arizona baffle

Any DA40 related topics

Moderators: Rick, Lance Murray

User avatar
blsewardjr
4 Diamonds Member
4 Diamonds Member
Posts: 485
Joined: Tue Jul 26, 2011 11:19 pm
First Name: Bernie
Aircraft Type: DA40
Aircraft Registration: N377DS
Airports: KCHO
Has thanked: 118 times
Been thanked: 146 times

Re: arizona baffle

Post by blsewardjr »

My DA40 has had a hotter #1 cylinder (anywhere from 10-30 degrees from the next hottest) for years. I recently put on a new #1 cylinder and the problem, if anything, gotten worse. (The new cylinder has 45 hours on it and the temp is 20-30 degrees hotter than the next hottest cylinder across a range of fuel flows ROP to LOP at 65%). If the #1 temp was within a good temp range I might not care, but it now runs 405-420 on climb out and 400+ at book ROP settings for 65% and 75%. (LOP it runs cool enough, 370-380, but I'd like to be able to go fast if desired.) I've tried everything I've seen on this forum (Arizona baffle, sealing up all holes, addressing the waves in the top flexible baffles, tightening the baffles to cylinders, mag timing, PowerFlow, fine wire plugs, GAMIs, etc.) It seems to me that the only thing left is to try cutting down the interior part of the Arizona baffle that partially covers the #1 cylinder, which is visible in Steve's post above. My IA discussed it with Diamond, who said that it might help but would increase the #3 CHT. That would be ok because it's the coldest cylinder. He's a little reluctant to do it and asked me to run it by you guys. I was wondering if anyone else has done it or has any other ideas. If so, that might help persuade. Thanks. Bernie
Bernie Seward, IR, AGI
2003 DA40 N377DS
KCHO Charlottesville, VA
User avatar
Rich
5 Diamonds Member
5 Diamonds Member
Posts: 4592
Joined: Mon Aug 30, 2010 12:40 pm
First Name: Rich
Aircraft Type: DA40
Aircraft Registration: N40XE
Airports: S39 Prineville OR
Has thanked: 145 times
Been thanked: 1180 times

Re: arizona baffle

Post by Rich »

blsewardjr wrote: Tue Mar 24, 2020 9:12 pm My DA40 has had a hotter #1 cylinder (anywhere from 10-30 degrees from the next hottest) for years. I recently put on a new #1 cylinder and the problem, if anything, gotten worse. (The new cylinder has 45 hours on it and the temp is 20-30 degrees hotter than the next hottest cylinder across a range of fuel flows ROP to LOP at 65%). If the #1 temp was within a good temp range I might not care, but it now runs 405-420 on climb out and 400+ at book ROP settings for 65% and 75%. (LOP it runs cool enough, 370-380, but I'd like to be able to go fast if desired.) I've tried everything I've seen on this forum (Arizona baffle, sealing up all holes, addressing the waves in the top flexible baffles, tightening the baffles to cylinders, mag timing, PowerFlow, fine wire plugs, GAMIs, etc.) It seems to me that the only thing left is to try cutting down the interior part of the Arizona baffle that partially covers the #1 cylinder, which is visible in Steve's post above. My IA discussed it with Diamond, who said that it might help but would increase the #3 CHT. That would be ok because it's the coldest cylinder. He's a little reluctant to do it and asked me to run it by you guys. I was wondering if anyone else has done it or has any other ideas. If so, that might help persuade. Thanks. Bernie
One thing you might check is something I found with my #3 cylinder after installing the Surefly. The scat tubing that leads back to the battery had become routed below that cylinder head, impeding airflow in the area where the CHT probe is located. My #3 CHTs were nibbling at 400 deg in cruise. I did some finagling to keep the tubing away from the cylinder head and voila! back to normal. You might check for some similar obstruction below #1. #3 has been and still is my hottest cylinder, but not by much. My coldest cylinder has long been #4, and the overall pattern of CHTs follows EGTs.
2002 DA40-180: MT, PowerFlow, 530W/430W, KAP140, ext. baggage, 1090 ES out, 2646 MTOW, 40gal., Surefly, Flightstream 210, Orion 600 LED, XeVision, Aspen E5
User avatar
Rich
5 Diamonds Member
5 Diamonds Member
Posts: 4592
Joined: Mon Aug 30, 2010 12:40 pm
First Name: Rich
Aircraft Type: DA40
Aircraft Registration: N40XE
Airports: S39 Prineville OR
Has thanked: 145 times
Been thanked: 1180 times

Re: arizona baffle

Post by Rich »

Rich wrote: Thu Mar 05, 2020 9:26 pm … I recently found a problem with #4 CHT reading being high caused by the positioning of the SCAT tubing that runs below the right side cylinders and cools the battery compartment.
I incorrectly said “#4 CHT”. In fact it was #3 CHT that was a problem. #3 is on the right side, whereas #4 is on the left. :oops:
2002 DA40-180: MT, PowerFlow, 530W/430W, KAP140, ext. baggage, 1090 ES out, 2646 MTOW, 40gal., Surefly, Flightstream 210, Orion 600 LED, XeVision, Aspen E5
Post Reply