Posted 24 Dec 2017 TSoftware, I was cruising through old posts and found this thread. Back two months ago I went through exactly what you went through with the prop pitch / rpm / EGT. First I found that my water temp and EGT gauges were off. Both were older Westach gauges. I then found out my RPM gauge was not reading right. I replaced it with a new tach and added a Tiny Tach also. The newer Tiny Tach has a timer on it so it came in useful as an extra timer in the cockpit. After all the gauges were working I was still getting high EGT’s. To makes life harder someone had placed the EGT probes in the wrong location on the Exhaust Manifold. They are suppose to be 1 1/2 and 1 5/8 inches away from the manifold flange. (depending on what side of the Exhaust the probes were mounted to). My probes were placed at 3 1/2 inches out. After I got all this figured out then came the pitch setting. The factory said I should be at 14 degrees. Everything I read said to set it at 6200 to 6300 static. This would not work for my set up. After four prop adjustments I finally got it to cool to the 1150 range in cruise. I’m running a 64 inch three blade GSC. I’m set at 16 degrees of pitch. 2.58 to 1. My static ended up at 5850 and my WOT straight and level rpm at 6700. Seems from reading through this site that there are many variables. Just figured I would share mine too. Share this post Link to post Share on other sites
Posted 24 Dec 2017 TSoftware, I was cruising through old posts and found this thread. Back two months ago I went through exactly what you went through with the prop pitch / rpm / EGT. First I found that my water temp and EGT gauges were off. Both were older Westach gauges. I then found out my RPM gauge was not reading right. I replaced it with a new tach and added a Tiny Tach also. The newer Tiny Tach has a timer on it so it came in useful as an extra timer in the cockpit. After all the gauges were working I was still getting high EGT’s. To makes life harder someone had placed the EGT probes in the wrong location on the Exhaust Manifold. They are suppose to be 1 1/2 and 1 5/8 inches away from the manifold flange. (depending on what side of the Exhaust the probes were mounted to). My probes were placed at 3 1/2 inches out. After I got all this figured out then came the pitch setting. The factory said I should be at 14 degrees. Everything I read said to set it at 6200 to 6300 static. This would not work for my set up. After four prop adjustments I finally got it to cool to the 1150 range in cruise. I’m running a 64 inch three blade GSC. I’m set at 16 degrees of pitch. 2.58 to 1. My static ended up at 5850 and my WOT straight and level rpm at 6700. Seems from reading through this site that there are many variables. Just figured I would share mine too. you running a 64 or 68" 64 is pretty darn small for the plane you have. There are other variables on the midrange EGTS as well, you can play with the tuning to get everything where you want it. I use the inflight mixture and the IFA to keep everything in the green and happy. When just running the ground adjustable I did as much as I could with prop pitch, then still have to use the in flight mixtures depending on altitude and air temps. For people who are dealing with out of control EGTS with "normal" prop pitch settings I highly suggest going to an in flight mixture adjust like the hacman. Share this post Link to post Share on other sites
Posted 24 Dec 2017 I would like to move to a 70 inch prop. I flew a Powefin on a similar set up and it was really smooth and made good thrust. The Hacman system is a must from talking to people who run them and fly various altitudes. I probably won’t go with a IFA. 1 person likes this Share this post Link to post Share on other sites
Posted 8 Nov 2018 (edited) Cowlove came up with a really neat & simple version of the hacman system using an inexpensive, small 12V diaphragm vacuum pump. These things are used in some portable medical devices, and are surprisingly easy to find online. My greyhead's carbs have no drillings for throat vacuum, to be used as a source, so the vac pump was much easier to do. I have installed his system on my engine, have used it to shut down the engine, but have not had the opportunity to check it out at altitude. Cowlove shared a pic of his instrument panel with the Catalina at 14kft! A nice side benefit is the ability to smooth out idle at any density altitude. FWIW. Edited 8 Nov 2018 by Turbo 1 person likes this Share this post Link to post Share on other sites