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HorsePower Research


In this thread we are going to outline and show some of the items you might find in a high HP LSx build. In this particular example this is going to be a forced induction, alcohol engine running in excess of 2000 hp.

Over the next days / weeks you will see each item being used and we will try and highlight details on why you might need something like this in your engine, or why you wouldn't.

Please feel free to comment, like, or ask questions along the way. For privacy of the customer, there will be no pictures shown of the car or final package installed, sorry.


*There are many ways to build an engine in this HP range depending on use, class rules, and mostly budget. This is showing just one way. Enjoy





Stay Tuned!

BoostedC3

Sub'd!

schpenxel

Sub'd

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In these articles we are going to assume nothing. Many of you know a lot of this information but it will be presented to the reader having only the basic automotive knowledge.


#1 Crankshafts

There are a number of different ways to make and design crankshafts, the three main ways are; casting, forging, and billet. Depending on the budget, power level, use, and number of units being built what might be the best way to go about it.


-CAST-
Casting is probably the most popular off all ways, especially for production use due to the quick and economical way to manufacture the cranks. If you are going to produced crank shafts by the 10's of thousands in one rough size and shape, it is very easy to turn them out quickly without a lot of cost. Production, low HP, low RPM engines are fine with cast crankshafts and can run for hundreds of thousands of miles for a normal driver. Prices can range from $300-600 ea

-FORGED-
Forging is the most popular aftermarket upgrade when people talk about a "built" engine. The forging process produces a more compacted material which leads to a much stronger piece at the end. You have a few more options when it comes to the material itself which, again is going to produce a stronger final piece. You will be limited slightly in design with these as there is a high cost in making the forging dies when making the blanks. Counter weight design and stroke are generally limited on how much you can add or move. In the last few years the OE has switched to forged crankshafts for the high performance cars like the LS7, LS9, LSA and similar engines. Because the forging dies are more limited on what the final product is, and the machine wear/time to produce the final product is more....these generally will cost slightly more than a casting. Custom machining can add to this even more. Material is typically 4340. Pricing on average can be $800-1800

-BILLET-
When you select a billet crankshaft you have even more control over the final design. Because the crankshaft starts as a solid block of steel, counter weight design, counter weight placement, stroke, main, and rod journals can all be controlled to what ever you would like to do. Because the piece starts as a forged billet, and you have more control still over material choices you can produce an even stronger crankshaft than forged. Most top level drag racing, including Top Fuel, and top level road race cars will use billet crankshafts. Material can be 4340, 300M or other specialty materials. Pricing generally starts around $3000 and can be over $7000 depending on design and material used. The other downside, other than the cost, is the build time. Billet cranks are only made by a handful of companies and lead times can top 10-14 weeks.


-Counter Weights-

Counter weight design can, and is, a vital component of any engine build. Each OE is slightly different in how they produce crankshafts, some OE engines will design and use crankshafts that have counter weights on each (or each pair), of rods to give a more naturally balanced crankshaft. Chevy for what ever reason (probably cost), chose to eliminate the counter weights from the center of their crankshafts. By doing so this typically makes the front and rear counter weights the largest, and reduce as they make their way to the center were no counter weight is included, cast or forged. As you can see in the picture below a forged LS crankshaft is on the right with the standard counterweight design as compared to a fully counter weighted crank on the left...in this case billet.




full counter weighted crank on the left, standard Chevy on the right


Adding the additional counter weights to the middle of the crankshaft will help strengthen the crankshaft even more, and reducing its tendency to S shape under load. Without the weights there, the 2 and 4 journals are acting like bike cycle pedals, trying to twist the crankshaft. CCW (Center Counted Weighted) crankshafts will help to reduce this by naturally balancing out the engine. By greatly reducing the chance to S bend the crank will greatly increase main bearing life of most performance engines. CCW crankshafts are highly suggested to be used in high RPM applications and high HP applications. You will find CCW crankshafts used in NASCAR, ALMS, NHRA, and other pro level racing. Be it a build to make 1500 and more, or a 500hp LS turning 9000 RPM, a CCW crankshaft is the way to go. For the last 10 years, typically only billet crankshafts could be used for a CCW LS crank, but there are a handful of CCW forged crankshafts to help bring some of the costs down.



Our build.


