View GarageI hadn't heard of these before, so I thought I would post it up in here for anyone else who may be interested.
I think this motor was in the Holden museum that closed down, so I don't know where it is currently. In 1966, Phil Irving and Bob Chamberlain decided to design a better head for the 186. The one pictured is one of the first 6, and was cast in steel. Another 25 were cast from aluminium before they gave up on the project.
They were a "Heron" type cylinder head, meaning that the combustion chamber was in the piston, and the head was only relieved for the valves. On the dyno, they used three SU's on one set, twin Stromberg's on another, and a 4 barrel Holley on a third. All three made up around 150HP, when the standard engine only made 90.
The one problem they couldn't fix was overheating, which is why it was wound up in the end.
Cyclone head 1.jpg 182.53K
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