enough to keep the pins in place during high-rpm, high-power situations. These are key internal components, so it’s critical that the assembly area and tools are clean and that the parts are all present before you start.

 

2. The first step is to install the set of spiral locks on one side of the piston. Spiral locks are tricky to work with at first, but they are a basic component, so you’ll get it down. Essentially, get one end of the lock in the piston groove, hold it in place with one finger, and then work it around with your other fingers until it’s all in the groove. Install the second spiral lock in the same groove in the same manner (use two for insurance).

2. The first step is to install the set of spiral locks on one side of the piston. Spiral locks are tricky to work with at first, but they are a basic component, so you’ll get it down. Essentially, get one end of the lock in the piston groove, hold it in place with one finger, and then work it around with your other fingers until it’s all in the groove. Install the second spiral lock in the same groove in the same manner (use two for insurance).

 

3. W2W recommends brushing on a light — and they mean light — coat of straight 30-weight oil on the piston pin boss. They also brush a very light coat of 30-weight oil on the pin and the pin bore in the rod just before installation. Essentially, their feeling is that this area usually has very little oil on it when the engine is running, so why glop a bunch on and encourage the oil to solidify or worse at startup?

3. W2W recommends brushing on a light — and they mean light — coat of straight 30-weight oil on the piston pin boss. They also brush a very light coat of 30-weight oil on the pin and the pin bore in the rod just before installation. Essentially, their feeling is that this area usually has very little oil on it when the engine is running, so why glop a bunch on and encourage the oil to solidify or worse at startup?

 

4. With all the components lubed up, it’s time to start assembling the rods and pistons. It’s a good idea to assemble the piston/rod combo, install the rings on the pistons, and install the piston/rod combo in the engine in one sitting. This will minimize the amount of dust and dirt attracted by the oiled-up components. You don’t want too much gunk shoved in the engine during the assembly.

4. With all the components lubed up, it’s time to start assembling the rods and pistons. It’s a good idea to assemble the piston/rod combo, install the rings on the pistons, and install the piston/rod combo in the engine in one sitting. This will minimize the amount of dust and dirt attracted by the oiled-up components. You don’t want too much gunk shoved in the engine during the assembly.

 

5. With the pin pushed through the piston, install the other pair of spiral locks in the piston to lock the floating piston pin in the piston. Make sure you have matched the piston and rod for each bore (remember, the rings are set for a certain bore and the rod bearings are set for a certain journal).

5. With the pin pushed through the piston, install the other pair of spiral locks in the piston to lock the floating piston pin in the piston. Make sure you have matched the piston and rod for each bore (remember, the rings are set for a certain bore and the rod bearings are set for a certain journal).

 

6. This is what the spiral locks look like up close. Notice the angle cut on one end. This is so the locks can be pried out of the lock groove on the piston.

6. This is what the spiral locks look like up close. Notice the angle cut on one end. This is so the locks can be pried out of the lock groove on the piston.

 

7. Just in case you need to remove a spiral lock from a piston, here’s how it’s done. First, you’ll need a small 90- degree pick or screwdriver to get up under the lock in the groove. Pry the tapered end of the lock up and over the groove edge and continue to work the lock out with another small screwdriver. Getting started is the hardest part; after that, it usually just takes some simple prying.

7. Just in case you need to remove a spiral lock from a piston, here’s how it’s done. First, you’ll need a small 90- degree pick or screwdriver to get up under the lock in the groove. Pry the tapered end of the lock up and over the groove edge and continue to work the lock out with another small screwdriver. Getting started is the hardest part; after that, it usually just takes some simple prying.

 

Installing Rings on Pistons

 

1. Now that the pistons are on the rods, it’s time to get the gapped rings installed on the pistons. Like the rod/piston assembly process, you should have clean tools and a clean area to work in.

1. Now that the pistons are on the rods, it’s time to get the gapped rings installed on the pistons. Like the rod/piston assembly process, you should have clean tools and a clean area to work in.

 

2. Most rings are identified by a dot on the face and the location of the taper on the inner edge of the ring in relation to the dot. The rings are usually installed with the dot facing up. To identify which are the top rings, start with the dot facing up and look to the inside edges of the ring. In general, the top rings will have the taper on the upper, inner edge, while the second rings will have the taper on the lower, inner edge.

2. Most rings are identified by a dot on the face and the location of the taper on the inner edge of the ring in relation to the dot. The rings are usually installed with the dot facing up. To identify which are the top rings, start with the dot facing up and look to the inside edges of the ring. In general, the top rings will have the taper on the upper, inner edge, while the second rings will have the taper on the lower, inner edge.

 

3. Some engine builders like to use a ring spreader to install the rings, while some think it’s acceptable to work the ring onto the piston by hand. This W2W engine builder chose to install the rings by putting one end of the ring in the ring land and working it onto the piston with his hands. Before doing this, wipe the rings with a light coat of 30-weight oil. As a note, the reason some engine builders prefer to use the spreader instead of the hand method is that they feel the spreader minimizes the chance of putting a “twist” in the ring that hurts the ring’s ability to seat flat in the ring land. You decide.

