NIB Valach 170cc four stroke, a very powerful engine mostly used in big scale project but can be used in any large 40% aerobat to 60 lb scale plane. it swings a 34X12 and when broken in, the recommended prop is a 34X14, the prop used on the larger 200cc engines, perfect for the big 3.1 Yak 54. it comes with ignition, plugs, plug wrench, short spacers, Prop washer and bolts, and instruction manual, no other prop drill jig will work so I bought and added at no cost the Valach drill jig, I saw and heard one at an event in Md on a 50% Christian Eagle, it sound amazingly like a real aero engine. as with the smaller fuel four strokes, they are more expensive than the two strokes. the measurements are, from each cylinder head is 14in. wide, from the prop hub to the rear mount is 8 1/2in, add another 1 1/4in for the spacers. and like the better big two strokes like 3W and DA, they do not come with mufflers which on four strokes are not required but recommended, at an additional cost I have the complete exhaust system, I have the scale two in one header and canister system, the two header straight pipe system, I also have the the Y joint that the two headers can connect to forming the two in one straight pipe system, the engine came from Aircraft Modelers Research in Canada and sell for $2648 USD, that is the converted CAD price of $3349. Volgelsang Aeroscale is the only US dealer selling this engine and do so at a similar price. I'm selling mine for $2000. the complete all three exhaust system for $250. I also have several new, never drilled 34X12 and 34X14 Xoar Laminate props, these are props made to order, not sold in stores, they went for $95. ea, mine $70. ea. everything brand new, never used in any way. This engine has been reduce lower than you will find a four stroke this size anywhere.