Off-the-shelf JE forged pistons...
Off-the-shelf JE forged pistons had to be cut for the nonstandard valve location in the B-1 cylinder heads. The pistons were then coated with both a thermal-barrier coating on the piston tops and a friction-reducing coating on the skirts.
All the machine work on the...
All the machine work on the block was performed by Speed-O-Motive using state-of-the-art Rottler equipment. The Rottler three-axis machine can hold amazingly tight tolerances, down to the ten-thousandth of an inch.
Brodix B-1 cylinder heads...
Brodix B-1 cylinder heads offer huge ports, giant valves, and high-flow capability. With more time to experiment with cam selection, Speed-O-Motive could have certainly optimized this combination. Even so, their 717 hp and nearly 600 lb-ft of torque were good enough for a sixth place finish.
Custom oil-return lines were...
Custom oil-return lines were fabricated to route top-end oil away from the rotating assembly and back to the crankcase quickly.
The Top End
Cylinder head selection is vitally important in a performance engine, so Speed-O-Motive chose Brodix original B-1 heads for their build. These heads offer huge 2.30-inch intake valves and giant port volume, which can equate to very high flow numbers. Mark Hyla, Speed-O-Motive's cylinder head porter, ground away even more material from the heads to correct for core shift and to optimize port flow. In fact, a pound and a half of aluminum was removed from each head during porting. Comp's No. 948 valvesprings were utilized to keep everything stable at rpm. Rocker arms were 1.7 ratio roller units from Koffel's Place and were modified for a cup-style adjuster so double-ball-ended pushrods could be used. Valvetrain geometry problems dictated the rockers be shimmed 0.200 inch for reliable high-rpm use. A single-plane, 4500 flange intake manifold was placed atop the B-1 heads and topped with a 1050 three-circuit Holley Dominator. Three additional horsepower were gained by running a 6-inch-tall K&N air filter on this engine. While B-1 original heads are generally more suited to higher-compression, higher-rpm engines, we feel Speed-O-Motive did a great job adapting this head to run on pump gas at less than optimal rpm.
The huge ports of the B-1...
The huge ports of the B-1 original heads allow the engine builder to simply look down the intake runner to check port alignment. Speed-O-Motive ground over a pound of aluminum from each head to correct core shift and optimize flow.
Efficient combustion chamber...
Efficient combustion chamber design is just one of the benefits of B-1 heads. While not necessarily the perfect choice for a low-compression street engine, Speed-O-Motive adapted them well to the application.
To correct valvetrain geometry,...
To correct valvetrain geometry, 0.200-inch shims were placed under the rocker-shaft stands.
On the first attempted nitrous...
On the first attempted nitrous pull, the engine pulled strongly, but then flattened out and wouldn't accelerate. It was determined the coil on the dyno wasn't strong enough to jump the spark-plug gap in a nitrous application.
On The Juice
Nitrous oxide brings two thoughts to the mind of the automotive enthusiast. First, nitrous is a great way to make inexpensive power. Second, nitrous is a great way to blow up an engine. In our opinion, there's truth to both as we've seen properly tuned nitrous engines make tons of reliable power. When applied to an improperly tuned engine, however, nitrous oxide can be disastrous. So when Speed-O-Motive and ZEX teamed up to test a 300hp nitrous kit during our engine challenge, we thought it was a no-lose situation. Either we'd see big power or a big explosion, and either makes for a good story. Fortunately, thanks to a solid engine built by Speed-O-Motive, a great nitrous kit manufactured by ZEX, and a little tuning help from the guys at CFM and ProMax, the engine performed flawlessly and set Comp's "unofficial" dyno record in the process.
We ended up a little ahead...
We ended up a little ahead of schedule, so the crew from Speed-O-Motive made an arrangement with ZEX to test their 300hp, perimeter-plate, nitrous-oxide system. Confident in his engine, August Cedarstrand agreed to pull the trigger, claiming we couldn't blow it up. We tried, but he was right-the engine stayed intact.
With the official contest...
With the official contest dyno pulls complete, it was time to have some fun. Since Comp's dyno team got us ahead of schedule, we decided to really test the endurance of the big-block Chrysler by hitting Speed-O-Motive's engine with a 300 shot of nitrous!
Ben Gorman and the team from...
Ben Gorman and the team from ProMax/CFM pitched in to help install the kit and tune the engine for nitrous. These guys have built and raced nitrous engines for many years, and their experience really helped.
So what did we learn by spraying the juice to Speed-O-Motive's big-block? First, we learned properly-tuned nitrous oxide is a very cost-effective way to add power to the big-block Mopar. Second, and contrary to popular belief, we learned a factory block can withstand the strain of nitrous oxide without damage (at least for a little bit). Third? Well, third, we learned that using nitrous is just plain fun. We'd like to thank Comp, ZEX, Speed-O-Motive, and everyone in attendance for playing along.
Bottle pressure was a little...
Bottle pressure was a little under the preferred 900 pounds-per-square-inch, so warm water was used to heat the nitrous bottle. Ignition timing was also backed off 2 degrees per 100 hp of nitrous, or a total of 6 degrees.
When a good pull was achieved,...
When a good pull was achieved, the results were impressive. Even with a nearly empty nitrous bottle and less-than-optimal coil, the engine made nearly 985 hp and more than 800 lb-ft of torque! With a full bottle and additional tuning, 1,000 horsepower would certainly have been achievable. Even so, dyno operator Rich Smith told us these were the biggest numbers he'd seen since working at Comp.
Even after the challenge pulls,...
Even after the challenge pulls, plus two aborted and two complete nitrous pulls, there was no indication of damage to the engine. Proof that nitrous oxide-if used properly-is a safe and economical power adder.