3. Some engine builders like to use a ring spreader to install the rings, while some think it’s acceptable to work the ring onto the piston by hand. This W2W engine builder chose to install the rings by putting one end of the ring in the ring land and working it onto the piston with his hands. Before doing this, wipe the rings with a light coat of 30-weight oil. As a note, the reason some engine builders prefer to use the spreader instead of the hand method is that they feel the spreader minimizes the chance of putting a “twist” in the ring that hurts the ring’s ability to seat flat in the ring land. You decide.

 

4. Most engine assemblers have a ring gap clocking method that they follow, and W2W is no different. While the rings can move around in the ring lands once the engine is running, the startup positions are considered very important. In this case, the rings are clocked as such on the piston from recommendations in the GM Powerbook. As a note, GM Powertrain does not clock the top two rings in the production build of the Gen III, but the oil ring spacers and spreader gaps are clocked to themselves and to the top and second ring. For more on this, see Chapter 2.

4. Most engine assemblers have a ring gap clocking method that they follow, and W2W is no different. While the rings can move around in the ring lands once the engine is running, the startup positions are considered very important. In this case, the rings are clocked as such on the piston from recommendations in the GM Powerbook. As a note, GM Powertrain does not clock the top two rings in the production build of the Gen III, but the oil ring spacers and spreader gaps are clocked to themselves and to the top and second ring. For more on this, see Chapter 2.

 

Installing the Crank in the Block

 

1. With the clearances determined earlier in the buildup, now is the time to install the crank. To start, the upper half of the main bearing shells are wiped down with a light skim of 30-weight oil on the outer surface and pushed into the appropriate place in the block. Before this step, all of these bearings were cleaned in the solvent tank to insure no packing materials or other debris ended up in the engine — you should wash all new components in solvent.

1. With the clearances determined earlier in the buildup, now is the time to install the crank. To start, the upper half of the main bearing shells are wiped down with a light skim of 30-weight oil on the outer surface and pushed into the appropriate place in the block. Before this step, all of these bearings were cleaned in the solvent tank to insure no packing materials or other debris ended up in the engine — you should wash all new components in solvent.

 

2. Once you place the crankshaft in the engine, it’s a good idea to spin it over to make sure it clears the engine block and there is no binding. If there are no issues, you can continue with the installation process. If there is interference, stop and check the bearing clearances again. Issues usually have to do with the overall crank diameter and the thrust bearing clearance.

2. Once you place the crankshaft in the engine, it’s a good idea to spin it over to make sure it clears the engine block and there is no binding. If there are no issues, you can continue with the installation process. If there is interference, stop and check the bearing clearances again. Issues usually have to do with the overall crank diameter and the thrust bearing clearance.

 

3. Remember to give the bottom bearing shells a light coat of Pro Lube engine assembly lube before you snap them into the main caps.

3. Remember to give the bottom bearing shells a light coat of Pro Lube engine assembly lube before you snap them into the main caps.

 

4. Drop the main caps in place on the engine block. Notice how the deepskirted Gen III V-8 engine block allows for main caps with four vertical bolts and two horizontal bolts. The factory main caps are powdered metal and can handle up to 550 hp, while aftermarket billet steel main caps can handle over 650 hp. The factory caps don’t have dowels, but many of the aftermarket caps do. The factory caps nest into the sides of the block for an almost swedge-like fit.

4. Drop the main caps in place on the engine block. Notice how the deepskirted Gen III V-8 engine block allows for main caps with four vertical bolts and two horizontal bolts. The factory main caps are powdered metal and can handle up to 550 hp, while aftermarket billet steel main caps can handle over 650 hp. The factory caps don’t have dowels, but many of the aftermarket caps do. The factory caps nest into the sides of the block for an almost swedge-like fit.

 

5. As was discussed earlier, the Gen III V-8 engine uses bolt stretch to create the appropriate fastener-clamping load on the critical components. Because of this, it’s important to add a light skim of grease where the bolt head seats on the main and/or under the head of the bolts.

5. As was discussed earlier, the Gen III V-8 engine uses bolt stretch to create the appropriate fastener-clamping load on the critical components. Because of this, it’s important to add a light skim of grease where the bolt head seats on the main and/or under the head of the bolts.

 

6. Begin the torquing procedure by hand-tightening all the fasteners down in the torquing sequence recommended by General Motors. Refer to the torquing chart shown above.

6. Begin the torquing procedure by hand-tightening all the fasteners down in the torquing sequence recommended by General Motors. Refer to the torquing chart shown above.

