Superior cylinder problem

[FLTENG]

Anybody experience the following. I installed a new Superior to replace a failed Lycoming cylinder in the # 3 position on O-360 A1D in my RV-7.
Completed 1 run-up of 10 minutes ( cowls off) for leak check then repeat with cowls on. All parameters in the green especially CHT (350 'F or below) and EGT (1200'f or below). However during engine runs experienced bottom spark plug fouling. After cleaning #3 bottom plug. Test flight duration was 1 circuit of 6 minutes. followed by approx 3 min taxi prior to shut down. On shutdown procedure it was discovered that # 3 was misfiring due fouled spark plug. This a attributed to excessive engine oil used in assembling and installing the cylinder. I then decided to remove the rocker cap cover of #3 to investigate further. It was then that I discovered that the Rocker shaft bushings, that are inserted in the each end of the rocker shafts, had partially melted. The supplier was as surprised as I was.
Cheers, Hugh

 

[Majorpayne317641]

Did you gap the rings? What did the barrel look like if you took it off after seeing the melted plastic end caps?

 

[Aden Rich]

You mean you melted the plastic end cap for the rocker arm shaft? Are the intake rocker arm and exhaust rocker arm switched? One has an oil hole and the other does not. The Intake arm has the hole in it. Parts number here for reference. IF its all Superior then all the P/N's would start with SL. Also, that rocker arm shaft should not rotate much once the pushrods are loaded up. I am assuming when you pulled the cylinder, you also pulled the hydraulic lifters and unloaded them, then reinstalled them and did the gap check and installed the correct pushrod size to get the unloaded, unsprung gap correct? Off the top of my head, it's like .026-.080?

 

[lr172]

Best guess is mfr error. Likely used the wrong plastic. Some plastics have a low melting point. I would take that superior problem over the washboarding all day long. There is really nothing that can go on up there to create enough heat to otherwise cause this problem; especially in 10 minutes.

 

[Dugaru]

Anybody experience the following. I installed a new Superior to replace a failed Lycoming cylinder in the # 3 position on O-360 A1D in my RV-7.
Completed 1 run-up of 10 minutes ( cowls off) for leak check then repeat with cowls on. All parameters in the green especially CHT (350 'F or below) and EGT (1200'f or below). However during engine runs experienced bottom spark plug fouling. After cleaning #3 bottom plug. Test flight duration was 1 circuit of 6 minutes. followed by approx 3 min taxi prior to shut down. On shutdown procedure it was discovered that # 3 was misfiring due fouled spark plug. This a attributed to excessive engine oil used in assembling and installing the cylinder. I then decided to remove the rocker cap cover of #3 to investigate further. It was then that I discovered that the Rocker shaft bushings, that are inserted in the each end of the rocker shafts, had partially melted. The supplier was as surprised as I was.
Cheers, Hugh

Your careful and systematic procedures paid off huge here. Well done.

 

[FLTENG]

Did you gap the rings? What did the barrel look like if you took it off after seeing the melted plastic end caps?

Yes rings gaped as per superior instructions. Barrel was fine no signs of overheating

 

[FLTENG]

You mean you melted the plastic end cap for the rocker arm shaft? Are the intake rocker arm and exhaust rocker arm switched? One has an oil hole and the other does not. The Intake arm has the hole in it. Parts number here for reference. IF its all Superior then all the P/N's would start with SL. Also, that rocker arm shaft should not rotate much once the pushrods are loaded up. I am assuming when you pulled the cylinder, you also pulled the hydraulic lifters and unloaded them, then reinstalled them and did the gap check and installed the correct pushrod size to get the unloaded, unsprung gap correct? Off the top of my head, it's like .026-.080?
View attachment 112201

Valve rocker clearance as per lycoming manual. Lifters unloaded. Currently waiting for new end caps. It is my belief that the caps are made of sub standard materials. All parts are Superior.

 

[ronrapp]

the caps are made of sub standard materials. All parts are Superior.

All evidence to the contrary.

 

[lr172]

Anybody experience the following. I installed a new Superior to replace a failed Lycoming cylinder in the # 3 position on O-360 A1D in my RV-7.
Completed 1 run-up of 10 minutes ( cowls off) for leak check then repeat with cowls on. All parameters in the green especially CHT (350 'F or below) and EGT (1200'f or below). However during engine runs experienced bottom spark plug fouling. After cleaning #3 bottom plug. Test flight duration was 1 circuit of 6 minutes. followed by approx 3 min taxi prior to shut down. On shutdown procedure it was discovered that # 3 was misfiring due fouled spark plug. This a attributed to excessive engine oil used in assembling and installing the cylinder. I then decided to remove the rocker cap cover of #3 to investigate further. It was then that I discovered that the Rocker shaft bushings, that are inserted in the each end of the rocker shafts, had partially melted. The supplier was as surprised as I was.
Cheers, Hugh

