What’s It Take To Run 6.16 In A Street Truck? Look Inside The ProLine Racing Engine That Propelled Larson On Drag Week 2014

What’s It Take To Run 6.16 In A Street Truck? Look Inside The ProLine Racing Engine That Propelled Larson On Drag Week 2014

When Larry Larson and I decided we were going after a 6th Hot Rod Drag Week Title for him in 2014, we also wanted to be the quickest and fastest street car in history. And while Andy Frost’s 6.4 second record was impressive, our goal all along was to run 5.9 seconds. In order to do that, we needed light weight and big power. Here is an overview of how we got the power.

At PRI, Larry and I talked to the guys at Brodix about a 5.0 bore space PB5000 combination, and started initial discussions about the build with Larson’s long time engine builder Mike Moran. Moran clearly knows how to build power, but later conversations, sponsor support, and several weekends at Pro Mod races got us talking to Eric Dillard and Steve Petty at ProLine Racing Engines. Once they heard our plans, ProLine jumped at the chance to be a part of this adventure and the ball was officially rolling.

ProLine Racing Engines has built several PB5000 combos, and were familiar with the platform, but for those of you who may not be, here’s the dirt. A stock big block Chevrolet has a bore spacing of 4.840 inches, center to center. A few years ago racers figured out that if you spread that bore you can not only increase overall bore size for more cubic inches, but also spread the intake and exhaust ports on the cylinder head for a better flowing head design. Soon racers were building 5.0 inch bore space combos, and then they began pushing the limits even further. The current 5.3 inch bore spacing combos are the norm in Pro Mod and allow big cubic inches for Nitrous guys, and/or increased head sealing surface for blower and turbo combos.


While we were perfectly thrilled with the idea of a 5.3 inch bore space combination in the truck, the budget would not allow it, and more importantly the blocks available have no provisions for water inside them for cooling. Clearly this wouldn’t work with Drag Week’s 300 plus mile daily drives, and a custom wet billet block would have cost even more money. 5.0 inch bore space it was! Of course, ProLine also added some of their proven updates and upgrades to make sure that this ProLine Racing Engine could make the entire trip, without sacrificing any power.

Here are the parts and pieces for our ProLine Racing Brodix PB5000 combo that powered Larson to 6.16 seconds in the quarter mile. More details are below.

620 cubic inches
Brodix PB5000 Block and Heads
Callies Ultra Billet 4.500 inch stroke Crankshaft
GRP Connecting Rods
Diamond Anodized 4.680 inch bore Billet Pistons 10.6:1 Compression
Innovators West Dampener
Total Seal Rings
ARP 625 Stainless Steel Head Studs
ARP Fasteners throughout
ProLine Racing Custom Steel Exhaust Guides with Bronze Liners
PAC Racing Valvesprings and Titanium Retainers
Victory Titanium Intake and Lightened Steel Exhaust Valves
Crane Billet Tool Steel Camshaft with .800 Lift
Jesel 1″ Raised Cam Belt Drive
Jesel 1.6 ratio Rockers and Keyway Lifters
Smith Brothers Pushrods
Hogan’s Racing Fabricated Intake Manifold
Dual Accufab 4″ Throttle Bodies
Precision Gen 2 98mm Turbos, Wastegates and Blowoff Valves
Precision Turbo 220lb and 550lb fuel injectors
SCE Gaskets
Peterson Fluid Systems 6 Stage Dry Sump Oil Pump, Tank, And Primer/Filter Assembly
System 1 Oil and Alcohol Filtration
Aeromotive Belt Drive Alcohol Fuel Pump with Custom Drive for Peterson Dry Sump Pump
Aeromotive Dual Phantom Fuel Pump for Gasoline on road driving, Aeromotive Filtration
Fragola Hoses and Fittings for Fuel System, Cooling, and Oil Lines
Jiffy-tite Fittings for Fuel and Cooling Lines that were switched during the change from street to strip
PowerMaster alternator
Fuel Tech Fuel Injection Engine Management
MSD Distributor, Grid, Boost Control, Coil, Wires, Etc.