 

7. This illustration details the GM recommended main-cap torquing sequence. Once all the caps are fully nested in the block, start by torquing fasteners 1-20 to 22 ft-lbs, and then loosen them. Push the crank forward to full thrust. Re-torque fasteners 1- 10 to 15 ft-lbs, then add 80 degrees of torque angle. Then, torque fasteners 11-20 to 15 ft-lbs and loosen them to hand tight. Re-torque them to 15 ft-lbs and add 53 degrees of torque angle. Now torque fasteners 21-30 to 18 ft-lbs, doing them as pairs per each main cap. The side bolts can be reused but need to be cleaned and have a small bead of sealer put under the head of the bolt because they thread into the crankcase.

7. This illustration details the GM recommended main-cap torquing sequence. Once all the caps are fully nested in the block, start by torquing fasteners 1-20 to 22 ft-lbs, and then loosen them. Push the crank forward to full thrust. Re-torque fasteners 1- 10 to 15 ft-lbs, then add 80 degrees of torque angle. Then, torque fasteners 11-20 to 15 ft-lbs and loosen them to hand tight. Re-torque them to 15 ft-lbs and add 53 degrees of torque angle. Now torque fasteners 21-30 to 18 ft-lbs, doing them as pairs per each main cap. The side bolts can be reused but need to be cleaned and have a small bead of sealer put under the head of the bolt because they thread into the crankcase.

 

8. During the torquing portion of the process, the extreme-pressure lube applied to the bottom of the fastener head helps minimize friction that would otherwise result in a false torque reading.

8. During the torquing portion of the process, the extreme-pressure lube applied to the bottom of the fastener head helps minimize friction that would otherwise result in a false torque reading.

 

9. Fasteners need to have stretch added to them in order to do their job correctly. A large breaker bar is used to twist the fastener with this degreereading socket attachment (Snap-On PN TA-360 and GM PN J 36660) between the socket and breaker bar. By resting the stretch socket stop on an immovable part of the engine block (left hand, holding stop against engine block), the amount the fastener is twisted, or stretched, can be exactly measured in degrees.

9. Fasteners need to have stretch added to them in order to do their job correctly. A large breaker bar is used to twist the fastener with this degreereading socket attachment (Snap-On PN TA-360 and GM PN J 36660) between the socket and breaker bar. By resting the stretch socket stop on an immovable part of the engine block (left hand, holding stop against engine block), the amount the fastener is twisted, or stretched, can be exactly measured in degrees.

 

10. The crank endplay should then be checked. This is performed by mounting a dial indicator on one end of the crank and prying between one of the crank throws and a main cap with a screwdriver. The endplay should total 0.003 to 0.004 inch.

10. The crank endplay should then be checked. This is performed by mounting a dial indicator on one end of the crank and prying between one of the crank throws and a main cap with a screwdriver. The endplay should total 0.003 to 0.004 inch.

 

11. The Gen III V-8 uses a key on the snout of the crank to drive the oil pump and lock the crank gear in place—but it doesn’t hold the harmonic balancer on production cranks. On this Lunati crank, the front drive will be keyed to the crank. Hammer the key in place with a shot-filled mallet.

11. The Gen III V-8 uses a key on the snout of the crank to drive the oil pump and lock the crank gear in place—but it doesn’t hold the harmonic balancer on production cranks. On this Lunati crank, the front drive will be keyed to the crank. Hammer the key in place with a shot-filled mallet.

 

12. Knock the crank gear onto the crank snout using a 1-1/2-inch inside diameter round aluminum tube and shot-filled mallet. The tube needs to be aluminum too so the gear face isn’t marred in the process — remember, the oil pump slides over this area. Also, the key slot in the gear needs to be indexed over the key so it all goes on smoothly.

12. Knock the crank gear onto the crank snout using a 1-1/2-inch inside diameter round aluminum tube and shot-filled mallet. The tube needs to be aluminum too so the gear face isn’t marred in the process — remember, the oil pump slides over this area. Also, the key slot in the gear needs to be indexed over the key so it all goes on smoothly.

 

Installing a Camshaft

 

1. Coat the cam liberally with engine oil. W2W has their own cam created for this engine based on their experience (W2W PN 8606). The basic information on this cam is it has 239/241 degrees intake/exhaust duration at 0.050 inches lift and 0.570/0.570 inches of lift. Spread a light coat of 30-weight oil around the cam journals before you slide the cam into the engine.

1. Coat the cam liberally with engine oil. W2W has their own cam created for this engine based on their experience (W2W PN 8606). The basic information on this cam is it has 239/241 degrees intake/exhaust duration at 0.050 inches lift and 0.570/0.570 inches of lift. Spread a light coat of 30-weight oil around the cam journals before you slide the cam into the engine.

 

2. Install the oiled-up camshaft now, along with the timing chain. The LS1/LS6 Gen III camshafts are hollow in the center, which makes them light and easy to install. Slide a 3/8- inch extension up inside the cam for leverage and control to help you negotiate the cam past the engine block cam journals.

2. Install the oiled-up camshaft now, along with the timing chain. The LS1/LS6 Gen III camshafts are hollow in the center, which makes them light and easy to install. Slide a 3/8- inch extension up inside the cam for leverage and control to help you negotiate the cam past the engine block cam journals.


