photos by: Scoggin-Dickey Parts Center and the author

Building a Boosted, Forged 416 Cubic-Inch LS3 for the Track

In the last several weeks, many of our readers and social media followers have been jaw-dropping with all of our updates to our 1984 Trans Am project, that we affectionally call, Project Redrum. Built primarily for autocross action, with 100% street capabilities, every square inch of the car that’s intended to make the car stop, go, turn, corner and essentially put a smile on your face will ultimately result in getting replaced or rebuilt.

The overall rat rod aesthetics will remain, although with a forged 416ci. LS3 nestled between the fenders and a Magnuson supercharger to boot, we’re fairly confident that this thing will absolutely fly! However, we’re not interested in a numbers car, what we want is something that will provide a perfect balance in all aspect of its build, with the “wow factor” being a byproduct. That all starts with a solid foundation of high-quality parts, and of course, a competent crew to build it! After all, what’s the point of selecting the perfect recipe of hardware of you don’t have the talent as a part of the process?

Since we’re lucky to work among the best in the business, we decided to enlist our friends at Scoggin-Dickey Parts Center to craft the perfect weapon; using off-the shelf components from Brian Tooley Racing, Chevrolet Performance, Manley, ARP, Total Seal, Callies, Clevite, Holley Performance and Dura-Bond. We also installed a set of CNC-ported Blueprint Racing Engine LS3 cylinder heads, but more on that in a minute.

Having built engines for various street/strip machines and corner carvers for quite some time, SDPC has expanded their engine-building capabilities, courtesy of their recently constructed SDPC Raceshop. The SDPC Raceshop has the capability to provide blueprinting, balancing, port work and a complete cylinder head shop. A Superflow engine dyno, 1020 air flow bench, a Rottler computer-controlled vertical hone and much more make the SDPC Raceshop one of the fastest-growing machine shops in the country. There are plenty of off-the-shelf options available for various types of customers. We worked directly with Keith Wilson and Brian Gruben at SDPC, who suggested the 416ci. LS3 — with the 10cc forged dished pistons and 10.5:1 compression ratio for our specific build.

We’ve compiled a short list of components below, that filled our LS3 short-block built for reliable performance, high horsepower and plenty of boost. We also included the part numbers and price for each component, for reference.

Forged 416 ci. LS3 Long-Block: The Hard Parts

• SDPC 416ci. Short Block Assembly (PN-341610CSCHMF): $5,349.87
• SDPC LS Trunnion Kit (PN-SD1370): $179.99
• SDPC Ported, Blueprinted High-Volume LS Oil Pump (PN-SD3964B): $149.75
• SD7650 LS Dual Valve Spring Kit: $259.87
• X10166345 Valve Loc x32 $1.80
• X12595365 Guide x4 $10.00
• X12595365 58x S/Row $95.40
• Manley Stainless Steel Intake Valves (PN-MAN11620, x8): $26.72
• Manley Stainless Steel Exhaust Valves (PN-MAN11621, x8): $26.72
• Manley Chromoly Swedged End Pushrods (PN-MAN25735, x16): $14.00
• ARP HD LS-style Cylinder Head Bolts (PN-ARP1343610): $216.35
• Chevrolet Performance Timing Cover Bolts (PN-11515758, x4): $1.17
• Chevrolet Performance Camshaft Bolts (PN-11561455, x4): $4.40
• Chevrolet Performance Rocker Arms (Intake, PN-12569167, x8): $14.77
• Chevrolet Performance Rocker Arms (Exhaust, PN-10214664, x8): $15.25
• Chevrolet Performance Rocker Arm Bolts (PN-12560961, x16): $5.66
• Chevrolet Performance LS Camshaft Retainer (PN-12589016): $24.50
• Chevrolet Performance Rocker Arm Support Stand (PN-12600936, x2): $9.86
• Chevrolet Performance Lifter Guide Retainer Bolts (PN-12551163, x4): $2.83
• SDPC Timing Chain Dampener (PN-SDG88670) $20.21
• ARP LS Camshaft Bolts (PN-ARP1341003): $12.17
• SDL408560 x2 $123
• Scoggin-Dickey LS Engine Storage Cradle (PN-SDCRADLERED): $42.95
• Labor: $920.00

Choosing the Right Camshaft

That’s the entire list of hardware found in our SDPC forged 416ci. short-block. Chief among which, is the Brian Tooley PDS Stage III camshaft. Designed solely for boost, particularly 6.2L LS engines with a supercharger, it had even been the choice of bumpstick for our friend, Howard Tanner at Redline Motorsports, when he set the ZL1 cam-only record.