This LS turbo build is using both a billet, and CCW crankshaft by Sonny Bryant. Because of the high HP requirements of the build by the customer (topping 2000hp) the crankshaft needs to be a strong as it possibly can as it will see a lot of load by the power demands and also continued high RPM use while making passes. This, the center piece of the engine, needs to be one of the most reliable parts of the build.




This particular crankshaft topped the $4000 mark by being a billet piece as well as a CCW design. Another interesting feature using two thrust bearings which I will cover in the next installment as we go over the block as well.





In closing, there are a number of ways you can build your engine and many price points to choose from as well as design. Just the crankshaft costs can range $400-$8000 before ever assembling the engine. While it would be IDEAL for every engine to use a billet CCW crankshaft, in reality, most builds it is not needed. Speak to your engine builder as what be right for your particular build.

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#2 Thrust


High HP builds can place a lot of stress on internal components of the engine. Many of us think to forged pistons, or better connecting rods but something that might be overlooked is as simple as thrust.

All engines have some thrust pressure against them, be it from a simple stock clutch or big stall converter. This is one reason you need to take steps during the assembly process to measure thrust and make sure it is enough for your particular build process.


checking thrust

You check thrust just after the crankshaft is placed in the block to see how much movement you have. To much and you inspect bearings and the crankshaft for issues, to little and you again..inspect and correct. Install all caps, other than thrust and measure again, install thrust bearing/cap measure before and after the cap is tight. All of this is done to make sure the crank has enough clearance to maintain oil between surfaces when it is loaded. This distance can vary again depending on transmission type, engine use and the loads it is going to see.

The problem can lie however, when loads exceed what this small amount of oil and bearing surface can handle. While LS engines have 5 main bearings to support the crankshaft in rotation there is only one small surface to keep the crankshaft from moving to far fore or aft. Big stall converters, and a lot of HP can quickly lead to excessive pressure on the crankshaft and damaged / spun thrust bearings. So what are you to do?

You could increase the space, or modify the bearing to allow more oil but this in turn will create an internal oil leak and drop oil pressure to the engine causing other issues.

One of the ways to go about solving this issue is using a roller thrust bearing in addition to the standard thrust. In this build we felt the roller front thrust will give us the protection needed to not spin the normal thrust and keep clearances closer to normal as to not create an oil pressure issue.


Below you can see the roller thrust as it is installed on the nose of the crankshaft itself.


base plate and rollers installed



complete roller thrust assembly



In order to do this, the crank must be setup for it, and the block must have special machine work to the block and cap as you can see here on #1


#1 main area cut for roller thrust bearing



Roller installed






Shown here with the cap removed of course so you can see how it fits down into the block itself.

Of course this now requires much more time to setup as you have two surfaces to measure and check during install but in the end you have a much more reliable design to maintain crankshaft location in the engine block itself and less chance of bearing issues.

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#3 Lifters.


I am choosing to do the lifters before addressing the rods and pistons for a few reasons. In some ways the lifter is often a very over looked part of the equation in a engine build but a vital one. Most people might only think of hydraulic or solid lifters....roller or tappet, but give little thought sometimes to other aspects of the lifter and how that can help a high performance engine survive.

Since all most all domestic engines built since 1986 have had roller lifters I am going to leave out the flat tappet lifters for this discussion.

Hydraulic

• OEM choice for almost all engines
• "self" adjusting for the most part
• does not require adjustable rocker arms
• easy to use
• quiet operation
• can have issues with big spring pressure and/or high RPM
• mass produced so can be had at a economical price

Solid

• Requires more costly adjustable rocker arms
• nosier operation
• typically requires maintenance for proper adjustment
• great for valvetrain stability and high RPM use
• almost required when running high spring pressures.

For the most part, that is what most think of when looking at what kind of lifter to buy and in a way that does narrow it down and should be one of the first things looked at, because cam profiles will also have to match to which lifter you are going to use. Typically speaking you wouldn't run a solid lifter on a hydraulic cam or vice versa (in some rare cases it is done).

Now what about the lifter itself?

Lifter Diameter:
There are a number of different diameters of lifters that can be used from a stock SBC of 0.842" up to well over 1" in diameter. Of course what you choose to do here is going to depend on what kind of block you have and how much machine work can or is done to it. The larger the body diameter you have the larger wheel you can use as a follower, which we will talk about below. Going to a bigger body lifter typically will allow room more offset pushrod locations, less stress on the lifter body itself, and again more stability in the valvetrain system. With this build, we are using a Jesel DLC coated lifter 0.937" in diameter to gain the room for the bigger wheel shown below.