 
LSB

 

Installing the Connecting Rods/Pistons

 

1. Lightly wipe down the bores with a non-linting towel soaked in 100 percent virgin fast-dry acrylic lacquer thinner. Then drool a small amount of 30-weight engine oil into the bores and spread it evenly around every inch of the bore with your clean hand.

1. Lightly wipe down the bores with a non-linting towel soaked in 100 percent virgin fast-dry acrylic lacquer thinner. Then drool a small amount of 30-weight engine oil into the bores and spread it evenly around every inch of the bore with your clean hand.

 

2. Wipe a very light amount of 30-weight oil on the rings and thrust faces of the piston.

2. Wipe a very light amount of 30-weight oil on the rings and thrust faces of the piston.

 

3. With the bore glistening with freshly spread oil, rotate the crank journal until it’s at the bottom of its stroke. This gives you the maximum amount of room to work when guiding the big end of the rod down inside the bore.

3. With the bore glistening with freshly spread oil, rotate the crank journal until it’s at the bottom of its stroke. This gives you the maximum amount of room to work when guiding the big end of the rod down inside the bore.

 

4. Make sure you have the rods/pistons installed with the proper clocking in relation to the pistons, because the bearings are chamfered on only one side to clear the rolled fillet on the crank. Getting this switched around will result in drastic metal-on-metal wear. By the way, the fine scratches in the bearing face are from the bearing ID measuring device on the rod bore machining station and are not a concern for the engine.

4. Make sure you have the rods/pistons installed with the proper clocking in relation to the pistons, because the bearings are chamfered on only one side to clear the rolled fillet on the crank. Getting this switched around will result in drastic metal-on-metal wear. By the way, the fine scratches in the bearing face are from the bearing ID measuring device on the rod bore machining station and are not a concern for the engine.

 

5. Since the rod bolts are set on their final clamping load with torque angle, coat the bottom of the rod bolt heads with a very light coat of extreme-pressure lube.

5. Since the rod bolts are set on their final clamping load with torque angle, coat the bottom of the rod bolt heads with a very light coat of extreme-pressure lube.

 

6. Load the piston into a ring compressor of the appropriate bore diameter to help get the piston into the bores. As a tip, wipe down the ring compressor with the lacquer thinner and oil, just like the bore, before loading the piston into it.

6. Load the piston into a ring compressor of the appropriate bore diameter to help get the piston into the bores. As a tip, wipe down the ring compressor with the lacquer thinner and oil, just like the bore, before loading the piston into it.

 

7. Be patient and careful during the initial push on the piston, as this is when the rings go past the ending of the ring compressor and into the engine block bore. Sometimes, the rings will get caught up on this transition. You can try wiggling the assembly to see if you can get past this point, but usually it’s best to just pull the piston/rod combo out of the bore, pull the piston through the ring compressor, and restart the process. Often, this problem is caused by the ring compressor not being fully seated on the deck surface of the block.

7. Be patient and careful during the initial push on the piston, as this is when the rings go past the ending of the ring compressor and into the engine block bore. Sometimes, the rings will get caught up on this transition. You can try wiggling the assembly to see if you can get past this point, but usually it’s best to just pull the piston/rod combo out of the bore, pull the piston through the ring compressor, and restart the process. Often, this problem is caused by the ring compressor not being fully seated on the deck surface of the block.

 

8. With the piston in the bore, remove the ring compressor and switch to a light mallet to tap the piston down in the bore while guiding the big end of the rod onto the crank journal.

8. With the piston in the bore, remove the ring compressor and switch to a light mallet to tap the piston down in the bore while guiding the big end of the rod onto the crank journal.

 

10. Torque the ARP 7/16-inch rod bolts in the steel Oliver rods to 30 ftlbs. The stock rod bolts would only be torqued to 15 ft-lbs.

10. Torque the ARP 7/16-inch rod bolts in the steel Oliver rods to 30 ftlbs. The stock rod bolts would only be torqued to 15 ft-lbs.

 

11. Place the bolt stretch attachment on a breaker bar and add an additional 40 degrees of torque angle into the ARP bolts to achieve the appropriate clamping load on the rod cap. The stock rod bolts would get 60 degrees of torque angle.

11. Place the bolt stretch attachment on a breaker bar and add an additional 40 degrees of torque angle into the ARP bolts to achieve the appropriate clamping load on the rod cap. The stock rod bolts would get 60 degrees of torque angle.

 

Piston Talk

If you plan on using the stock short block with heads that have been machined more than 0.050 inches and a camshaft similar to the one used here, be prepared to spend some money buying aftermarket pistons with valve reliefs or having small valve reliefs cut in the stock pistons. The early Motorola Cup rules this engine was originally created for required stock pistons, but they didn’t limit valve reliefs, so the engine designers put as much compression, valve lift, and duration in the engine as possible. The piston on the left with the valve reliefs is a remnant from W2W’s days of supplying these early racing engines. The piston on the right is a stock unit.

