I've got some experience with the GO-300 on a Cessna 175, as well as having had discussions with people familiar with 175s as owners.
The consensus is that the problem is not with that engine, but with operating technique. If the GO-300 is operated at the rpms of an ungeared engine, such as 2700 rpm, it tends to overheat, thus needing cylinder replacement. Operated at >2900 rpm, the engine is quite comfortable, and overheating does not occur, and it is, IMO, reliable. Pilots who are used to ungeared engines cringe at those figures, because that is far above familiar redlines, so they try to operate it at ungeared engine speeds, such well below 2700 rpm. That's a costly mistake, and it gave the 175 what I consider an undeservedly poor reputation. That has made the 175 cheaper than they deserve to be. Operated correctly, the consensus is that the engine usually makes TBO. Of course, there are a lot of other factors that influence reaching TBO, but low rpm operation definitely reduces it on that engine. BTW, because it was swinging an 84" prop that was possible because the gearbox was atop the engine and gave greater ground clearance, it sure helped performance on the Cessna 175. It matched the performance of a 175 that had been converted to a Lycoming 0-360 with, as I remember it, a constant speed prop. Having a 6 instead of a 4 also meant smoother operation. A bigger prop doesn't necessarily mean more efficient operation, nor does a constant speed prop, because there are a lot of variables (added weight is one of them). The 175 had the prop sized and geared right for the engine and airframe by Cessna engineers. On 5/7/2013 9:00 AM, krnet-request at list.krnet.org wrote: > Something to remember is that Continental also made a GO-300 that uses the > same rods and bearings, and a slightly different piston. Same compression, > not really any beefier, but turns 3100 or 3200 RPMs. They are also a 1200 > hour TBO, just for comparisons sake, and often times don't make that.
