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Millenium Cylinders

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Capt Harry

May 29, 2005
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I have an A-65, converted to an A-75 during the last major. After not quite 200 hours, two cracks were revealed in two of the cylinders. Rather than use two more, actually four more, overhauled sixty year old cylinders, I opted to purchase four new Millenium cylinders.

The STC from them says that they are for an A-65 ONLY. I understand that the only difference between the A-65 and A-75 is a (1) connecting rod modification that consists of drilling a hole in the end cap to allow better oiling at higher rpms, (2) a larger carburetor venture, and (3) installation of a wooden 70x44 propeller to make it turn more rpm, instead of the wooden 72x42.

It looks to me that if I use the Millenium cylinders, I will have to convert back to an A-65. Obviously, the drilling of the rod end caps would not be a big thing. Does anyone have any experience with such things as the new cylinders on the A-75, and (1) can I leave the old larger venturi in the carburetor, as long as I respect the A-65 rpm limitations, and (2) can I get by with not changing the propeller, as long as it makes the static rpm requirements for an A-65 and I observe the rpm limits for an A-65?

Thanks, Harry Ballance

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