 

sa86_fullbook_ls1ls6_page_113_image_0002

 

Actually, if you need valve reliefs, W2W recommends installing a set of aftermarket forged aluminum pistons. This is because the cost difference between a set of stock pistons with the valve reliefs machined in them and the forged aluminum pieces is a few hundred dollars — a small price for a lot of insurance towards keeping your engine together. W2W has used heads milled about 0.040 inch, which nets a 62-cc chamber size, on the street with no problems. They’ve also cut heads up to 0.060 inch, which produces about a 57- cc chamber size, and had no problems in racing applications.

Piston: In the Hole or Popup?

The next important step is to check how much the piston comes out of (or stays down in) the bore during the crank stroke. This is a good parameter to check even if you haven’t changed anything on the stock short block. Here’s how you do it:

 

1. Locate the dial indicator on one side of the top of the piston at TDC. With the crank held in place, push on the thrust face of the piston and set the dial indicator at zero.

1. Locate the dial indicator on one side of the top of the piston at TDC. With the crank held in place, push on the thrust face of the piston and set the dial indicator at zero.

 

2. Now, push on the other side of the top of the piston and read the dial indicator.

2. Now, push on the other side of the top of the piston and read the dial indicator.

 

3. Divide this number by two and pivot the piston back until th

3. Divide this number by two and pivot the piston back until  the dial indicator reads that number.

 

4. Zero out the dial indicator.

4. Zero out the dial indicator.

 

5. Rotate the base until the indicator is reading the block deck height. In this case, the piston is popping 0.010 inch out of the bore. This is normal as the Gen III V-8 is designed as a negative deck-height engine. This means the piston is meant to stop its upward motion slightly above the deck face. Doing this increases the squish effect of the piston approaching the combustion chamber, focusing the combustion pressure in the chamber for maximum force transferred to the piston. You should degree the cam at this point, following the procedure on page 95.

5. Rotate the base until the indicator is reading the block deck height. In this case, the piston is popping 0.010 inch out of the bore. This is normal as the Gen III V-8 is designed as a negative deck-height engine. This means the piston is meant to stop its upward motion slightly above the deck face. Doing this increases the squish effect of the piston approaching the combustion chamber, focusing the combustion pressure in the chamber for maximum force transferred to the piston. You should degree the cam at this point, following the procedure on page 95.

 

Oiling System and Water Pump

1. The modified factory oil pump has been located and mounted to the front of the crank snout (see Chapter 6 for tips on the factory oil pump locating process). The pressurized oil flows down the side of the engine block in a large main gallery. A welsh plug needs to be installed in the block 2.5-mm deep with a tolerance of +/- 0.3 mm to get the oil to flow down this gallery (shown being installed). When an engine is torn down, this plug is removed to clean the main oil gallery with a brush. Notice the custom W2W billet outlet on the factory pump — this is used to mate up with the internal passage that has been ported to increase oil flow out of the pump and mate up with the custom dry-sump oil pan.

1. The modified factory oil pump has been located and mounted to the front of the crank snout (see Chapter 6 for tips on the factory oil pump locating process). The pressurized oil flows down the side of the engine block in a large main gallery. A welsh plug needs to be installed in the block 2.5-mm deep with a tolerance of +/- 0.3 mm to get the oil to flow down this gallery (shown being installed). When an engine is torn down, this plug is removed to clean the main oil gallery with a brush. Notice the custom W2W billet outlet on the factory pump — this is used to mate up with the internal passage that has been ported to increase oil flow out of the pump and mate up with the custom dry-sump oil pan.

 

2. To make sure the engine block oil gallery plug stays in place during extreme power production, you should apply a liberal coating of JB Weld onto the rim of the welsh plug. If this plug did come loose during operation, the oil pressure in the engine would drop to zero, because all the oil would pour back into the pan.

2. To make sure the engine block oil gallery plug stays in place during extreme power production, you should apply a liberal coating of JB Weld onto the rim of the welsh plug. If this plug did come loose during operation, the oil pressure in the engine would drop to zero, because all the oil would pour back into the pan.

 

3. The fabricated ARE dry-sump oil pan has a receiver on it to plumb the oil from the dry-sump reservoir to the pump. This fitting has two O-rings on it to seal the two fittings together. W2W recommends putting a light skim of 30-weight on the O-rings so they’ll slide into the hole with little resistance.

3. The fabricated ARE dry-sump oil pan has a receiver on it to plumb the oil from the dry-sump reservoir to the pump. This fitting has two O-rings on it to seal the two fittings together. W2W recommends putting a light skim of 30-weight on the O-rings so they’ll slide into the hole with little resistance.

