Aircraft Engine Historical Society Members Only

Machining Cylinder Fins
Special-Purpose Maxicut Lathe for Aero-Engine Work

This article first appeared in the Volume 6, Number 66 (April, 1944) issue of Aircraft Production magazine, and is presented here through the kind permission of Flight International. Thanks also to Bruce Vander Mark for furnishing volumes of Aircraft Production for scanning.


One of the problems connected with the manufacture of air-cooled aircraft engines is the economic machining of the cylinder cooling fins (Fig. 1); usually, the sides are tapered and the depth varies to provide equal expansion throughout the length of the cylinder. In the case of the Hercules engine, one bank of fins is eccentric with the cylinder bore. The methods employed by different firms in both Great Britain and abroad, described from time to time in this journal, consist of either turning the fins with packs of narrow tools (Fig. 2) or plunge-grinding with banks of wheels. Some idea of the difficulties encountered may be seen from the Hercules cylinder, which has an eccentric bank of 19 fins with a concentric bank of 20 on each side, giving a total of 59 fins approximately 1.25" deep, the fins are tapered on both sides.


The remainder of this article is available only to AEHS Members. Please Login.