ORIGINAL: dick Hanson
ORIGINAL: Tired Old Man
But NO engine is sold packaged with a tuned exhaust. All are sold with a cheap exhaust diverter or nothing for the exhaust at all. So which tuned system does one rate an engine with? As you noted, a decent exhaust system is a power multiplier, so those willing to spend many, many hundreds of dollars (likely more than the engine cost) could easily stack the power deck by finding and experimenting with the exhaust.
So what exhaust should be used for an accurate power comparison? Logically it would be none for a baseline comparison. Those wanting the most power are dependant on those that have already spent the time and money or need to be willing to toss the dice with their own time and money. Realistically they will need to buy a few different engines and do a lot of exhaust work to find ''the one''.
It's how you look at it
Iwould not consider a noisy setup
and making quiet power requires expansion
so grab a pipe
as for open port comparisons Not really very good as some open port setups spill the mix badly and others do not. ANY of em run better with a pipe or some type expansion setup
the rub is that setting up a decent exhaust system is apparanly a daunting task for some . So the hunt goes on for a setup which is the best with no good system - when the results can never be the best . a conundrum
Dick, you make my head hurt in a good sort of way ... make me think a bit which is painful some days!
In my 40 years plus flying our toys, I bet for every tuned system that I have seen that worked well or worked at all, I have seen dozens that were just expensive, worthless exhaust pipes. For the most part, people just plain don't understand tuned exhausts and choose not to learn about them. Some people such as the pattern and FAI pylon crowd are forced into understanding them ... most of us are simply ignorant and choose to stay that way. Yes, I would put myself in that catagory too. Simple exhaust systems work for most of us unless forced to use something otherwise.
Dick, you are a critic of people such as myself that continue to use simple exhaust systems but you do little to educate us away from our simple ways. I for one would be willing to learn more if directed in that direction. Maybe you could start a thread about tuned exhaust systems. Basic theory, etc. along with examples of products that we could use. Just a suggestion.
As for this thread, the original poster should have stated something about the exhaust system that would be used. When I read something like this thread, I assume simple, conventional mufflers / exhaust diverters will be used on the comparison engines.