 

4. This timing-chain dampener, GM PN 88958607, was originally designed for the production LS1/LS6 Gen III V- 8 engine but didn’t make it past the bean counters. It works very well to minimize chain activity/movement in high-RPM situations. W2W likes to use it in all of its performance engines to improve durability and power production over the life of the engine. The only problem with this is that some of the blocks don’t have the holes drilled and tapped. But the part does come with a template to help you install it on an undrilled block. Apply blue Loctite to the threads and torque the fasteners to 18 ft-lbs.

4. This timing-chain dampener, GM PN 88958607, was originally designed for the production LS1/LS6 Gen III V- 8 engine but didn’t make it past the bean counters. It works very well to minimize chain activity/movement in high-RPM situations. W2W likes to use it in all of its performance engines to improve durability and power production over the life of the engine. The only problem with this is that some of the blocks don’t have the holes drilled and tapped. But the part does come with a template to help you install it on an undrilled block. Apply blue Loctite to the threads and torque the fasteners to 18 ft-lbs.

 

5. A plastic insert that many call the “barbell restrictor” is used to stop the pressurized oil from the oil pump from continuing down the main oil gallery. The barbell redirects this oil into the oil filter. The oil then comes back up through a different passage to the main gallery. The other end of the barbell keeps the oil from going toward the back of the block. Install the barbell restrictor by lightly lubricating it with 30-weight oil and pressing it into the bore at the back of the engine block. It needs to be installed with the O-ring going in last — you should still be able to barely see the O-ring when the restrictor is properly installed. The rear cover plate locks the barbell restrictor in place.

5. A plastic insert that many call the “barbell restrictor” is used to stop the pressurized oil from the oil pump from continuing down the main oil gallery. The barbell redirects this oil into the oil filter. The oil then comes back up through a different passage to the main gallery. The other end of the barbell keeps the oil from going toward the back of the block. Install the barbell restrictor by lightly lubricating it with 30-weight oil and pressing it into the bore at the back of the engine block. It needs to be installed with the O-ring going in last — you should still be able to barely see the O-ring when the restrictor is properly installed. The rear cover plate locks the barbell restrictor in place.

 

6. This engine is set up with an external- scavenge dry-sump oiling system. The system is great at getting oil out of the engine that isn’t lubricating or cooling at that moment, which is good to keep oil from roping on the crank and doing other power-eating activities. Before you install the oil pan, the front and rear covers need to be installed (see page 116). The –12 AN fitting at the front of the oil pan (on the left) is plumbed to the bottom of the dry-sump oil reservoir for uninterrupted oil flow to the stock oil pump, which provides oil to the bearings and other critical components. The two threaded holes toward the rear of the oil pan are for the oil pickups. This pan is not a stressed-member like the factory pan, so it doesn’t need to be aligned like the factory pan. Note the custom billet aluminum front drive spud on the crank snout for the racing harmonic balancer and front drive pulleys.

6. This engine is set up with an external- scavenge dry-sump oiling system. The system is great at getting oil out of the engine that isn’t lubricating or cooling at that moment, which is good to keep oil from roping on the crank and doing other power-eating activities. Before you install the oil pan, the front and rear covers need to be installed (see page 116). The –12 AN fitting at the front of the oil pan (on the left) is plumbed to the bottom of the dry-sump oil reservoir for uninterrupted oil flow to the stock oil pump, which provides oil to the bearings and other critical components. The two threaded holes toward the rear of the oil pan are for the oil pickups. This pan is not a stressed-member like the factory pan, so it doesn’t need to be aligned like the factory pan. Note the custom billet aluminum front drive spud on the crank snout for the racing harmonic balancer and front drive pulleys.

 

7. Then bolt the valley cover in place. This is as simple as it sounds — just install the cover with the preformed seal and torque the fasteners to 18 ftlbs in a radial pattern. This is the later ’02 LS6 valley cover, which you can tell by the vent valve near the right side.

7. Then bolt the valley cover in place. This is as simple as it sounds — just install the cover with the preformed seal and torque the fasteners to 18 ftlbs in a radial pattern. This is the later ’02 LS6 valley cover, which you can tell by the vent valve near the right side.

 

8. The lifter trays, with four stock roller lifters installed in each, should now be dropped in the engine. These lifter trays are very cool in that they hold the lifters in place on the roller cam. Also, if you want to make a cam change once the engine has been assembled, rotating the cam one revolution will push the lifters up into the trays, allowing quick cam changes

8. The lifter trays, with four stock roller lifters installed in each, should now be dropped in the engine. These lifter trays are very cool in that they hold the lifters in place on the roller cam. Also, if you want to make a cam change once the engine has been assembled, rotating the cam one revolution will push the lifters up into the trays, allowing quick cam changes.

 

9. A good trick to improve the oil control in a hot-rod Gen III V-8 is to drill these 1/2-inch drain holes in the lower face of the lifter retainer trays above each lifter. On a production engine, having engine oil pooling here is acceptable, but on a high-rpm engine, having oil lying around only costs you power and causes the oil to foam and get hot.

