Indy Cylinder Head's recipe for reliable street performance delivers a broad powerband and 700 lb-ft of torque.
Grunt, Oomph, Twist. That's real power.
Power is what Mopars are known for. At the root of that power, the key to wheel-lifting launches and asphalt-rippling burnouts is torque.
Ken and the crew at Indy Cylinder Head started with Mopar Performance Parts' cast iron str
Torque is also what defined '60s muscle cars. While today's four-valve, DOHC, fuel-injected vehicles offer performance, you don't hear much about torque-nor do you feel it. Today's high-revving, light-switch-for-power engines are super-efficient, clean burning, and high-revving. But they lack pin-you-in-your-seat power that forces you hang on when the pedal hits the floor. Heck, in some cases, a torque monster doesn't require even moderate accelerator pedal travel.
Perhaps that is why when Holley chose to build ten project cars-one from each decade of the company's existence-there was no question that the automotive selection for the decade beginning in 1960 would be a big-block Mopar. Holley Performance Products and its brands including Lunati, Hooker, Earls, Holley Superchargers, Weiand, and Nitrous Oxide Systems all have an affinity with large cubic inch, V8 muscle. The choice to go with a Mopar for a decade as important as the '60s is significant commentary regarding whose muscle cars made the most power consistently.
Torque is the back-to-basics commentary-but how would one add a twist of today's trends. When Holley approached us about their Project Roadrunner, they asked who we thought should engineer the Mopar-specific powertrain combination. Certainly, the answers could range from a crate Wedge or Hemi from Mopar Performance Parts, but that might reduce the potential content of Holley brands in the engine assembly. With the goal of exhibiting Holley's brands, we suggested that Indy Cylinder Head be the engine builder. With their loyalty to the Mopar community-displayed in their long list of products made specifically for Mopars-as well as their far-reaching reputation, we knew that Indy would be the place to go.
Indy's capability as a full-service engine builder extends from their own block and cylind
Holley agreed-in fact they had already come to the same conclusion prior to our suggestion. Holley would look to Indy Cylinder Head for the gospel according to Mopar big-block power. In the early discussions with Ken Lazzeri of Indy Cylinder Head, it was apparent that there were several options-maybe a mid 400ci low-block stroker or perhaps a huge displacement 440-based RB. The intended use is what helped to make the final decision of which displacement big-block Mopar to build.
The Holley Performance Products Project Roadrunner would be a street car. Sure, it might do a quarter-mile once in a while, but primary use would be cruising-even long distance Hot Rod-style Power Touring. This Roadrunner would be four-speed shifted backed up by the stoutest Hemi A833 possible, yet produce enough torque that you could basically leave it in Third all the time.
Lazzeri told us, "We have built many 500ci pump gas engines and they were capable of 600 to 610 lb-ft of torque and nearly equal horsepower-in street compression. Additional displacement was the key to building a torque monster." Ken also knew that a bit more displacement may pull down the horsepower figure, but the torque would rise exponentially. "When you try to create a torque monster on purpose, the equation is fairly simple-moderately high velocity heads and a relatively small camshaft. You sacrifice peak horsepower."
Sacrifice horsepower? "Heresy," you say. Ken continues, "The reality is that building high-torque engines puts horsepower on hold. Our goal was torque first." Remember, horsepower is a function of torque. The polar moment of inertia happens sooner when the fulcrum favors the power source rather than the object to be moved.
Specific machine work for the 542ci combination includes clearancing the lower skirt of th
Because Ken chose to accommodate the use of a Lunati crank in this application, additional
The popular P4529851 block features both the Hemi mounting pads and the Wedge motor mount
The popular P4529851 block features both the Hemi mounting pads and the Wedge motor mount
You get more torque with a bigger stroke and the benefit of that higher displacement is that torque is anticipated. When you couple it with a mild camshaft, moderate compression, and street hardware, you get the maximum reliability, very smooth running operation, and in our case, over 575hp. For those of you who are counting, that's still more than one horsepower per cubic inch. That, with a mere 9.5:1 compression-it'll run on any gasoline in the world. Best of all, while premium components are used, the engine internals are far from exotic.
To gain the torque figures that would test transmission and the abilities of driveline components, Ken proved that it can be done with off-the-shelf parts. To gain high-horsepower at the sacrifice of torque, even larger heads, race compression, and radical roller cams would get this same displacement right up to the 800hp. But torque rules the street.
The goal was torque and Ken Lazzeri certainly made good on his promise. Ken says, "Indy Cylinder Head has built many of these engines at 500ci, and we wanted to know what would happen if we did a 542. The result was that the torque went way up. With the 500ci combination, 600-610 lb-ft is about the max. The additional 42 cubic inches proves that there's no replacement for displacement as Ken went up to 700 lb-ft with this combination.
All results gained from Indy Cylinder Head 300 rpm/second Acceleration Test conducted on SuperFlow 901 dynomometer.
Part of the effort in building the 542ci stroker RB engine for Holley Performance Products
Ken Lazzeri is quick to point out that the Lunati crank is made of excellent material, how
Obstacles to making this work are apparent first from the view of the flywheel flange. For
The Lunati forged, 40cc reverse-dish piston offers the 542ci Indy engine ample combustion chamber size, despite a zero piston deck height and the 78cc chamber volumes of the Indy 440SR heads. This is important. In order to eliminate any chance of detonation with the moderate 9.5:1 compression ratio, the temperature throughout the chamber must be consistent. As a result, combustion occurs predictably across the piston surface. As bore diameters increase, this "squish effect" is harder to control, and when not considered, detonation is a likely result.
