Brodak .049 Mk2. Brodak photos.
The original Brodak .049 was intended as a sport flyer's engine This version was designed to give somewhat more power and is a drop-in replacement for the original. It is a beam mount engine and intended for control-line use. The MKII is an AAC design using an aluminum piston, an aluminum liner and chrome plate on the liner, which has Schnurle porting. It is slightly oversquare with a bore:stroke ratio of 1:1.0127 (10.2mm:10.0mm, 0.813cc). It has a die cast crankcase and an alloy steel crankshaft. The overall weight is 48.2 grams.
The engine is designed to run on 10% to 20% nitro with at least 22% oil, ideally a 50:50 castor:synthetic oil blend, and to swing propellers in the size range 5x3 to 6x4, which give an operating rpm range of 12,000 rpm to 18,000 rpm.
These engines are available direct from Brodak.