Jesel link bar, solid roller. 0.937" in diameter




Roller Diameter:
A SBC/LS lifter is going to use a roller diameter of 0.700". This is pretty standard issue and is generally retained on what you would see on a lot of "performance" lifters like LS7's, Comp R, or a drop in Morel or Johnson lifter. One step up from this is going to a 0.750" roller which will help take some stress off of the camshaft itself and can reduce the load placed on both the wheel and the lobe, similar to a big tire in drag racing. By using a larger wheel, you also slow the wheels speed over the cam which reduces friction and heat. This will also allow for a greater redline, given the proper components. Pricing does generally go up when moving into this range. For very aggressive cam profiles this is something that should be looked at very closely and also for those doing extended higher RPM use but do not want to go through the process of using a bigger diameter lifter body. In the case of this build, we are using a 0.850" diameter wheel, again to better stabilize the valve train and reduce stress on the lifters due to the spring rates.



Left to Right: Jesel with a 0.850" wheel, Morel with a 0.750" wheel, stock LS7 with a 0.700" wheel. You can also see the body difference in body size too compared to the stock replacements 0f 0.842"


Lifter travel:

Here there are two kinds of travel. Travel within the lifter itself in the case of a hydraulic but also lifter travel in the bore of the block.

The first is easy enough when dealing with hydraulic lifters. Typically a OE type lifter will have a far greater range to deal with production tolerances and growth of the engine in different climates. A OE lifter might have as much as a quarter of an inch in plunger travel. Some performance lifter applications may see only 0.100 or less making pushrod measurements on a non adjustable valvetrain extremely critical and should be done by someone that has checked before.

Lifter travel within the block itself. Different blocks may use different lifter bore sizes, and different cams with different diameters, base circles will also have different lifter travels as well. All of this is critical so the lifter is correctly placed again for stability but also oiling. Solid or hydraulic the lifter must see pressurized oil for itself and also to supply oil to the rocker arms and valvetrain. In the case of the Jesel lifters we are using they not only have a narrow band for oiling but also small inlets for pressurized oil feeds directly to the axle wheels.







You can see how the oil travels inside the lifter from this Comp Cam's cutaway below. They also mention a taller body for use in different sized lifter bores as well.



Comp Lifter cut away



Special Features:

Every aspect of a build like this must be looked at, and do not think that the pushrods always have to be right in the middle of the lifter because the geometry of a normal V8 might not be correct. In the case of this build, that is what happened. To get the pushrods correctly lined up with the valves and rocker arms above, we had to use a offset lifter only on one side. Companies like Jesel can do these in a variety of ways and offsets depending on what the customer requires.



Jesel offset

Also we chose to do a few other things like using a DLC coated lifter body to drop frictional losses and help lifter wear. The Jesel lifter also contains a roller bearing on the wheel. Some may feel a bushing is better suited here to reduce the number of moving parts or that it might be more reliable. We, and Jesel, feel the frictional loss by using the bearing in this application is the better way to go.

So for a recap on things you need to know to make a correct decision on lifters.

-Solid or Hydraulic
-What diameter am I using or need to use?
-Do I need a larger wheel?
-Do I need to correct any geometry issues?
-Does my block have any special requirements due to oiling?











RACE USE ONLY - NON OE Block

In the event you are building your own billet block, or possibly using a carbon matrix NASCAR block you might find yourself needing a keyway or cartridge style lifter. The keyway lifters, are just how they sound and require a key in the bore to hold the lifter from spinning Generally these are found in diameters of 0.937" up to 1.095" with rollers up to 0.940" These must use aftermarket blocks that are designed and machined to use.


Jesel cartridge style key way lifter.









I hope this shows you a little more insight into the little part that could, the lifter.

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#4 Pistons and Rods


A stout engine requires a stout piston and rod combo. When it comes to rods there are a number of choices to be made as to length, material and design.

