|
Constant Speed (CS) versus Fixed Pitch (FP) |
| IO-320 (160 HP) CS | IO-360 (180 HP) FP | |
| Weight (lbs) | ||
| Engine | 290 | 297 |
| Prop | 55 | 40 (Sensenich Metal) |
| Total | 345 | 337 |
| Cost ($) 2008 | ||
| Engine | 22950 | 24600 |
| Prop and governor | 7475 | 2135 |
| 6 Year Overhaul | 2000 | 0 |
| Total | 32425 | 26735 (-5690!) |
| RPM on take off (Static) | 2700 | 2200 |
| Power on Take Off (HP) | 160 | 180 - 20 (4 HP per 100 rpm*) |
| = | 160 | 160 |
* Source Vans RVAtor article
My Conclusions.
Plus - the IO-360 FP combo is 8 lbs lighter, has same HP on take off and is $5690 cheaper. It has one less thing to go wrong/service. With a composite FP prop the weight will be even less, which will allow for a small 2nd alternator and thereby not affecting the c of g too much, and will run smoother
Minus - less efficient. Have to monitor RPM more closely during aeros/descent (did that in CAP10B). Less drag on landing.