Spec’ing in at 231/248 .617″/.595″ 120+5 and comes a 3-bolt timing gear pattern, it’s certainly on the higher-end of the aggressive scale. When we spoke with Brian at BTR, we initially had been a little baffled of which camshaft to choose. There are so many options on his site, that even the experienced LS builder can feel a little overwhelmed but Brian was gracious enough to take the time out of his day to recommend this cam for Redrum.

We ordered up the BTR PDS Stage II blower cam for our particular build. Quickly becoming the choice in camshaft for many tuners and engine builders, the PDS Stage III is the now go-to for positive displacement blown 6.2L+ LS engines. Mr. Tooley recommended this for our build, personally. Retail: $399.00

With almost 0-degrees of overlap it has a definite camshaft sound, but still has a mild idle, yet makes the power of much larger cams. As Brian tells us, the secret is in minimizing the overlap, while maximizing the intake valve closing and exhaust valve opening events. This cam has proven to make more power than other cams that have more lift, which makes this cam much more durable. He also related that, if the lift is approaching .650″ or more while using stock 15-degree rocker arms with too much open spring pressure, it can damage the valve tips in the long-term. BTR recommends maximum lift of .630″ and maximum open pressure of 400-lbs. when using stock rocker arms.

Cylinder Heads and Valvetrain

The choices we could have gone with are endless. Obviously, with the idea of big cubes, boost and a high-loft (for a boosted application) camshaft forcing oxygen in and out of the engine, we wanted cylinder heads that benefit the rest of our build. BluePrint Engines answered the call with their PS8015 LS3 cylinder head castings. Designed to offer enthusiasts huge power numbers with an affordable outlay, the flow numbers and attributes of the PS8015s are impressive.

These lightweight aluminum heads bolt up to your LS engine and feature 259cc intake/102cc exhaust ports, 72cc combustion chambers, and 2.165″ intake/1.600″ exhaust valves. They’re fully assembled with heavy-duty valvesprings, retainers, locks, guideplates, studs, and seals — if you order them assembled. We ordered ours bare, since our build was a very unique build.

We’ve listed the complete specs for the BPE heads below.

Sitting on top of our forged 416 LS3, are a set of these CNC-ported, high-flowing BluePoint cylinder heads. They fall under BPE Part Number PS8015. You can order them bare, like we did in our case, or fully-assembled directly from BPE.

 

Long-Block Assembly:

With the Callies crank in place, the next step was to check the thrust without the rear main cap on. A dial indicator was placed at the front of the crankshaft and set to zero (0). Next we gently placed a flat-head screwdriver between the counterweight and the main, and applied some tension back and forth for a reading. Generally, on performance applications you’ll want no less than 0.006 inch. High-boosted applications or extreme clutchless-type race cars will demand more clearance. SDPC Raceshop takes incredible care and attention-to-detail to every engine that they assemble.

As we’ve mentioned before, our friend at SDPC Raceshop already had all of the necessary hardware in stock and ready for assembly. What we did on our end, was ship the Brian Tooley camshaft, BluePrint cylinder heads, Holley oil pan, pickup tube and valve covers to our friends at Scoggin-Dickey. We wanted all of our components to compliment each other, in both the assembly process and in regards to the components that were selected.

When we were sent sneak peek shots like the one above, via e-amil, we immediately began to get excited. The crank, connecting rods, mains, pistons — the entire short block — was already assembled and ready long-block assembly.

The BluePrint CNC-ported LS3 heads and Brian Tooley valvetrain in their ready-to-install state. It’s always a great idea to double-check the spring rate of the springs, as well as examine the heads for any burring, rough edges or warping before installing. With everything checking out perfectly, the next step was installation.

 

When we were checking our piston-to-valve clearance, we once again enlisted the help of our dial indicator. For the dial indicator method, use solid lifters, install the rocker arms and set zero lash. Rotate the crankshaft clockwise until the degree wheel indicates the Number-1 piston is at 10 degrees ATDC on the intake stroke. This is the crank angle where interference is most likely to happen–not at TDC or at maximum intake-valve lift. At this point, the piston on its way down and, depending on the cam lobe profile, the intake valve is trying to chase it down. Mount the dial indicator on the cylinder head and position it over the retainer of Number-1 intake valve. Set the dial indicator to zero. Make sure that the plunger on the dial indicator has plenty of range to move up and down. Use a small screwdriver or pick to push tip of the rocker arm downward until you feel the valve contact the piston. Observe the dial indicator to determine the actual piston to valve clearance. To measure the clearance on the exhaust valve, rotate the motor clockwise until the timing wheel is at 10-degrees BTDC on the exhaust stroke. Again, this is the crankshaft position most likely to see piston-to-valve interference as the piston moves up and draws a bead

 

We had our friends at SDPC Parts Center install the cam and crank sensor, valley cover and front and rear engine covers. This was the completed long-block, just before it was sent over to be shipped out. Our work is just getting started, as we still have plenty of components to install before we can think about firing this thing up!