Connecting Rods

Of course you have design limitations as to the length of the connecting rod because the block is only so big and the stroke is going to factor into just how much room is going to be between the deck height and the crankshaft. With a higher boost engine that is going to produce a lot of cylinder pressure and heat your first concern should be a strong piston which will mean a taller compression height (distance between the crown of the piston and center line of the piston pin). Factor in the stroke, and you will find roughly what your choices are going to be. For std. deck height LS engines rod lengths generally run between 6.036" and 6.125". When dealing with tall deck engines and big stroke crankshafts you might find that the crankshaft company will "cam" the crank for a specific rod or even ask you what you would like it setup for to get the counter weights as close as possible to the correct size and weight.

The next is going to be material. The most common is going to be cast, powdered metal, forged, titanium, or aluminum. Cast rods are almost no longer found in OEM engine designs as they have moved towards the powdered metal versions for strength and a low cost to manufacturer with close tolerances. Most LS and LT engines will come standard with a powdered metal rod that can withstand a good amount of power with no modifications. Titanium has also become a more common stream material even for the OE today. That being said do not confuse the almost powder metal Titanium OE style rods to a high quality race piece. Forged steel rods are still the most common place when it comes to performance upgraded connecting rods. Because so many do make a forged rod, price vs performance on these make them the top choice for almost everyone. Lastly is aluminum rods. Generally speaking these are used for drag racing almost exclusively because of the material will fatigue over time and fail much sooner than a steel rod, and you must account for material growth and shrinking which causes higher than normal bearing clearances. The other issue, is fitting them in the engine. The sheer size of an aluminum rod can pose a lot of issues for the engine builder clearing the block, sleeves, and even camshaft. Below you can see a size comparison between the different materials.



Top to Bottom: Titanium, forged, aluminum


Design is another thing to think about. Most have seen, read, or even purchased an I beam, or H beam forged rod set. You will see debates going back for decades it seems on which is going to be right or better for any one build. From what we have seen, the H beam keeps the big end of the rod a little more stable and shows better bearing wear. Again, clearances inside the engine may force you to one design or the other. Modern metallurgy and designs have made both rods stronger than what most street / weekend racers would ever need.



H and I beam rods side by side. (I beam to the top, H at the bottom)



Now for our build, we are going to be using aluminum because it is light, strong, and less expensive for an engine that is torn down very often, replacing them is not of a concern. This actually maybe one of the lowest cost items in this particular build, at least the first purchase as these can be found for $1000 or less a set, but remember they will need to be replaced.




Here you can see the main components used. Aluminum GRP connecting rods, tool steel Wiseco piston pins, hard anodized Wiseco Pistons, and the aluminum pin buttons (more on those later).


Because aluminum does move around so much with heat and load, you will notice a number of differences when using aluminum rods in your engine. One of the biggest is how the cap is held in place. They will use a large bolt typically, and also the two pieces are split with an interlocking design to keep deflection at a bare minimum.


big end cap design


Another part that changes here, is that the bearings must be held in place with dowels. Again due to material growth, sometimes bearing crush can be an issue so small dowels are placed in the rods, with mating holes in the bearing to keep them from spinning in the housing bores.

Here you can see better of the interlocking design of the cap as well as the bearing dowel.

Bearing dowel in cap.


You will also notice that the small end is much bigger than most, again to cut down on deflection during use and provide more support to the piston pin.


small end


You may have noticed that these are of a slight I beam design, which most billet aluminum rods are going to be, as they only remove material from which it would do the least amount of reduction in strength but most in weight reduction.

Some with a keen eye may have also noticed that there is no bushing in the top of the rod as there would be in a Ti or steel rod. Due to the short life cycle, large clearances, and oiling system used there is no need to have a bronze bushing inserted into the small end of the rods.


Pistons.

Again, like the rods you are going to have a few choices on pistons: Cast, hypereutectic (which is still typically cast), and forged. Again most modern performance cars will almost never use a normal cast aluminum piston anymore and have switched to the hypereutectic design for strength, ease to manufacturer, emissions, and low NVH ( Noise, vibration, and harshness). The Hypereutectic piston contains more silicon than just a normal aluminum alloy casting allowing the builder to spec a tighter piston to wall clearance due to the lower amount of thermal expansion. The one down side to adding the high amounts of silicone is that it will ultimately make the piston more brittle leading to failure in high pressure / high HP uses at the slightest amount of detonation. Almost all OE versions of these pistons are going to be cast, but in a few rare cases they can be produced as a forging as well.