I could see the first plug fouling event from too much oil on assembly. The second time is a bit suspicious. Keep an eye on that. Fouled plugs during break in is not common

 

[mack55]

Anybody experience the following. I installed a new Superior to replace a failed Lycoming cylinder in the # 3 position on O-360 A1D in my RV-7.
Completed 1 run-up of 10 minutes ( cowls off) for leak check then repeat with cowls on. All parameters in the green especially CHT (350 'F or below) and EGT (1200'f or below). However during engine runs experienced bottom spark plug fouling. After cleaning #3 bottom plug. Test flight duration was 1 circuit of 6 minutes. followed by approx 3 min taxi prior to shut down. On shutdown procedure it was discovered that # 3 was misfiring due fouled spark plug. This a attributed to excessive engine oil used in assembling and installing the cylinder. I then decided to remove the rocker cap cover of #3 to investigate further. It was then that I discovered that the Rocker shaft bushings, that are inserted in the each end of the rocker shafts, had partially melted. The supplier was as surprised as I was.
Cheers, Hugh

I told superior about this problem in January. It should have been reported to the FAA. The button caps are melting at about 230 F. I did two top overhauls do to washboarding cylinders. They covered them under warranty but I had to do it twice. Then I found these melting. I replaced with old used ones. Check your sump screen. I found plastic that initially looked like fibers from a paper towel. Be sure to look at the inside of the screen as the plastic melts and passes through but gets snagged on the inside.

I warned several folks on Facebook. If you have superior cylinders replaced from around Nov 2025 you need to pull your rocker boxes.

 

[tthrew]

Thank you for posting this information - this is the first I’ve heard of the button cap issue. I too was caught up in the cylinder washboarding issue Superior had (covered under warranty). My last set of cylinders were installed in July, so I shouldn’t have the cap issue. I’ve already inspected the sump screen several times and didn’t notice anything, but I’ll do a visual inspection on the caps to be sure.

 

[Aden Rich]

Superior has really had a lot of issues with cylinders. We pulled cylinders off the PA-12 with 180hp. Didn't make it 150 hours and were toast, with too much blow by and high oil consumption. Had to get Lycomings since Superior had too much washboarding as mentioned above. I am amazed how good companies can start putting out junk products after making so many good parts for so many years. It can't be less expensive to make crappy parts and then loose the customer and have warranty issues to boot. Sorry you've had these issues too.

 

[Ironflight]

Superior has really had a lot of issues with cylinders. We pulled cylinders off the PA-12 with 180hp. Didn't make it 150 hours and were toast, with too much blow by and high oil consumption. Had to get Lycomings since Superior had too much washboarding as mentioned above. I am amazed how good companies can start putting out junk products after making so many good parts for so many years. It can't be less expensive to make crappy parts and then loose the customer and have warranty issues to boot. Sorry you've had these issues too.

The thing to remember about Superior is that they don’t actually make any parts - they find contractors to make them (to their specs) and then put Superior's name on them. So you really dont; know who made the cylinders. (Lycoming gets raw parts from contractors as well, but do more of the finishing machining and work….).

 

[Freemasm]

The thing to remember about Superior is that they don’t actually make any parts - they find contractors to make them (to their specs) and then put Superior's name on them. So you really dont; know who made the cylinders. (Lycoming gets raw parts from contractors as well, but do more of the finishing machining and work….).

and have been owned by Beijing for 15 years. Have any of their products increased in quality since? If so, please share.

 

[DennisRhodes]

I've had the rocker covers off a time or two on my Lyc 0320 in its 1000 hrs since overhaul ( no Superior Cylinders) but have never noticed PLASTIC end caps. I'm not an engine guy BUT Is that something I would find in mine???

 

[lr172]

I've had the rocker covers off a time or two on my Lyc 0320 in its 1000 hrs since overhaul ( no Superior Cylinders) but have never noticed PLASTIC end caps. I'm not an engine guy BUT Is that something I would find in mine???

Yes. Not really visible unless looking for it.

 

[Aden Rich]

I've had the rocker covers off a time or two on my Lyc 0320 in its 1000 hrs since overhaul ( no Superior Cylinders) but have never noticed PLASTIC end caps. I'm not an engine guy BUT Is that something I would find in mine???

Yes. Those keep the rocker arm shaft centered and also from moving to far one way or another. IF you don't have them, the rocker arm shaft will wear into the side wall of the valve cover.

 

[theduff]

After reading this post it got me to thinking. I had just delivered an L2A to my Son-in-Laws flight school and after checking my parts bin for the second set of rocker shafts and caps that I had ordered along with his and even though I had used factory new cylinders I had used Superior's rocker shaft caps. They're hanging the engine now so I have a little time yet which got me to thinking again and my inner Dan H decided to come out so a little test was forthcoming. The cap on the right is the Superior one which started to melt at about 280 degree F. The one on the left is a used one that was laying around the shop ( sorry don't know the manufacturer ) and it was untouched with aprox 325 degree F. heat from a heat gun. The Superior one appears to be an injection molded plastic while the used one appears to be made from delrin plastic. Im sure as word gets out we'll be hearing from Superior or the FAA. Sounds like Ill be pulling some valve covers off an L2A shortly !

