ORIGINAL: dick Hanson
A properly designed muffler which is not tuned is also a very good choice -- the model of JMB I like is that type can - run on a very short header - the powerband is seamless from idle to full power.
Once you tune to a boost - there is a point --somewhre in the band which is the transfer from below resonant to resonant.
Hello Dick,
Many years ago, I was experimenting with large props on a piped Top Flite Contender. I cut many lengths of aluminum tubing, and used an additional silicome coupler to add this additional tubing between the header and the pipe. I found a big increase in power at lower RPMs (for a given large prop size), as I lengthened the header with these extensions.
Do you know of anyone who sells a thrust tester these days? I used to have one, but no longer (don't remember who I loaned it to). I guess I could build one with a fish scale and an engine test mount on a sliding track...
Anyway, do you know of anyone who has worked out and published the approximate header lengths for .40-.60 sized engines tuned for lower RPM operation?