When building a high performance engine, forging is generally the most accepted way to increase strength of the component. Forged pistons are no different, and you will find a couple different kinds on the market today. Most performance forged pistons are going to be 4032 and 2618 alloys.

4032 forged pistons are what you would typically find in your budget kits, or lower cost alternatives. These are much stronger than a cast and in many ways operate like a hypereutectic piston in that they can be ran at a tight piston to bore so noise is decreased but at the same point they can be brittle when pushed hard and suffer similar effects under extreme stresses. For NA engines, or low HP offerings these are typically fine and a step up from cast.

2618 forged alloy pistons will offer a much more ductile material that will deform more so than fall apart under high loads and stress. They can show increased wear over what a hypereutectic or 4032 piston would show in 100k+ miles but advancements in coatings, ring design, and skirt design have proven this almost a non-issue in a modern performance engine build. Anodized ring lands, coated skirts, electrolysis nickel and other coatings can make these pistons last for years even in daily use. You will find many piston companies today like Wiseco, CP, Diamond, and others only offer 2618 in their performance pistons and either not use a 4032 or leave it to the stock replacement pieces only.

In this build we are of course going to be using a 2618 forged piston from Wiseco and for the heat they will be hard anodized to add even more strength to the piston itself. As you might have already noticed from some of the pictures above, this is also a full round piston, meaning the skirt goes completely around the piston for added strength.

One thing that might strike some of you as odd...how the assembly goes together. In most cases the piston pins are either pressed into the assembly or held in with some sort of spiral or wire lock as in a full floating design. Because of the pressure, the heat, and the sheer fact that the engine will need to go through a number of tear downs the only thing holding the pin in place are two small aluminum buttons that sit to either side. These are held in place by the oil support rail and do nothing more than keep the pin centered and away from the bore walls. You can also see just how large the BBC sized tool steel pin is in these pictures as well.




piston, pin, rod, and buttons


piston pin installed


piston pin button


pin button installed


button retained by oil rings



final assembly ready for install



We could go on for pages about the metallurgy with the different pistons and how that effects each dynamic and what coatings are offered for different uses and aspects of racing. The same goes with the connecting rods as well. Which you can see puts a lot of choices on your plate when building an engine. Your engine builder should know which is right for your use, power, and budget. Most will find a quality 2618 forged piston, and H beam rod to be sufficient for most builds out there.

schpenxel

Are the bearing caps machined with those grooves to fit the rod like that or are they fractured? Some OEM's (BMW I know) use a fracturing technique to basically break the cap off in the right spot which yields a perfect fitting cap, which I thought was pretty neat.

Tech

Aren't LS1 rods cracked also?

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The OEM powdered metal rods, are a cracked cap and have been since the start of the LS engines

schpenxel

Interesting, I didn't realize it was that common

Petraszewsky

Those aluminum rods aren't "cracked cap" as they are machined like that

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Correct.

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They are machined as a matched set

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#5 Valvetrain

Because this is going to encompass the valves, rockers, heads, gaskets.....this update is going to have a lot of material thrown at you all at one time. So much of the next steps tie into the next part more so than earlier so bare with us.

The cylinder heads and valve train can sometimes turn into a mystery for a lot of people on their builds. There are a number of steps that you can take to try and cover as many basis as you can if you are trying something new but it does boil down to having a combo that is proven and tested to work together. Picking pieces here and there sometimes can result in very poor performance even though each individual part can be quite good....they just might not work well together.

Some points of this section I will not go into great deal with spec wise as to this particular build.

So off we go..

Camshaft



Camshaft installed


For our purposes within the LS market there are really only two types of camshafts. Solid roller or Hydraulic roller. As you have seen in prior updates on the lifters you already know this is going to be a solid roller profile camshaft. Some of you might know that you can also pick from a traditional style babbitt bearing or go to a roller bearing. You can typically also go larger on the camshaft diameter. In this case we went with the traditional style babbitt but did increase the core size up from 55mm to 60mm to increase the camshaft stiffness due to the pressures it is going to see.





Cam Drive

There are a number of ways the camshaft can be driven and timed to the crankshaft. The most common way for a traditional American V8 has been the timing chain. Of course there are different styles from non adjustable to adjustable, single or dual row chains. There is the every popular gear drive with the hot rodders that love the whine of the gears at speed and almost zero slack in the system. However with high RPM and race use engines, the belt is still one of the best ways to go. These tend to dampen out some harmonics and give an almost shock absorber application when running extremely high spring pressures. Because of the solid roller, high spring pressures, high RPM use and the face that we would like to be able to make adjustments to cam timing....a Jesel belt drive will be used on this engine.