 

[lr172]

Sounds like someone needs a little more oversight on their contract mfr’s.

 

[FLTENG]

I have spoken to Superior and was told I am not the only complainant and that the FAA has been informed of this problem.
Thank you for your input and opinions.

 

[pjc]

I've had the rocker covers off a time or two on my Lyc 0320 in its 1000 hrs since overhaul ( no Superior Cylinders) but have never noticed PLASTIC end caps. I'm not an engine guy BUT Is that something I would find in mine???

Depends on the age of your engine. Earlier (I don’t know the date) 320s simply used the rocker box covers to constrain the rocker shaft. The observation of metal on metal wear resulted in a design change to utilize the plastic end caps (and a shorter rocker shaft).

My 1970s era 320 does not use the plastic end caps.

PJC

 

[mack55]

After reading this post it got me to thinking. I had just delivered an L2A to my Son-in-Laws flight school and after checking my parts bin for the second set of rocker shafts and caps that I had ordered along with his and even though I had used factory new cylinders I had used Superior's rocker shaft caps. They're hanging the engine now so I have a little time yet which got me to thinking again and my inner Dan H decided to come out so a little test was forthcoming. The cap on the right is the Superior one which started to melt at about 280 degree F. The one on the left is a used one that was laying around the shop ( sorry don't know the manufacturer ) and it was untouched with aprox 325 degree F. heat from a heat gun. The Superior one appears to be an injection molded plastic while the used one appears to be made from delrin plastic. Im sure as word gets out we'll be hearing from Superior or the FAA. Sounds like Ill be pulling some valve covers off an L2A shortly !

I did this test back in December and notified Superior they had a major problem. I have never heard back... Unreal..

 

[mack55]

I have spoken to Superior and was told I am not the only complainant and that the FAA has been informed of this problem.
Thank you for your input and opinions.

Also, were you the first to have the washboarding with lycoming rings..? I know several folks they told that to over the past couple months.

 

[RV10inOz]

Not related to this thread, but there appears to be an emerging Superior cylinder issue that may not be widely understood yet, or maybe it is. Recently a C210 pilot down here had an overhaul, 6 new cylinders. Flies about 250 hours a year and at about 300 or so hours all 6 cylinders replaced under warranty no questions asked. The valve guides were all shot and leak downs exposed the problem.

Not sure who is paying the labour, but they are possibly going to cover that too. Sounds to me like there is a known but not publicised yet problem and they are trying to work out how big it is.

Not sure of this is much help but QC is something that eludes GA cylinder manufacturers at times. And Lycoming rod end bushes......And..........

 

[lr172]

Also, were you the first to have the washboarding with lycoming rings..? I know several folks they told that to over the past couple months.

That has been around for at least 6 months now.

 

[walkman]

I don't know why anybody buys anything from "Superior" at this point. They have a well proven track record of producing inferior products and then making it up by not standing behind them.

 

[FLTENG]

Also, were you the first to have the washboarding with lycoming rings..? I know several folks they told that to over the past couple months.

No known problem with wash-boarding

 

[theduff]

Note to Moderator this Thrust Button issue might be a good candidate for its own thread appropriately titled to separate it from the other Superior cylinder issues.

Well got some info to share with the group regarding Superiors rocker shaft Thrust Buttons and its NOT GOOD ! Had a chat with a friend who owns a large west coast engine shop regarding the Superior issue with the thrust buttons. He has multiple engines with this issue and when he forwarded his findings to Superior they refused to accept responsibility. He is now preparing documents for submittal to the FAA. He has had to partially tear down a few engines trying to determine how far the plastic has migrated through the engine and has not determined the full scope of damages to the engines. He sent me these photos which will give you some idea with what we're faced with.
To be completely accurate the part # were talking about is SL128902 and the lot # 250923-000028574. Both of our's came from this lot #. Other lots may be affected but his submittal to the FAA will be in reference to this particular lot #. I'm now convinced if you suspect you have Superior thrust bushings of recent vintage PLEASE PULL A VALVE COVER AND CHECK !! Catching it early may prevent you from dealing with a complete tear down.

 

[mack55]

I encountered this problem in January. I found plastic in my screen on the last oil change. Who knows where it went.. some pics of my test that I sent to superior.

 

[johnpaul44]

How many hours did you have on these thrust buttons? my recent overhaul used superior buttons have about 40 hours on it or so

 

[Majorpayne317641]

I just checked mine. They were from a local shop overhaul but superior brand back in 2023 and one brand new superior made the same year. Over 650hrs with no problems.