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426 Hemi With Big Loads of Nitro: Ramcharger Recollections #18

426 draft engineWe really struggled with learning how to run big loads of nitromethane because we were looking for the proper air/fuel ratio. Consultation with the Chrysler Chemistry Lab was not particularly helpful, but one of the chemists did say that the nitrogen could form an explosive and that was a completely different kind of chemistry.

A literature search disclosed some tests conducted on drums of nitro to determine the class of chemical for truck and train shipment. They had dropped drums of nitro from aircraft and did not produce an explosion or fire. When ignited at atmospheric pressure, the flame was lazy, with little heat generated.

So we continued to test on the Tuesday Test Days at Detroit Dragway. The lab car, #558, was the primary test mule, and the Ramchargers tested with our racecar. As stated earlier, there was a small fuel tank mounted on the radiator yoke that allowed gravity feed to the Hilborn fuel pump. Hilborn had supplied a shut-off valve installed between the tank and pump. We found out the hard way that the valve leaked. On at least three occasions, twice in #558 and once in our car, there was a large detonation upon the first revolution during starting. The detonation pushed one piston down over the crankshaft with the rod looking like a pretzel. The side of the block was blown away, both outside and into the tappet chamber. The head and intake manifold were broken, and camshaft was also lost. The headers were salvageable, with welding, but most of the engine parts were lost.

The leaking fuel shut-off valve allowed nitro to leak down into the injectors and into the cylinders with open intake valves. Upon cranking the nitro was subjected to critical pressure and detonated. Needless to say, we located a better valve, and from then on we shut down the engine by cutting off the fuel.

Although there were many clues, we never did figure out that the key to running nitro was to simply put more in. The air is simply a carrier of the fuel into the engine and is not material in the combustion process.

426 Hemi engine dyno test

We purchased a new Woody Gilmore dragster chassis and continued development of the 426 Hemi, blown and on fuel. We broke many, many engine parts, most of them spectacularly. It was clearly the most powerful AA/FD in the country when it made it the full length of the track. In those days, dragsters dumped the clutch and drove out of the tire smoke. Our car would not drive out of the smoke, leaving tire marks to the finish line.

Problems were numerous: bearings, head gaskets, wrist pins, and pistons. Things that worked on the 392 Hemi did not work on the 426. The driver, Don Westerdale, always had blisters around his eyes. The engine would blow, sending the oil back into his face. When he pulled down the goggles the fire came.

There is a photo, which seems to be lost, of the car crossing the finish line at Detroit Dragway with the blower and fuel injector higher than the light poles.

Dan Knapp led the dragster effort, and he stubbornly attacked each problem and the car became progressively more reliable. The car attracted the attention of track promoters, and it was booking match races and exhibition runs. It was during one of these exhibition runs, near Niagara Falls, Canada, that Knapp began to play with spark advance. We had been running 36 degrees as the best power on gasoline. He bumped it some and the car went faster. He bumped it again, and the car went faster again. The engine took on an entirely new sound at idle, the one we are now familiar with in all blown fuel cars. When they got home the lead was measured at 75 degrees. We managed to keep this a secret for nearly two years. Don Garlits claims he made this discovery.

Allpar thanks the North Georgia Mopar Club for permission to re-run earlier parts of this series, and to keep going with the rest.

Talk about the series in the Allpar Forums • Read other Ramcharger Recollections • Allpar racing page

1. Introduction: Joining the Ramchargers10. Drag Racing the Hemi19. The 1965 championships
2. 1961 Super Stock racing, experiments11. 1964 Hemi Domination 20. Puzzling results in ’66
3. Racing a Chevy on its home turf12. First Late-Model Hemi Dragster21. Rocket fuel, girdles, and springs
4. Trying Automatics13. Max Wedge Family Car22. Squirrely runs and a strong finish
5. 1962: Max Wedge, Indy Nats, Big Trucks14. Birth of the Funny Car23. Back in the engine lab...  
6. Al Eckstrand’s Last Ramchargers Race15. The Trip from Hell24. A revolutionary new body
7. Testing Tires and a New Rig 16. Clobbering Ford, “Funny Cars”25. Supercharging the big Hemi
8. Match Racing, Engine Lab, Jail17. Nitro ’6526. At the SAE presentation, 2012
9. The Hemi: Elephant Rising18. Big loads of nitro27. The 1967 racing season


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