Hot cylinder

by **Todd Andrews** » Wed Jul 08, 2009 4:55 am

Hey everyone. I own a 260C and I'm having trouble keeping my #1 cylinder cool. It runs at least 25-35 degrees CHT warmer than any other cylinder. All cylinder run in the 375-390 but I have a hard time keeping cylinder #1 under 420 degrees. I've swapped CHT probes to make sure it wasn't a bad probe. I have gami's installed and all cylinder peak within 0.1 gal/hr so I don't think it is a fuel problem. My engine baffles aren't in the best condition but not that bad either. But you'd think if it was the baffles all cylinders on that side would be hot not the first one in the airflow. I'm wondering if I need to cut away some of the metal baffle that ramps up the air over the cylinder or even some of the scoop that brings air up above the cylinders to the airbox. The plane is new to me and the first thing I did was install an EDM 800 and been fighting with this ever since. Has anyone ever had experience with this?

by **9089P** » Wed Jul 08, 2009 4:23 pm

Hi Todd,

I think the baffling is the most likely. It is amazing what a few little problem areas can do to the overall picture. I had two small old sections of baffle and while ratty they looked to be doing the job. Mechanic said no and when replaced temps dropped 20-30 degrees.

Good luck, Don

by **N3322G** » Wed Jul 08, 2009 5:30 pm

Hi Todd,

Ditto on Don's baffle remarks. Mine were new but poorly installed, LoPresti 'tuned' them by plugging some holes and ta-da 20 degrees cooler as measured by EDM 760 - but this was on all cylinders.

I assume you've already cleaned the injectors and measured that the cht probe install is in the 'same' location on all the cylinders.

I also had a problem with hotter readings on the EDM Oil temp probe on the right engine which was corrected by improving the connection at the probe attachment point. Maybe a place for you to look also.

So these were on a Twin and I can't speak to which cylinders might run hotter on a single so hopefully others will chime in. I can say the Twin's #1and #2 cylinders always hit peak first.

If it isn't a measurement problem or cooling problem , then others will have to give you advice on a hot cylinder.

by **Alan Cheak** » Fri Jul 10, 2009 4:08 am

I have the same problem on my '63 250, only my problem cylinder is #6. Always run hotter than the other 5 and over 400 degrees is not un common. Its an overhauled cylinder and in 300 hours it will be time for an overhaul so I'll go with the reman game.

Alan Cheak

by **Todd Andrews** » Fri Jul 10, 2009 4:21 pm

Thanks guys, it just seems so odd that it's the first cylinder in the airflow. You'd think no matter how bad the baffles are the first cylinder would be the coolest. I know one of the tricks for winter ops is to put tape over the first cylinder to restrict airflow. My baffles on the right side seem to have a permanent ramp up then a piece of metal that goes an inch up the cylinder face. I'm sure this is designed to even out the temps of the cylinders on that side by restricting airflow over #1 and warm it up closer to that of #3 and #5. The other side doesn't have this piece of metal and runs considerably cooler than #4 and #6. I was wondering if that piece needs to be trimmed. On the prepurchase we identified this plane as always eating cylinders like candy. I flow it for 3 months the way the past owner told me to fly it before I installed the JPI. No indication of high temps on old guages. First take off with JPI alarms on cylinder temps 1 minute after take-off using previous owners power management. I now fly it differently and keep the alarms from occuring. I included two pictures of what I'm talking about.

by **9089P** » Fri Jul 10, 2009 5:14 pm

by **MULEFLY** » Sat Aug 01, 2009 12:31 am

by **Todd Andrews** » Sat Aug 01, 2009 12:50 am

by **Zach Grant L1011jock** » Sat Aug 01, 2009 4:00 pm

by **Ben Ayalon** » Mon Aug 03, 2009 1:01 pm

by **Zach Grant L1011jock** » Mon Aug 03, 2009 1:32 pm

by **Ben Ayalon** » Mon Aug 03, 2009 2:37 pm

by **Zach Grant L1011jock** » Mon Aug 03, 2009 4:52 pm

by **MULEFLY** » Mon Aug 03, 2009 5:17 pm

by **Ben Ayalon** » Tue Aug 04, 2009 10:57 am

Hot cylinder

Hot cylinder

Who is online