>Ever notice how a thread will steadily creep. The thread
>started out asking about a 50 side exhaust. We are now up to a
>PA 75
>
>Soon we will be at the new Stalker 80, and more than likely we
>will finish up with the Saito 91!!!
It is not so much size, but something else that some people missed here.
The question was: "If you could have any SE engine in the .50 something disp..." Now "50 something" does leave room for a little wiggle here and there, and when looking at the PA series of engines, the 50, 61, and 65 all fit in the same mounting holes and have very little weight differential. And actually, there isn't that much difference in cost, either.
But the real part of the question that I saw was "if you could have any SE engine". Some people have responded by saying they can't afford the more expensive engine or something to that effect. But "IF YOU COULD HAVE ANY ENGINE..." That was the question. If someone was going to give you the engine--if cost is not a factor--then what? What would be your engine of choice? My answer, too, would be one of the PA series of engines. (Now, ask me what car I would choose "If I could have any car...")
Now if you were funding the purchase yourself from the proceeds of your paper route (that's how I started out), or if you are still pounding the engine(s) into the pavement, or if you were only buring a gallon or two of fuel a year, then a less expensive engine might be your engine of choice. But if you are flying a lot, even when you are buying it yourself, this still would be my answer.
In terms of the over all picture, what does your airplane cost you? What about your transportation? What does 60 or so gallons of fuel cost? (That is what it is going to take to wear one of these out). And when you have worn one out, you can overhaul it for less than the cost of a reworked ST 51 and do it all over again. They are a little like the energizer bunny. They keep going and going and... (OK, commercial over. You can send the check to my home, Randy.)
(Disclaimer: I have no commercial interests in any of the above statements or endorsements.)