Table of Contents
Engine Setup and Early Hurdles
The project began with a basic engine that had been tuned for normal operation. The team had already performed a standard tune‑up, ensuring proper idle mixture, clutch settings, and a smooth idle. However, the engine was only intended for short warm‑ups, burnouts, and a few 60‑footer runs. The goal was to get the car moving on the track, not to deliver sustained high performance.
From the outset, the engine’s configuration was temporary. The current setup was chosen for simplicity, with the understanding that it would be replaced or upgraded once the car was ready for more demanding runs. The team had a fresh block that was machined and ready, and they were in the process of procuring additional parts to support the nitro conversion.
Critical Failure Points and Component Modifications
One of the first observations was the condition of the cylinder heads. The heads had been sent to a machine shop where the O‑rings were replaced with stainless steel versions. The original copper gaskets were still intact, so they were annealed and reinstalled. Despite these precautions, the heads displayed significant tarnish due to the corrosive nature of nitro fumes, which attack steel and iron aggressively.
Another major concern involved the exhaust rockers. The original cast rockers were designed for a 190‑horsepower production engine and were not built to withstand the high pressures generated by a nitro motor. Under load, the rockers would split or crack, especially where the stud, shaft, and bridge intersect. The team decided to replace these with hard‑chrome‑finished shafts to improve durability.
The head bolts presented a similar issue. The original Chrysler bolts were rated for 75 ft‑lb, insufficient for the stresses of a nitro engine. The team over‑torqued them to 100 ft‑lb, which is the standard for the setup, but they acknowledged that under sustained high load the bolts could snap. They planned to replace the bolts with stronger studs for future builds.
Exhaust and Intake Considerations
The exhaust headers were a point of contention. They were originally designed for a rear‑engine car and angled straight up, which is unsuitable for a front‑engine dragster. The angled design would block the driver’s peripheral vision and allow smoke to obscure the track, making the car effectively blind during a run. The team recognized that the headers would need to be replaced with slingshot‑style headers that angle back, keeping the exhaust clear of the driver’s line of sight.
Intake rockers, on the other hand, were in better shape. The intake side of a nitro engine experiences less pressure, so the existing rockers were acceptable for short runs. However, the team noted that the push rods were undersized for the early Chrysler design, which could lead to deflection under high load. They considered using thicker push rods to match the geometry of the original 426 Hemi design, which would provide better support.
Clutch, Throttle, and Safety Modifications
The clutch and throttle system required significant adjustments. The original throttle pedal was mounted in a way that made it impossible to remove without taking the entire engine apart. The team cut the pedal and welded it back on later, allowing easier access for maintenance. They also relocated the throttle pedal to accommodate the new clutch setup.
Safety features were addressed by adding blowback devices to the engine can. These devices attach tabs to the can to prevent it from separating from the motor plate in the event of an explosion. The team also installed a new oil pan with a deceleration baffle to keep oil in the pickup during braking, preventing loss of lubrication.
The steering and reverser systems were integrated into the build. The cross‑shaft, steering box, and reverser were all installed, and the driver’s seat was positioned to maintain a clear view of the track. The team emphasized the importance of ensuring that the driver could operate the car cleanly without interference from the mechanical components.
Future Steps and Ongoing Work
With the basic mechanical components in place, the next phase involves plumbing the fuel system and installing the blower. The team plans to finish the intake manifold and blower assembly by the end of the week, followed by a thorough test of the fuel system. They also intend to finalize the oil pan and ensure all safety devices are properly secured.
Throughout the process, the team has highlighted the complexity of converting a standard car into a nitro‑powered machine. Each component—from the headers to the head bolts—requires careful consideration to avoid failure under the extreme conditions of a drag race. The project serves as a reminder that success in this arena demands meticulous attention to detail and a willingness to replace or upgrade parts that were never designed for nitro use.
As the build progresses, the team will continue to document each step, ensuring that future builders can learn from the challenges encountered and the solutions implemented.