Once all the parts were acquired, and had been delivered to the guys at ProLine, Kerry and Chris managed the parts and process of getting this beast assembled and ready to race. But it wasn’t that simple. ProLine has some specific things that they do to a Brodix PB5000 combo prior to assembly, including steel exhaust valve guides with bronze liners, dry decking the block and heads, and maximizing crankshaft longevity with a Torrington thrust bearing.


The task of getting the heads ready for assembly was given to Jonathan, who spec’d the steel valve guides first thing. This modification by ProLine has been proven to not only increase the life span of the exhaust valve guides, but also keeps the valve stem more stable under the extreme conditions that ProMod style engines experience. The steel guide is installed much like a standard Bronze guide, but is lined with a .015 wall thickness bronze liner for lubrication. Not only does the steel guide live much better under the extreme temperatures seen in the exhaust port of a turbo engine, but they also offer increase strength and stability should a piston and valve come in contact with each other. In this type of scenario, the steel guide will hold up to the forces of the bending valve and tends to limit damage in comparison to a traditional bronze guide. The thing bronze liner then becomes and easily serviceable part once it has reached the end of it’s life cycle, which surprisingly is longer than the traditional bronze guide would be. Inside those steel guides are Victory Titanium and Stainless valves, which are held in place by PAC Racing Springs and Retainers. We chose Stainless exhaust valves rather than Titanium because the increase heat during the driving portions of Drag Week may have caused premature wear on Titanium valves. Instead Victory lightened up their Stainless valves, without sacrficing strength, and the result is a valve that works well with our combination of camshaft, lifters, and rockers.

After the steel guides were installed and fitted, the next step was to weld up the coolant passage holes in the deck of the cylinder heads. (You’ll note in the photo above that the coolant holes are still in the deck, but have hex head plugs installed in them. The photo of the Block below shows that the holes have been welded shut and then the deck resurfaced.) The corresponding holes in the block would also be filled. ProLine’s thought process here is to keep water from being at the deck in the event that a head lifts at extreme boost levels of 50psi or more. Because water can no longer flow through the head and into the block through the traditional cooling passages, external lines were built that send water between the heads and block to allow proper cooling. Despite ProLine’s assurance that the engine would stay cool with this modification, Larry and I were skeptical. It turns out they knew exactly what they were talking about as we only saw engine temps above 200 on one leg of the trip when we lost an alternator belt and our cooling system wasn’t able to run at full capacity on battery power alone.


While Jonathan was getting the heads ready, Brad got the block ready for assembly by filling the aforementioned coolant passage holes in the deck and prepping our block for some very special ARP 625 Head Studs. These stainless head studs are made from the finest fastener material available today, thanks to a special alloy created with the foundry and ARP. There is literally nothing available with today’s metallurgy technology that would make a better head stud fastener. Because we were pushing this engine to such extremes, it was determined that drilling our block for larger 1/2 inch studs would in fact weaken the deck, so we needed the best 7/16 inch studs on the planet. ARP delivered. Although they are smaller than ARP’s L19 1/2 stud that would normally have been chosen for an application like this, the 625 studs are within a couple percent of the larger studs in overall strength. This strength comes at a price, but if you are looking for the baddest head studs on earth, call ARP and ask for the 625s.

While Brad was at it, he also setup the block for a Torrington thrust bearing which gives the crankshaft and bottom end more durability with the extreme shock loads experienced during the launch of these types of cars. Of course thorough cleaning, thread chasing, de-burring, valley oil return screens, and blueprinting are all part of the block prep process, and were handled by Brad before he passed the block on to Joey for final assembly.


Once Joey received the block and heads from Brad and Jonathan, it was time for more parts from Kerry. With a cart full of stuff, Joey started assembly using all the parts mentioned above. Like any engine, cleanliness is the key. It never hurts to wash things one last time before assembly, as any piece of debris can cause problems upon startup. Thanks to precise machine work, blueprinting, and mockup assemblies by the gang at ProLine, Joey’s final assembly is pretty straight forward, but does require an eye for details. Piston ring gaps and placement are key to proper combustion and oil control, which is why ProLine only uses Total Seal rings. We experience almost no blow by on Drag Week, despite running our engine on both Gasoline and Alcohol.


