Topics

#1 cylinder still running hot. Not breaking in? Got any ideas?

Sam Hoskins
 

I installed a new cylinder and now with 6 hours on it, it still runs around 75 degrees hotter than the rest and I can't get it in line with the other cylinders. Shouldn't the rings be seated by now, or do I need to just keep flying it?

Here's the history:
O-200 New Superior Air parts cylinder. LyCon engines flow ported the cylinder and pre-installed a 9:1 piston to match the other three. When I installed it, I just withdrew the piston enough to insert the wrist pin, then stabbed the cylinder onto the engine.
My engine is fuel injected with a Bosch injector mounted on each intake tube. Electronic fuel injection and ignition is controlled by a RWS (now defunct) EC3 controller. I probably have 400 hours on this system.
I have a full plenum enclosing the cylinders.  You can see it here: http://samhoskins.blogspot.com/search?updated-max=2018-01-04T11:13:00-08:00
Previous to installing this new cylinder, the CHTs were relatively uniform.  Here is picture of the CHT with the previous cylinder: http://samhoskins.blogspot.com/search?updated-max=2018-01-04T11:13:00-08:00

I have ruled out the gasket type CHT sensor by swapping it with the #3 cylinder sensor.
I have ruled out the fuel injector by swapping the entire injector/intake tube assembly with the #3 tube assembly.
Twice, I have tried modifying the interior of the plenum by installing ramps to try and direct more air through the #1 cylinder.
I called LyCon and they didn't have any advice.
The EGT for that cylinder seems to be okay.

Here is my display from today's flight. 


So, what does the brain trust say?

Thanks.

astjp2
 

I would not be worried until you get 50 hours on the cylinder, 6 hours is barely just getting run in.

Jim Scoles
 

I would say just keep flying it. I thought it could take up to 25hrs to seat the rings. Its not past the redline in temps. I always do a preflight compression check whereby I pull the engine through at least 4 blades to make sure I don’t have a flat cylinder. The idea being that each blade feels roughly the same compression wise. As long as the compression is there and your temperature is stable even if it is higher than the others I would keep running it for another 15 to 20 hrs before I did anything radical like pull the cylinder.

My 2cents

Jim Scoles C 90


On Mar 5, 2020, at 3:38 PM, Sam Hoskins <sam.hoskins@...> wrote:

I installed a new cylinder and now with 6 hours on it, it still runs around 75 degrees hotter than the rest and I can't get it in line with the other cylinders. Shouldn't the rings be seated by now, or do I need to just keep flying it?

Here's the history:
O-200 New Superior Air parts cylinder. LyCon engines flow ported the cylinder and pre-installed a 9:1 piston to match the other three. When I installed it, I just withdrew the piston enough to insert the wrist pin, then stabbed the cylinder onto the engine.
My engine is fuel injected with a Bosch injector mounted on each intake tube. Electronic fuel injection and ignition is controlled by a RWS (now defunct) EC3 controller. I probably have 400 hours on this system.
I have a full plenum enclosing the cylinders.  You can see it here: http://samhoskins.blogspot.com/search?updated-max=2018-01-04T11:13:00-08:00
Previous to installing this new cylinder, the CHTs were relatively uniform.  Here is picture of the CHT with the previous cylinder: http://samhoskins.blogspot.com/search?updated-max=2018-01-04T11:13:00-08:00

I have ruled out the gasket type CHT sensor by swapping it with the #3 cylinder sensor.
I have ruled out the fuel injector by swapping the entire injector/intake tube assembly with the #3 tube assembly.
Twice, I have tried modifying the interior of the plenum by installing ramps to try and direct more air through the #1 cylinder.
I called LyCon and they didn't have any advice.
The EGT for that cylinder seems to be okay.

Here is my display from today's flight. 
<CHT.jpg>


So, what does the brain trust say?

Thanks.

Keith Hodge
 

The cylinder being new is probably working harder than the others.

 

 

From: main@SmallContinentalEngines.groups.io <main@SmallContinentalEngines.groups.io> On Behalf Of Jim Scoles
Sent: 05 March 2020 21:22
To: main@smallcontinentalengines.groups.io
Subject: Re: [SmallContinentalEngines] #1 cylinder still running hot. Not breaking in? Got any ideas?

 

I would say just keep flying it. I thought it could take up to 25hrs to seat the rings. Its not past the redline in temps. I always do a preflight compression check whereby I pull the engine through at least 4 blades to make sure I don’t have a flat cylinder. The idea being that each blade feels roughly the same compression wise. As long as the compression is there and your temperature is stable even if it is higher than the others I would keep running it for another 15 to 20 hrs before I did anything radical like pull the cylinder.

 

My 2cents

 

Jim Scoles C 90



On Mar 5, 2020, at 3:38 PM, Sam Hoskins <sam.hoskins@...> wrote:

I installed a new cylinder and now with 6 hours on it, it still runs around 75 degrees hotter than the rest and I can't get it in line with the other cylinders. Shouldn't the rings be seated by now, or do I need to just keep flying it?