Rounding out the Details:

With such incredibly impressive hardware as our forged foundation, we wanted (and needed) the right components to bring the whole package home. Holley Performance answered the call when we went looking for valve covers and oil pan, with Chevrolet Performance front and rear engine and valley covers. We didn’t feel a need to get fancy with the ring e covers, but we certainly needed an oil pan that would work for our LS-swapped third-gens, as well as valve covers that provided a bit more attitude to our engine bay.

We wanted to give our Firebird’s engine bay a unique look, and take a different approach to our choice of valve covers. During last year’s SEMA show, we got an eyeful of Holley’s tall Dominator LS Valve Covers with a black satin finish. They fall under part number 241-120 in the Holley catalog, and provide additional room for for larger rocker arms.

 

Another interesting keynote of the Holley Dominator valve covers is the billet aluminum oil cap. It’s a slick-looking piece that blends well with the valve covers, and also adds a touch of “bling” to the engine bay. Its will compliment our upcoming Concept One pulley system, that you’ll be reading about as well in a future installment. You’ll also notice the QTP engine lift plate, that we’ll be taking a closer look at in the next installment.

Features:

• Eliminates the coil-on-cover look and instead feature bold graphics with “Dominator” logo
• Eliminates unsightly OE style coil brackets
• Billet aluminum oil fill cap
• Reuses original gaskets and bolts
• Designed to fit GM LS1, LS2, LS3, LS6 and LS7 engines
• Designed to add an additional 0.54″ if of internal clearance over factory height valve covers
• Lengthened factory style mounting hardware
• Holley’s LS covers use proven OE style baffles and vents
• Also available in gloss red, polished and natural cast finishes

With a total oil capacity of 6.2 quarts with stock oil filter, the Holley LS Retro-Fit oil pan requires the use of a GM LS3 dipstick (GM P/N 12634547) and tube (GM P/N 12625031). According to our friends at Holley, the engine location may need to be adjusted for cross member or steering linkage clearance depending on the vehicle, steering configuration and chassis type. This particular oil pan 302-2 is designed to use a GM “F-body” windage tray, GM P/N 12558253. A modification to the windage tray is required to provide clearance to the pick-up tube (included). A full-length windage tray may be used if the front quarter of the tray is removed.

 

The Holley Performance oil pan looks right at home bolted up to our 416, and is designed to work with most LS swapped vehicles for clearance issues, including ’82-92 Camaro/Firebird. It also works well with LS-swapped ’78-88 G-bodies, too! The engine stand that our long-block sits on, showed up bolted to the LS3 block, and fastened down to the wooden cate that SDPC had shipped our engine in.

Features:

• Designed for LS engine retrofit installations in GM muscle/classic car and truck chassis requiring more oil pan to chassis clearance around the front half of the oil pan.
• Perfect for: 1967-69 Camaro/Firebird, 1968-74 Nova/Apollo/Ventura/Omega, 1982-92 F-body, 1978-87 G-body, and 1964-72 A-body applications.
• NOTE – Oil pan #302-2 may not be used with LS7 engines or “stroker” engines greater than 3.62”.
• Can be used anywhere a GM F-Body oil pan can be used
• New applications will be added as testing confirms fitment
• Provides OEM fitment – OEM oil filter mounting, OEM oil cooler port provision, OEM engine NVH suppression, OEM flange gasket and sealing, proper structural rigidity and OEM bell-housing attachments.
• Traditional high-quality cast aluminum appearance with clean exterior styling.
• Provides maximum clearance for vehicles where the steering linkage is behind the engine crossmember.
• Cast and machined aluminum
• Complete kit includes sump baffle, OE style pick-up tube, sump plug, oil filter stud, oil passage cover, etc.

Part of the SDPC package included several quarts of Driven’s BR30 break-in oil. A conventional blend, weighing in at 5w30 and designed specifically for freshly-assembled engines that require a high-level of zinc, it’s the perfect formula that’s highly-recommended by many in the industry, including SDPC Raceshop.

With our long-block assembly assembled and ready to install into Project Redrum, be sure to tune in for the install story in the next segment, where we’ll be dropping the 416 into the engine bay! We’ll also be connecting this engine to an American Powertrain 6-speed and Strange S60 rearend! So you don’t want to miss it.

Rick Seitz

Rick Seitz is the owner and founder of GMEFI Magazine, and has a true love and passion for all vehicles. When he isn’t tuning, testing, or competing with the brand’s current crop of project vehicles, he’s busy tinkering and planning the next modifications for his own cars.