Weingartner continued, "The manifold is the Edelbrock 2896 Super Victor. It has more epoxy in it than both heads combined. When I added the epoxy to the floor of the heads, it raised the runners, so I had to do the same to the intake to match it. I also raised the floor of the plenum to shrink the plenum volume, and once it was shrunk down, it worked pretty well. I flow tested all the runners, and with the intake attached as well as the carb, they all flowed at least 400 cfm. I was pretty happy with that. The runners were all very consistent."

Cam and Valvetrain

Creating a functional engine combination requires that the camshaft and valvetrain work in harmony with the rest of the engine configuration, and here Weingartner shares his experience: "The camshaft is actually by Chris Straub at Straub Technologies. I had my own specs in mind and tried another cam, and mine just wasn't as good. The cam from Chris was ground by Bullet to his specs, and it made about the same power as mine, but it made more torque. His lobes were not quite as aggressive as mine, and I thought that would lose power, but it didn't. The cam specs ended up at .801/.834 with 260/270 duration at .050, and a 107-degree lobe separation installed at 103.5. Chris also supplied the Morel hydraulic .904-inch lifters for a big-block Chevy. These lifters are really nice and very strong. It is not limited travel, but it will take a lot of spring pressure. I ran them with 275/800 pounds of spring load, and they held up great."

In conjunction with the cam, the valvetrain has to consist of components compatible with the task on hand. Here Weingartner zeroed in on a functional setup through testing on the dyno. "I tried different springs, starting with a 1.625-inch spring and switched over to a 1.55-inch spring with the same pressure. The smaller spring made the valvetrain more stable at higher rpm. I also swapped from aluminum rockers to the COMP Ultra Pro Magnum steel rockers. From measuring with and without the checking springs I found the aluminum rockers had more lift with the checking springs, but with the real springs the steel rockers had more lift. This was because of deflection with the aluminum rockers. The steel rockers didn't deflect as much and delivered more lift. I think that they probably make more power because of that. I used the RHS stud girdle and also went with the ARP 2000 rocker arm studs just to be safe and make sure nothing would break. The valvetrain was very stable after getting the springs figured out, working flawlessly to well past 7,000 rpm.

Finishing Touches

Although an engine of this size would normally benefit from a large 4500-Series Dominator-style carb, for the EMC competition the rules limited the competitors to a single 4150-style carb. Here Weingartner again relied upon dyno testing to optimize the engine under the build constraints. "I used a Braswell 4150, although I also tried another carb that actually made a little more power, I couldn't get it rich enough no matter how much jet I added. The metering inside the carb was just maxed out, and I didn't want to tear up the motor by running it too lean. The Braswell was able to keep up with the fuel requirement at this power level."

Lighting the mixture is an ignition from Australian manufacturer ICE, working in conjunction with an MSD crank trigger. As Weingartner observed, "I ran the ICE ignition with the crank trigger, but I actually tried it both ways—with the crank trigger and without it. You can easily switch back and forth by just unplugging the cable from the trigger and hooking it to the distributor, and it turns out I didn't see a power benefit. It did keep the timing more stable, so that is a plus with the crank trigger. Also, if we had to swap the intake manifold we didn't have to worry about resetting the timing, so that is an advantage."

Makin' Power

We had a chance to see Weingartner's big-block in action against the SuperFlow Powermark dyno at the 2013 AMSOIL Engine Masters Challenge, where in terms of raw power, the engine was among the leaders. Certainly from a dollar-per-horsepower perspective, it was at the top of the heap. Here we had a powerplant that embodied the potential of a conventional big-block Chevy with everyday parts—essentially, it was a traditional hot rodded big-block. From its factory deck height block, to the OEM layout replacement heads, as well as the single four-barrel 4150 induction, this engine resembles everyman's hot street big-block.

Where this engine really separated itself from the pack was the sheer twist and pull against the dyno's brake. Right at the hit we witnessed 634 lb-ft of uncontrollable torque, rising steadily to a peak of 759 lb-ft at 5,400 rpm. That torturous torque will twist a stock Camaro in half. Powering up to a peak of 852 hp at 6,600-6,700 rpm, the top end punch is right in the sweet spot for a knockout blow on the street. Chevrolet engineered the potential for this kind of power decades ago, and performance engine builders like Weingartner Racing have been making the most of it ever since.

On The Dyno 540ci Big-Block Chevy

3,000 634 362
3,100 630 372
3,200 611 372
3,300 578 363
3,400 565 365
3,500 579 386
3,600 601 412
3,700 625 441
3,800 649 469
3,900 669 496
4,000 687 523
4,100 697 544
4,200 711 569
4,300 721 590
4,400 727 609
4,500 732 628
4,600 739 647
4,700 746 667
4,800 751 686
4,900 753 702
5,000 754 718
5,100 755 733
5,200 757 750
5,300 758 765
5,400 759 781
5,500 758 794
5,600 757 807
5,700 752 816
5,800 747 825
5,900 741 833
6,000 732 836
6,100 725 842
6,200 717 847
6,300 709 850
6,400 697 849
6,500 687 850
6,600 678 852
6,700 668 852
6,800 654 847
6,900 641 842
7,000 627 836

By The Numbers 540ci Chevy Big-Block

Bore: 4.500 inches
Stroke: 4.250 inches
Displacement 540 ci
Compression ratio: 11.5:1
Camshaft: custom Straub Technologies hydraulic roller
Valve lift: .801/.834 inch
Rocker and ratio: COMP Cams 1.8/1.7:1
Piston rings: Total Seal 1.5/1.5/3mm
Piston: MAHLE forged
Block: Dart
Crankshaft: Scat forged
Rods: Scat 6.385 inches
Cylinder head: RHS 320 cc
Intake valve diameter: 2.300 inches
Exhaust valve diameter: 1.88 inches
Intake manifold: Edelbrock
Carb: Braswell 4150
Header: Hedman 2-inch primary
Ignition: ICE/MSD
Damper: Powerbond
Oil Pan: Hamburger
Fuel: VP 100 Unleaded

925 Tower Ave.
WI  54880
Weingartner Racing Engines
VP Racing Fuels
P.O. Box 47878
San Antonio
TX  78265