9. A good trick to improve the oil control in a hot-rod Gen III V-8 is to drill these 1/2-inch drain holes in the lower face of the lifter retainer trays above each lifter. On a production engine, having engine oil pooling here is acceptable, but on a high-rpm engine, having oil lying around only costs you power and causes the oil to foam and get hot.

 

10. The lifter trays are held in the engine block with 6-mm bolts torqued to 106 in-lbs.

10. The lifter trays are held in the engine block with 6-mm bolts torqued to 106 in-lbs.

 

11. The water pump can then be bolted into place. Apply 18 ft-lbs of torque to the fasteners.

11. The water pump can then be bolted into place. Apply 18 ft-lbs of torque to the fasteners.

 

Building Cylinder Heads

 

1. The cylinder heads are easy to assemble because they’re designed to be easy to manufacture. Since the 2002, the stock LS6 intake valves are hollow and the exhaust valves are sodium/potassium filled, which is a high-performance option on many hot-rod engines. These valves will work great in many demanding applications. Make sure you check the valvetrain geometry because the ’02 LS6 valves are 0.6-mm longer than previous LS valves to account for the smaller base circle on the ’02 LS6 camshaft.

1. The cylinder heads are easy to assemble because they’re designed to be easy to manufacture. Since the 2002, the stock LS6 intake valves are hollow and the exhaust valves are sodium/potassium filled, which is a high-performance option on many hot-rod engines. These valves will work great in many demanding applications. Make sure you check the valvetrain geometry because the ’02 LS6 valves are 0.6-mm longer than previous LS valves to account for the smaller base circle on the ’02 LS6 camshaft.

 

2. The rockers are easy to install as they are mounted to a single tie bar per head that holds all the rockers. The entire rocker system can be slid onto the head and bolted on with eight 8- mm diameter, 8-mm hex-head bolts per head that are torqued to 22 ft-lbs. The rockers should be lubed up fully with 30-weight oil, but especially on the ends where the rockers touch the pushrods and valves. The Gen III V8 valvetrain preload is non-adjustable, so if a change has been made to the deck height, camshaft base circle, or other valvetrain geometry altering changes, the valvetrain will need to be adjusted to make sure the proper preload exists on the hydraulic lifters. Many aftermarket companies are now offering adjustable rockers as a solution. But a simple way to attain the correct preload is through installing different length pushrods. The valvetrain preload is checked by spinning the pushrod in your fingers while tightening down the rocker tie bar bolts. The factory preload has the pushrod becoming difficult to spin in your fingers about 1.5 turns of the 8 mm bolts before the tie bar seats to the stands. W2W recommends using a little more than a 1/2 turn of valvetrain preload with the engine hot. This prevents the common thrashing valvetrain noise at low rpm on performance LS1 engines. Getting the valvetrain geometry and preload correctly adjusted with pushrod length is a big deal. So spend the time to get it right.

2. The rockers are easy to install as they are mounted to a single tie bar per head that holds all the rockers. The entire rocker system can be slid onto the head and bolted on with eight 8- mm diameter, 8-mm hex-head bolts per head that are torqued to 22 ft-lbs. The rockers should be lubed up fully with 30-weight oil, but especially on the ends where the rockers touch the pushrods and valves. The Gen III V8 valvetrain preload is non-adjustable, so if a change has been made to the deck height, camshaft base circle, or other valvetrain geometry altering changes, the valvetrain will need to be adjusted to make sure the proper preload exists on the hydraulic lifters. Many aftermarket companies are now offering adjustable rockers as a solution. But a simple way to attain the correct preload is through installing different length pushrods. The valvetrain preload is checked by spinning the pushrod in your fingers while tightening down the rocker tie bar bolts. The factory preload has the pushrod becoming difficult to spin in your fingers about 1.5 turns of the 8 mm bolts before the tie bar seats to the stands. W2W recommends using a little more than a 1/2 turn of valvetrain preload with the engine hot. This prevents the common thrashing valvetrain noise at low rpm on performance LS1 engines. Getting the valvetrain geometry and preload correctly adjusted with pushrod length is a big deal. So spend the time to get it right.

 

3. You should check the valvetrain geometry with the top end bolted together. The ’01 and earlier LS1 and LS6 have the same 7.400-inch pushrod lengths from the factory. W2W often uses different length pushrods because of head milling and their desire to run a lighter lifter preload than was recommended by the factory (to release some hidden power). Their most common length pushrod ends up being a Smith Brothers 7.325-inch pushrod for the ’02 and later LS6 cam. With a ported oil pump body and increased oil pressure pop-off spring pushing more oil through the engine, W2W recommends setting a 0.035-inch opening in the Smith Brothers pushrops to control oil flow to the top of the engine.