One thing you’ll note is the green color of our Diamond Pistons. This is not a coating like you would normally think of in an engine. This is hard anodizing. ProLine uses hard anodizing, rather than dry film coatings, to protect the pistons, cylinder walls, etc. Hard anodizing is used because ProLine has found it to be more efficient at maintaining dimensional stability of the pistons. With hard anodizing, they have found that the piston is less likely to grab and gall, particularly when the skirt has been distorted due to abuse and is starting to contact the cylinder wall more than normal. Anodized pistons have become a regular practice at ProLine Racing just to make sure that no customer has an issue with wear. Diamond of course put together our pistons with the appropriate valve reliefs, pin height, dome thickness for boost, etc, and can do the same for you regardless of the power level you are reaching for. And as “trick” as some people will think our combo is, our pistons are basically an off the shelf part for Diamond, like the jillions of other combos they have available. But if you do have something weird, they can most certainly help you out with that too.


The Diamond Pistons hang off a set of GRP BBC 5550 Aluminum Connecting Rods that as Woody at GRP said are ” a big block Chevy rod on steriods.” They feature meat in all the right places for extra strength, are 6.800 long, and the 2.325 big end is sized for a 2.200 rod journal size on the crankshaft. That’s standard big block dimensions, and keeping the big end round are ARP L19 7/16 inch rod bolts. These rods weigh 744 grams each, which is lighter than a heavy duty big block steel rod, but not by a ton. Where this rod excels is in the fact that it is lighter weight with much more strength in critical areas. And to insure the strength is carried over to the piston end, GRP outfitted our rods with 1.094 Hemi pins that are secured with Diamond’s button retainers.


Our Callies Ultra Billet crankshaft is pretty standard, for a billet crankshaft, and features all the lightweight tricks and strength enhancements you expect from a crankshaft of this caliber. They are available for a variety of applications, and are available in multiple bore spacing combinations for Big Block Chevrolets like ours. Various rod journal diameters are available as well, and you can choose between 6 and 8 counterweight models. We went for the 8 in our combination as the high load turbo combos like them better. Profiled counterweights that are designed to shed oil quickly, work in conjunction with our Peterson Fluid Systems dry sump system to keep oil off the crank where it can rob horsepower. Ultimately a crankshaft seems like a big dumb chunk of metal, but the guys at Callies make them into a work of art that can not only survive at the 3000+ horsepower level, but actually make power due to balancing and oil control. Duane and the guys there did a great job for us, and we are working on some cool tech about crankshafts that will help you guys whether your combination makes 500 or 3500 horsepower.

One thing we want to stress is the fact that this engine is a ProLine Racing Engine. It’s not a compromised street engine that we put a ton of boost in and hoped would run the number. With two exceptions, it’s the same as any ProLine PB5000 race engine combo.


Because valvetrain is a concern on engines like this running at a sustained RPM, while driving down the highway on Drag Week for instance, we put serious thought into the camshaft’s total lift and duration, as well as rocker arm ratios. Chase Knight at Crane helped the guys at ProLine spec our .800 inch lift camshaft, which is approximately .100 to .150 inch smaller than what might be the extreme you would run in this engine combo. In addition, instead of a 1.7 or 1.8 rocker arm ratio, we went with a 1.6 ratio on our Jesel rockers in order to save wear and tear and strain on the rocker arm assemblies. Jesel and ProLine worked closely together to determing the ideal ratio for our application, and keeping overall cam lift lower, and the rocker arm ratio lower, keeps every valvetrain component happier. The Jesel keyway Roller Lifters are traveling less distance both around the lobe and up and down in the lifter bore, which means that roller speed and lifter speed are both reduced at any given engine speed. This helps bearings and lubricated surfaces live longer. That’s a good thing on Drag Week.