Jesel belt drive front cover

You can see the bolt pattern of the Jesel is exactly the same as any LS front cover so the system can be used on almost any number of LS engine blocks, given you take the time to machine the front of the block for clearance for the cover to fit.

There are quite a number of parts included in the system.

Jesel belt drive

• front cover
• crank drive pulley
• cam adjustable pulley
• belt
• cam plate with thrust bearing
• hardware

The front cover bolts in using a o-ring seal to the block (after the block has been machined). You may notice the large hole in it, the cam retainer plate is o-ring sealed to this and bolted directly to the cam with the traditional three bolts. Now what makes this nice is that cam swaps can be done without pulling the entire front cover off. The cam pulley is then held on with one very large left hand nut, with the pulley slotted to allow for cam timing adjustments without tearing the front cover off the engine.



Below you will see the final assembly installed waiting on the balancer.





Belt drive installed along with ATI drive hub


Now you might be asking why not run a belt all of the time? Well they do stretch over time and will have to be serviced. In this case they are exposed to the elements so street use where rocks and debris can damage the belt and pulleys would not make it the best choice for a daily driver. For most builds out there, a chain is still the best of both worlds. The other piece to notice when applying this to an LS engine, there is zero room for an "internal" oil pump. When using the Jesel the engine must be a dry sump oiling system.

Timing is very critical on not only degreeing in the cam but also the balancer. Before the driver side head is placed onto the engine, we must make sure the timing marks on the balancer are correct and that we have the cam timing that we would like to see and locked in.






Cylinder Heads

Here we could devote an entire book on, so we are not going to go into who's head is better than who's or the details of head porting. Cylinder heads in many ways are one key item in to knowing how much an engine will make, at least NA wise. The size of the intake valve, the intake runner size, and how much CFM it can actually flow will give you a good idea of what the potential of the engine is. Air flow velocity must also be taken into account along with the total air flow. This one is slightly different in that we are force feeding it, but never the less, the heads have to be able to flow air. So lets look at a few key components that make this one different. The heads we are using in this build are a 6 bolt GM LSx DR head ported and worked over by Greg Good with final assembly done here in house.



Bronze intake guide, steel exhaust guide


Because this engine is going to be forced induction, and a turbo at that, there is going to be a lot of exhaust heat in the head. A bronze guide will just not hold up to very high EGT's so in this case a steel valve guide is used. You will also notice a really small o-ring...that is pretty much the only valve seal that will be used. Since the engine will never see street use and will be torn down for rebuilds more often than your street car, the traditional seals are left off. This also allows slightly more oil to keep the valves lubed and cooled.


Both the intake and exhaust valves are made from solid Titanium and are longer than normal to accept the big springs and adjustable rocker arms that will be used.

Ti intake valve


Ti exhaust valve


For an idea of size

Intake valve


intake port


exhaust port


To keep the valves under control we are using a triple valve spring from PSI. High RPM, high boost, and a solid roller cam is going to require a higher than "normal" performance valve spring. Seat pressure on these springs is a little over 450 lbs which is more open pressure than what you will find in a common place hyd cam kit for your street car. Open pressures can exceed 1200 lbs and the springs are able to support over 1" of lift without coil bind issues. Here you can see them apart compared to a popular dual spring package commonly sold online. These are required for the extreme lift, rpm, and boost even when using a very light valve as we have shown above.


Assembled springs


Springs apart


Big springs....require big spring compressors as well.







Once the heads are cleaned, springs setup for height, they are assembled and will be installed.

Head gaskets are solid copper with a o-ring wire in the head, and receiver groove in the block surface. Because of this, we will install each head and torque to spec and let it sit over night to emboss the groves into the gasket. Each gasket is then marked, and removed until time to be installed for good.


Head gasket waiting to be embossed


First head going on


You might notice that #1 has checking springs on it. Since we will have to remove the head after this procedure we are going to take this time to accurately measure piston to valve clearance to make sure all beginning calculations were right and we will not have any interference issues. We are also going to take this time to check for accurate pushrod measurements. Since we left the lifters in the block for #1 we are going to mock up the entire valve train for this cylinder and rotate the engine to make sure the pushrod length is correct and within the adjustment of the rocker arms.

