All photos by Paul Chapman.
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All photos by Paul Chapman. |
This was the next F1J engine to appear on the market after the Shuriken. It was an Italian engine made by Alberto dal Oglio. While the Shuriken in its four variants was the only engine made by Fred Baldwin and Jim van Arsdall, Alberto was already well known for his excellent 2.5 cc engines and this experience shows in AD-06's greater power output. The engine is no longer available, but was the standard to judge other engines by until the Cyclon 06 appeared.
I have never owned an AD-06, but samples typically ran at 29000 rpm on APC 6x2 and 25% nitromethane. It was a twin ball race engine using a heat treated steel cylinder liner with a cast iron piston. The glowplug was a proprietary glow button, secured by a ring clamp that enclosed the button body and screwed into the head. The prop driver was collet mounted. The engine was supplied with the semi-streamlined prop nut seen in the photos.
The crank case was a gravity casting. Like all AD engines, the alloy used was specially formulated by Alberto. The casting and all external components apart from the needle assembly had a plain white metal finish. Its noticable that the upper and lower cylinder fins look quite different. Both sets of fins were cast in a block as part of the crank case, but while the upper fins were formed by turning the crank case on a lathe, the lower fins still have a cast finish on their outside edges. They were probably formed with a gang of slitting saw blades on a milling machine.
The backplate centre boss has a blind hole so it can be more easily drilled and tapped to provide a low pressure feed to a hard tank.
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