In addition to limiting camshaft and valvetrain, ProLine also lowered the compression slightly on this particular engine. Normally a gasoline fueled turbo combo like this would have approximately 9.25:1 compression. A normal alcohol burning combination like this would have approximately 11-11.5:1 compression. Because we are driving ours on the street on gas with no boost, and on the track on alcohol with plenty of boost, the guys at ProLine decided to compromise slightly by lowering the compression to 10.6:1. This gave us a slightly larger tuning window on alcohol, provided plenty of compression and power for driving down the road with the trailer under no boost, and the increase in compression over a normal gasoline combination also made it run cleaner on the highway without loading plugs and being finicky about timing.

Our camshaft choice was determined not only by ProLine’s great relationship with Crane, but also by their continued support here at BangShift. They build great camshafts, and Chase Knight is probably one of the sharpest camshaft gurus in the business. While details on duration, overlap, centerline, etc are not included here, suffice it to say that all the specs are just slightly more mellow than your typical race combination. Given the fact that we are force feeding this combo with a set of Precision Gen2 98mm Turbos, we weren’t worried about power potential and Chase’s recommendations were aimed at starting a bulletproof valvetrain with a camshaft that would treat all the other components well. And while .800 lift may seem like a lot for a small block or something, it’s relatively small on a 620 cubic inch engine. Duration was also kept in check as we aimed for a combo that would make peak power and ensure the valvetrain stayed alive by keeping RPMs at or below the 9000 rpm mark.


The Hogan’s Racing Manifold was custom built to house two sets of Precision Turbo injectors, dual Accufab 4″ throttle bodies, and a burst panel out back in case things got ugly. The rails and much of the intake are billet, and it’s one sexy piece. Out front those dual Accufab throttle bodies control the incoming air charge from the Precision Turbos and their Ford TPS makes communicating with the FuelTech ECU a breeze. Surprisingly, the throttle response and driveability of this combo was excellent despite having this much throttle body hanging up front. Throttle modulation was not a big deal at all, as this thing drove like a 3500 horsepower rental on the street.

Drag Week 2014 Larry Larson Plans S10 Pro Mod 012

Controlling all the fuel, and ignition timing, was FuelTech’s new FT500 engine management system. We are going to go into more detail on this cool new system in another story, but here are the details you’ll care about right now. This new FT500 system was designed in collaboration with FuelTech and ProLine Racing. Steve Petty was instrumental in the development of this new system, and it is designed to be used on anything from a Jet Ski to a Pro Mod car. One of the coolest things about it for us on Drag Week was the fact that the touch screen IS the entire ECU, which made on road tuning or adjustments a breeze. And, because we were running on Alcohol at the track and Gasoline on the street, the fact that the FT500 stores multiple tunes was a great feature. We literally could change from our Gasoline tune to our Alcohol tune in a matter of seconds. This means that users of this system can have street and race trim at their fingertips. We dig that for sure. If you prefer to see a large 3D map or table of ignition and fuel, you can tune this system by plugging in your laptop to the usb cable as well. It will do it all. External injector drivers mean that our “small” 220lb Precision injectors ran on 4 amp injector drivers and our “big” 550lb injectors ran on 8 amp drivers. We were one of the first cars in the country running this new system, and are excited about it’s potential. New universal harnesses, increased features, and more are on the way, and we’ll have a full rundown on the entire lineup of FuelTech parts coming soon, including details on how we integrated it with our MSD Grid, Boost Control, Etc.

FuelTechFT500 1

There are a lot more details to the engine that powered Larson to a 6.16 second pass on Drag Week, and we’ll get into those specifics as we cover a lot of tech stories on different components in the coming weeks. Stay tuned for great information on Pistons, Connecting Rods, Crankshafts, Camshafts, Valvetrain, EFI, Drivetrain components, suspension, and much much more.

Also stay tuned for Chad’s recap of the week coming tomorrow hear on BangShift.com.

