ORIGINAL: LouW
To give you an idea as to how the PAW19 compares to a glow 2-stroke and a 4-stroke, this is some test data for one of each that I flew in the same airplane. The figures are all with the same propeller:
The first was a K&B Sportsman 20.
Installed weight = 9.6 ounces
Full throttle = 11,790 rpm
Idle = 2,850 rpm
The second was the PAW 19.
Installed weight = 6.8 ounces
Full throttle = 9,600 rpm
Idle = 2,800 rpm
The last was an ASP 30 four stroke.
Installed weight 8.5 ounces
Full throttle = 10,800
Idle = 2,650 rpm
10-5 master prop
Performance of the airplane was similar with each engine. The engines were tuned for flight which in each case is just a little rich of peak rpm. It was a little more spritely with the Sportsman 20 as you might guess from the figures.
The K&B Sportsman >20 is 85% more powerful than the Chinese >.30 4-stroke and is (I am sure) of a similar degree of quietness, and has a 20% better Max/Idle rpm ratio. These factors ought to put to rest the frequently stated poor opinions about K&B sportsman engines.
Add the 50 or so bucks for a Davis Diesel cylinder head and you might reasonably never consider a (simple and inexpensive?) 4-stroke over a "dirty" Diesel again!
Morty.