3. You should check the valvetrain geometry with the top end bolted together. The ’01 and earlier LS1 and LS6 have the same 7.400-inch pushrod lengths from the factory. W2W often uses different length pushrods because of head milling and their desire to run a lighter lifter preload than was recommended by the factory (to release some hidden power). Their most common length pushrod ends up being a Smith Brothers 7.325-inch pushrod for the ’02 and later LS6 cam. With a ported oil pump body and increased oil pressure pop-off spring pushing more oil through the engine, W2W recommends setting a 0.035-inch opening in the Smith Brothers pushrops to control oil flow to the top of the engine.

 

Installing and Torquing the Cylinder Heads

 

1. The CNC-ported cylinder heads are installed using a stock-type Cometic sandwich gasket that has three thin pieces of stainless covered by a sealing material. Depending on the compression ratio they need to achieve, W2W uses everything from the stock 0.057-inch-thick stock gasket, down to a 0.040-inch-thick gasket to get the compression ratio up to 12:1 on the race engines they build. W2W likes to use the Cometic gasket, as it has proven to be extremely durable under severe conditions.

1. The CNC-ported cylinder heads are installed using a stock-type Cometic sandwich gasket that has three thin pieces of stainless covered by a sealing material. Depending on the compression ratio they need to achieve, W2W uses everything from the stock 0.057-inch-thick stock gasket, down to a 0.040-inch-thick gasket to get the compression ratio up to 12:1 on the race engines they build. W2W likes to use the Cometic gasket, as it has proven to be extremely durable under severe conditions.

 

2. As in the case of the other critical fasteners, apply grease under heads of the cylinder-head fasteners.

2. As in the case of the other critical fasteners, apply grease under heads of the cylinder-head fasteners.

 

sa86_fullbook_ls1ls6_page_118_image_0005

3. To begin, snug the head bolts numbered 1-10 in the illustration above to 22 ft-lbs.

3. To begin, snug the head bolts numbered 1-10 in the illustration above to 22 ft-lbs.

 

4. Next, draw a vertical line on the top of each head bolt with a Sharpie permanent felt marker. This is used as a reference when going through the torque angle tightening sequence — in case you get mixed up as to which ones you’ve already done.

4. Next, draw a vertical line on the top of each head bolt with a Sharpie permanent felt marker. This is used as a reference when going through the torque angle tightening sequence — in case you get mixed up as to which ones you’ve already done.

 

5. As with the other important fasteners on these engines, head bolts 1-10 are torque angled first to 76 degrees. Then, head bolts 1-8 are torque angled 76 degrees more. For head bolts 9 and 10, add 38 degrees of torque angle. Next, torque bolts 11-15 to 22 ft-lbs in the order shown above. From there, torque down the five 8-mm bolts at the top of the head to 18 ft-lbs. Then install the steam vent crossovers at the front of the block the steam hole blockoffs at the rear of the block. Use this diagram to torque the 10 intake manifold bolts to 44 in-lbs on the first pass, then to 89 in-lbs in the final sequence (see page 98 for torquing illustration). Also, install the throttle body and MAF sensor on the front of the intake.

5. As with the other important fasteners on these engines, head bolts 1-10 are torque angled first to 76 degrees. Then, head bolts 1-8 are torque angled 76 degrees more. For head bolts 9 and 10, add 38 degrees of torque angle. Next, torque bolts 11-15 to 22 ft-lbs in the order shown above. From there, torque down the five 8-mm bolts at the top of the head to 18 ft-lbs. Then install the steam vent crossovers at the front of the block the steam hole blockoffs at the rear of the block. Use this diagram to torque the 10 intake manifold bolts to 44 in-lbs on the first pass, then to 89 in-lbs in the final sequence (see page 98 for torquing illustration). Also, install the throttle body and MAF sensor on the front of the intake.

 

s1

 

The engine tested here used the aftermarket components shown in this chapter, but engines with stock short-blocks have made similar power. The key components to make this power include the GMPP CNC-ported cylinder heads (which yield a 10.5:1 compression ratio), the GMPP Showroom Stock camshaft or similar aftermarket cam (less than 0.600 inch lift), 1- 3/4- inch primary long-tube headers, 38-lb/hr injectors, F.A.S.T. controller, and open-element air cleaner. Increasing the compression to 12:1 would increase the horsepower curve about 20 to 30 hp over the last 1/3 of the power curve, but you’d need to run 100 octane gas to prevent the engine from detonating itself to death.

The engine tested here used the aftermarket components shown in this chapter, but engines with stock short-blocks have made similar power. The key components to make this power include the GMPP CNC-ported cylinder heads (which yield a 10.5:1 compression ratio), the GMPP Showroom Stock camshaft or similar aftermarket cam (less than 0.600 inch lift), 1- 3/4- inch primary long-tube headers, 38-lb/hr injectors, F.A.S.T. controller, and open-element air cleaner. Increasing the compression to 12:1 would increase the horsepower curve about 20 to 30 hp over the last 1/3 of the power curve, but you’d need to run 100 octane gas to prevent the engine from detonating itself to death.

 

 

Written by Will Handzel and Posted with Permission of CarTechBooks

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