The series of narrow grooves just below the piston surface are anti-detonation grooves. They also help reduce the chance of detonation as the grooves disperse raw fuel along the cylinder wall through piston travel rather than allowing it to reservoir along the ring and piston top surface.
While on the topic of rings, the set is made up of 1/16, 1/16, and a 3/16 standard tension oil ring. The Holley Roadrunner will primarily be a street machine, yet we intend to do a little racing. We made it clear to Ken that we wanted both power and seal without the oil contamination that looser, high-horsepower race engines are known for.
The cylinder head for the 542ci Holley Roadrunner would be Indy's 440SR head. Using 906 castings as a baseline, the 440SR is Indy's first step in terms of a performance gain with its extensive line of Mopar-specific B/RB cylinder heads. Designated a street/strip head, the 440SR is the closest thing to a stock replacement that Indy offers. It doesn't require an offset rocker arm-any 906 style rocker will work, as will any intake manifold in the aftermarket.
According to Ken, "Our goal with this head in this application was to produce a peak intake airflow rate of 320cfm while maintaining intake port runner volume at a moderate 270ccs compared to a ported 906 head's volume of 190cc."
As for flow balance, the exhaust port is 75 percent of the intake and deemed a high-velocity head, perfect for the moderate airflow goal we were interested in obtaining. "Will the 542 make the most horsepower with this head?" you ask. "No," according to Lazzeri. "This engine has far more potential-it is basically a detuned race engine specifically designed for a street machine. With a much larger port volume and greater airflow volume rates, the 542 could easily produce 800hp with a roller cam, high compression, and fully ported heads-maybe even with the 440SR head."
Ken is quick to note that Mopars have always been well known for torque. "Recognize that the 320cfm intake airflow rate for a 440 may have seemed large for a torque-only engine, but remember Chevrolet offered airflow rates of 270cfm right from the factory with 396 Chevrolets." As airflow goes up proportionately with port size, so does horsepower, as long as the engine can effectively pump the air available.
Sure, a race-compression 542ci engine could produce 800+ horsepower, but what we wanted was street reliability and torque. Opening the Lunati catalog to camshafts, Ken chose Lunati's hydraulic PN 33706. Technically, it has the look of an MP Purple Shaft cam with a generous 110-degree centerline. Specs are .507/.534-inch lift, intake and exhaust, respectively, with an advertised duration of 285-degrees on the intake and 295-degrees on the exhaust. Duration at .0500-inch lift is 235/245, intake and exhaust, respectively. Ken chose to install the cam 3-degrees advanced, reducing the centerline to 107-degrees. For those of you with 383s, 400s, and 440s who think this cam is a bit too aggressive, remember, our displacement is 542ci. Ken says, "With that kind of displacement, you don't even hear the cam at idle."
A Lunati 3-position cam chain and sprocket set is used as a Roller thrust button to reduce friction. Here, Ken readies the thrust button for installation with a liberal coating of lithium grease for startup and break-in. No oil is squirted to this location.
|Description ||Source ||Part No. ||Other Info|
|Cylinder Block||Mopar Performance||P4529851||Water Wedge Block|
|Crankshaft||Lunati||4.5-inch inch x|
|Piston Rings||Speed Pro||R9799-5|
|Main Bearings||Federal Mogul||119M std.|
|Rod Bearings||Federal Mogul||8-7300SHA|
|Cylinder Heads||Indy Cylinder Head||440-S/R||Super mod porting,|
| diameter stainless|
| steel valves|
|Cam Button||Lunati||90004||Roller bearing|
|Timing Chain Set||Lunati||9 33125||True roller|
|Head Bolts||Indy Cylinder Head||440-16|
|Rocker Studs||Indy Cylinder Head||440-11|
|Rocker Shafts ||Indy Cylinder Head||440-14|
|Oil Line Kit ||Indy Cylinder Head||440-10|
|Pushrods ||Indy Cylinder Head||440-9||9.50-inch length|
|Valve Covers ||Indy Cylinder Head||440-7||Indy logo’d|
|Intake Manifold ||Indy Cylinder Head||440-20||Dual plane|
|Gasket Set ||Indy Cylinder Head||440-33|
|Oiling System ||Indy Cylinder Head||Indy MAXX street|
|Spark Plugs||Champion||404||Gapped @ .025 inches|
|Distributor||Mopar Performance||P4120942||Locked out advance|
|Carburetor||Holley||80497||950cfm Pro Series|
| w/ vacuum|
|Ignition||Holley||800-300||Holley Pro Annihilator|
The overall simplicity of the top side of each cylinder head adds to the durability and re
For the ultimate in street performance, what else would you choose besides a dual-plane in
To ride aboard the giant dual plane, a carburetor capable of 900+ cfm of airflow was neces
If you were to label anything about this combination as exotic, you may look to the oiling
Indy's SR heads require the use of Indy's 440-10 external oil line kit for rocker arms. To
The Indy MAXX external pump with spin-on filter was necessary as noted previously by the e
The pan-mounted oil line is situated to allow use of stock motor mounts. The external feed
As part of the camshaft degreeing effort, Ken measures plunger travel at the cam lobe at .
Another critical measurement is the deck height spec. The zero deck height of the 542 engi
Once the cam was degreed to TDC, final assembly included the use of a conversion keyway in
Indy's dual-plane intake has a raised intake and does not have an integral airgap plate, n
In order to gain seal between the valley cover and the bottom edge of the 440SR heads, a b
Prior to buttoning up the final assembly and dynoing the combination, Ken adjusts the rock