I'm considering upgrading my PA28-140B to 160hp. The current prop is pitched 56". I know I will need to re-pitch, but was wondering what pitch you 160hp guys were running.
I think the rule of thumb is to go up 2 from what you were running. If your current prop allows you to go much over red-line in straight and level flight you may want to go up 4.
The Piper Service Manual calls for a 60 inch as standard for a PA28-160 (Page 1b19). You can run more if you have a very slick airframe, but 60 would be conservative.
I have a 160 hp PA28-150C, and I run a 62 inch (which statics about 2295 rpm on my engine). However, my airframe is fairly slick (refer to my post this morning titled "Tips and Tach"
Looks like Art Mattson's STCs, and the pistons, rings, and pins from ECI are the lowest price on market today for doing this upgrade. I have stock Lycoming steel cylinders on my engine. My AP/IA suggests to send the cylinders off to Sal's Aircraft cylinders in Dallas, TX to have them looked over for overall health, and if the valves need reground, etc, and have the new pistons and rings fitted there as well. This will be almost like a top overhaul.
You need to weigh the cost of new pistons and cylinder overhaul against the cost of new cylinders. You may find that it is not that much higher to go with new.
My 140 has the 160 hp upgrade with Art Matson's prop mod and most of the other speed mods available. We pitched the prop to 61" and that has worked very well. Static RPM runs about 2295 to 2305, so that is higher than required by the FAA's Type Certificate Data Sheet 2A13 (2275 RPM). Initial rate of climb has been between about 700 fpm at gross weight on a hot day to about 1100 fpm at lighter weights on a cool day at about 100 mph indicated. This are flights initiated from about 500' msl airports.
A recent speed run on a cooler than normal day at about 2200' density altitude and light weight produced 2675 RPM and IAS of about 150 mph. At 2300 RPM, it was indicating about 130 mph. I didn't figure the TAS.
Next month we'll be installing a Powerflow exhaust system, so may need to re-pitch to 62" depending on what the Powerflow does for performance.
Before the last round of speed mods, I was getting top speed of 162 mph indicated at 2790 rpm and about 1100 MSL with 62 inch pitch. (stock Cherokee 150C exhaust). After the hoerner wingtip installation and removing the wing tiedown rings, my low altitude cruise went up from 134 mph indicated to 138-141 indicated at 9.1 gph fuel burn, so am hoping the top speed will increase commensurately. With luck, I'll get a chance to check that tomorrow, weather permitting.
I'd like to add a couple more inches of pitch, but my static rpm (about 2295, depending upon density altitude) won't let me.
JimC