Once the head has been removed, the lifters are cleaned, and oiled before installing into the block for good.

Lifters going in






Once the lifters are installed, and the gaskets embossed we take to bolting the heads down for the final time.


Cylinder head install for final time


Rocker arm assembly time

Since we had taken the time to measure the pushods during the head gasket seating procedure they arrived without much delay in doing assembly for the final time. We checked for not only the correct length but also for the correct diameter. Again, due to the extreme valve spring loads, using a strong pushrod to fight against deflection in the valve train is very important. Intake and exhaust lengths are different as in most engines of this caliber, but we also strive to use a much larger diameter than most might think of. These are a dual taper 1/2" to 7/16" with dual tool steel tips to make sure they clear all components involved.


Custom double taper pushrods with tool steel tips on both ends.


Compared to a "beefy" stock LS7 3/8 pushrod



The pushrods will be operating a set of adjustable Jesel shaft mounted rocker arms setup for the LSx DR cylinder heads.


Aluminum 1.8 ratio intake rocker arm

Steel 1.8 ratio exhaust rocker arm


You are going to be quick to notice that those two arms do not look the same....and they are not. There are two main reasons we chose to run a dual style rocker. Cost and weight. Because the loads on the intake rocker arm will not be nearly as high as the exhaust, which is opening against high cylinder pressure, we can run a lighter aluminum bodied arm. The aluminum arms also reduce cost vs running steel arms on both intake and exhaust side.

Prior to install, each rocker is inspected, cleaned, and oiled at all pivot points. Assembly lube placed at both ends of the pushrods and at the bottom cup of the adjuster on the rocker so nothing is dry on start up.


Rocker arms installed, ready for lash


Here you can get a good idea of just how much these rockers are going to have to move. You will also notice how much you need to take care of your clearances, as some are very tight, as in the intake rocker to pushrod.


exhaust at full lift

intake at full lift.


Once all are installed we will spin the engine over by hand a few times and remove a couple rockers to check for a wear pattern on the tops of the valves.


Wear pattern right in the middle, even with over 0.9xx of lift





While we did not go into detail on the cam specs, RPM range, head flow numbers....all of these are important to work together. Doing your math prior to ordering parts is a good way to get started but testing is the only real proven way to know for sure you are not going to have issues with your build. This in many ways is why it is very important to work with your engine builder on your project so both parties know exactly how the engine is going to be used, what should be expected of it both in performance and maintenance schedules. Pick and engine builder that will be honest with you and not tell you what you want to hear but what is right. Picking a good engine builder from the start should go without saying....


This one might create a number of questions that I didn't cover so fire away!

KSA Aaron

Awesome tech! Keep the updates coming.

0HP RESEARCH

#6 Supporting Hardware


This might be the last update for a few months as the engine has left our facility and is in the hands of the car builder to finish out the plumbing, install, turbo kit, fuel system and other pieces.

The one thing at the start of this series I did not state was the fact that it will be a alcohol fueled engine so the HP rating of 2000+ is more along the lines of 3100-3600 hp, possibly more depending on final boost levels, and fuel mixture. Hopefully I will be able to share some pictures of the car and maybe a video down the track once it is all done and tested.

For now, I will leave you with these final pieces


Stef's custom one off LSNext dry sump oil pan. First one ever made.







Peterson dry sump oil pump







front side of the fuel pump....notice the fitting size


Fuel pump assembly





Yes you are reading that correctly, 700 lb/hr injectors



Intake manifold, rails, and TB's


Nice sized pair of TB's


Side shot




So, that should give you a quick look inside what is going on inside a big HP build. The parts you do not see is the time it takes to assemble something like this. Unlike most normal street and hot rod engines these typically will have to be assembled, a couple times during the build and torn back down as some parts may interfere with others requiring machine work, and re-cleaning before going together.


Now it is up to the car builder to finish up the accessories and install.

RGT

I really enjoyed reading this thread. Good stuff.

Petraszewsky

What about using a steel guide with replaceable bronze liner for the exhaust valve? Plus the bronze would play a little nicer with titanium.

inspector12

Nice read lots of stuff you mentioned that a lot of ppl I talk to don't know or understand so its nice to see someone take the time to talk about it a thread at detail