And to answer your question as to whether or no we’ll run 5’s with it this year? We’re sure as hell going to try! Stay tuned for where we’ll be racing it more this year.


Brodix PB5000 Block and Heads  Brodix.com
Callies Ultra Billet 4.500 inch stroke Crankshaft  Callies.com
GRP Connecting Rods  GRPConRods.com
Diamond Anodized 4.680 inch bore Billet Pistons DiamondRacing.net
Innovators West Harmonic Balancer  InnovatorsWest.com
Total Seal Rings  TotalSeal.com
ARP 625 Studs and Fasteners  ARP-Bolts.com
PAC Racing Valvesprings and Titanium Retainers  RacingSprings.com
Crane Billet Camshaft  CraneCams.com
Jesel Belt Drive, Lifters, Rocker Arms   Jesel.com
Smith Brothers Pushrods  Pushrods.net
Hogan’s Racing Fabricated Intake Manifold  HogansRacingManifolds.com
Dual Accufab 4″ Throttle Bodies  AccufabRacing.com
Precision Gen 2 98mm Turbos, Wastegates and Blowoff Valves, and Injectors   PrecisionTurbo.net
SCE Gaskets  SCEGaskets.com
Peterson Fluid Systems Dry Sump System  PetersonFluidSys.com
System 1 Oil and Alcohol Filtration   System1Filters.com
Aeromotive Fuel Pumps  Aeromotiveinc.com
Fragola Hoses and Fittings   FragolaPerformanceSystems.com
Jiffy-tite Quick Release Fittings  Motorsports.Jiffy-tite.com
PowerMaster alternator   PowerMasterMotorsports.com
Fuel Tech Fuel Injection Engine Management   FuelTechEMS.com
MSD Distributor, Grid, Boost Control, Coil, Wires, Etc.  MSDPerformance.com

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19 thoughts on “What’s It Take To Run 6.16 In A Street Truck? Look Inside The ProLine Racing Engine That Propelled Larson On Drag Week 2014

  1. Brian Cooper

    Judging by the date stamp on the photos, you assembled it with plenty of time for Drag Week…

    Any dyno numbers?

    1. TheSilverBuick

      Actually, it is probably an MSD one now that I think about it. Same set up under Chad’s Rusty’s hood.

    1. Tom Slater

      My wild-ass guess would be the exhaust valves running hotter & parts in contact with them needing more thermal stability, where the intake valves stay cooler & can use the lightweight alloy.
      That’s just a guess, though.

    2. Tyler Crawford

      Same deal on all the top fuel/alcohol cars . . . aluminum alloy for the intakes, stainless for the exhausts. Would be interested to know but I would imagine 7075 and 17-4.

  2. will

    Now that drag week is over will you guys tear the engine down and check it over? And this sounds odd but did you guys change the oil when swapping fuels? Or at all during drag week

  3. greg

    Damn what a time to be dogass broke… i scheduled the saturday for the headsup race off so i could be in tulsa,but house payment comes before watchin a worlds record pass in person :~( Now i’m still broke n cant make it to Las Vegas…I think thats where we will see the first street legal door car run a 5 second pass then cruise the VEGAS STRIP!!!! GET’ER DONE LARRY!!! Oh by the way Larry’ I’ll by lunch anywhere you want if you can fill out a spot on the bucket list for a ride for my brother in the Nova or S-10, he is fightin colon cancer,and i think that would really boost his spirits!!!

    1. cyclone03

      Greg post your request on the front page for your brother.

      If he’s in Texas I give him a ride in my FE powered Mustang, aint no drag week rocket but it’s noisy.

  4. Mike Gates

    Also stay tuned for Chad’s recap of the week coming tomorrow hear on BangShift.com.
    spelling usage correction…….. Here on BangShift.com
    Excellent article …as a gear head would like to see more of these kinds of articles…some of us just get off on the technical sides of things….Nice pics with the article also …..keep it up

  5. Greg

    The Exhaust Rockers are Steel Because of the Cld PSi they have to open against. And Wanting to Keep the valve train parts as light as they can. and making it live the week.

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