Here's the history:
O-200 New Superior Air parts cylinder. LyCon engines flow ported the cylinder and pre-installed a 9:1 piston to match the other three. When I installed it, I just withdrew the piston enough to insert the wrist pin, then stabbed the cylinder onto the engine.
My engine is fuel injected with a Bosch injector mounted on each intake tube. Electronic fuel injection and ignition is controlled by a RWS (now defunct) EC3 controller. I probably have 400 hours on this system.
I have a full plenum enclosing the cylinders.  You can see it here: http://samhoskins.blogspot.com/search?updated-max=2018-01-04T11:13:00-08:00
Previous to installing this new cylinder, the CHTs were relatively uniform.  Here is picture of the CHT with the previous cylinder: http://samhoskins.blogspot.com/search?updated-max=2018-01-04T11:13:00-08:00

I have ruled out the gasket type CHT sensor by swapping it with the #3 cylinder sensor.
I have ruled out the fuel injector by swapping the entire injector/intake tube assembly with the #3 tube assembly.
Twice, I have tried modifying the interior of the plenum by installing ramps to try and direct more air through the #1 cylinder.
I called LyCon and they didn't have any advice.
The EGT for that cylinder seems to be okay.

Here is my display from today's flight. 

<CHT.jpg>



So, what does the brain trust say?

Thanks.

Sam Hoskins
 

Thanks guys. Sounds like I may have been jumping the gun in my expectations. I'll keep on flying and will report back later.

Sam 

On Thu, Mar 5, 2020, 2:38 PM Sam Hoskins via Groups.Io <sam.hoskins=gmail.com@groups.io> wrote:
I installed a new cylinder and now with 6 hours on it, it still runs around 75 degrees hotter than the rest and I can't get it in line with the other cylinders. Shouldn't the rings be seated by now, or do I need to just keep flying it?

Here's the history:
O-200 New Superior Air parts cylinder. LyCon engines flow ported the cylinder and pre-installed a 9:1 piston to match the other three. When I installed it, I just withdrew the piston enough to insert the wrist pin, then stabbed the cylinder onto the engine.
My engine is fuel injected with a Bosch injector mounted on each intake tube. Electronic fuel injection and ignition is controlled by a RWS (now defunct) EC3 controller. I probably have 400 hours on this system.
I have a full plenum enclosing the cylinders.  You can see it here: http://samhoskins.blogspot.com/search?updated-max=2018-01-04T11:13:00-08:00
Previous to installing this new cylinder, the CHTs were relatively uniform.  Here is picture of the CHT with the previous cylinder: http://samhoskins.blogspot.com/search?updated-max=2018-01-04T11:13:00-08:00

I have ruled out the gasket type CHT sensor by swapping it with the #3 cylinder sensor.
I have ruled out the fuel injector by swapping the entire injector/intake tube assembly with the #3 tube assembly.
Twice, I have tried modifying the interior of the plenum by installing ramps to try and direct more air through the #1 cylinder.
I called LyCon and they didn't have any advice.
The EGT for that cylinder seems to be okay.

Here is my display from today's flight. 


So, what does the brain trust say?

Thanks.

Dale Severs
 

It could be any intake valves leaking causing one cylinder to run hot.

On Thu, Mar 5, 2020 at 3:11 PM astjp2 via Groups.Io <astjp2=yahoo.com@groups.io> wrote:
I would not be worried until you get 50 hours on the cylinder, 6 hours is barely just getting run in.

Dale Severs
 

Do a compression test and listen for air flow in the intake manifold

On Thu, Mar 5, 2020 at 3:11 PM astjp2 via Groups.Io <astjp2=yahoo.com@groups.io> wrote:
I would not be worried until you get 50 hours on the cylinder, 6 hours is barely just getting run in.

Dale Severs
 

check the valve clearance as the push rods come in different lengths

On Thu, Mar 5, 2020 at 3:11 PM astjp2 via Groups.Io <astjp2=yahoo.com@groups.io> wrote:
I would not be worried until you get 50 hours on the cylinder, 6 hours is barely just getting run in.

Mike Papenthien
 

I also have Millenials on my O-200 with 9:1 pistons (320 hrs now) and it took a long time for everything to break in completely... well over 50 hrs! 
You’ll want to run it strong and long to improve on the process as my flights typically aren’t very long. It would be helpful to run 1.5+ hrs at a time. 

On Mar 6, 2020, at 8:34 AM, Dale Severs <Routedmail@...> wrote:


check the valve clearance as the push rods come in different lengths

On Thu, Mar 5, 2020 at 3:11 PM astjp2 via Groups.Io <astjp2=yahoo.com@groups.io> wrote:
I would not be worried until you get 50 hours on the cylinder, 6 hours is barely just getting run in.

Michael Quinn
 

Agree with break in time need - you are running a non detergent break in oil?  What break in methods are you using (everyone seems to be different) ?

What I saw on mine is it stayed high on CHT for 10-15 hrs. then "magically" dropped in one flight to "normal" (I was expecting a gradual decline as rings "found" their home)

Sam Hoskins
 

Using the standard break-in recommended by Superior air parts. Mineral oil, minimum ground run, burying throttle while in flight, Etc.

In the past, my engines have have the CHT come down within the first hour or so. This is different for me and the comments I've had from you folks rest my mind a bit that the installations okay and that I just need to fly.

Sam 

On Fri, Mar 6, 2020, 11:48 AM Michael Quinn <mquinn6@...> wrote:
Agree with break in time need - you are running a non detergent break in oil?  What break in methods are you using (everyone seems to be different) ?

What I saw on mine is it stayed high on CHT for 10-15 hrs. then "magically" dropped in one flight to "normal" (I was expecting a gradual decline as rings "found" their home)