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Re: O-320 Oil Cooler Baffle STC
Let us know how that works out next summer.
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Re: O-320 Oil Cooler Baffle STC
Wanted to add that a well running O320 properly operated stays cool in all manor of baffle conditions: the good, the bad, and the ugly.
Back in my VW engine days everyone wanted me to add a bigger oil pump or an extra cooler when the problem had nothing to do with oil cooling. Some people were going to blow up an air cooled engine regardless, smoked a type II myself drafting a semi at over 70mph for almost three hours.
Mostly there was another problem and the engine was just used up.
Rocket
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Re: O-320 Oil Cooler Baffle STC
Just want to point out that oil temp will trend with but not directly reflect the engine cylinder head temps. The other issue with higher oil temps is you may need to increase you oil pressure if you run in the above 200 degree range. Just be careful you do not have too high of a pressure with cold oil.
DENNY
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Re: O-320 Oil Cooler Baffle STC
Originally Posted by
rocket
Wanted to add that a well running O320 properly operated stays cool in all manor of baffle conditions: the good, the bad, and the ugly.
I think it has more to do with your lattitude. Mine had no cooling issues until I brought it south and temps warmed up. I think it's running pretty well, and its only ~170 hrs old. Baffle seals are crap though.
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Administrator
Re: O-320 Oil Cooler Baffle STC
Originally Posted by
CamTom12
I think it has more to do with your lattitude. Mine had no cooling issues until I brought it south and temps warmed up. I think it's running pretty well, and its only ~170 hrs old. Baffle seals are crap though.
I agree after having high oil temps on a new engine. Learned a lot when we installed a manometer and started doing some testing. A lot of info in this thread.
http://www.supercub.org/forum/showth...ure-Experience
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Re: O-320 Oil Cooler Baffle STC
Originally Posted by
Homer Landreth
I certainly like the aspect of " if the Oil Temp stays within acceptable parameters then that is all that matters." That is uncommon simplicity from the FAA.
Anyway, I never did really like the two oil coolers on my plane and since I have finally reached the status of "somewhat retired" I think I will take the baffle mounted one off in my new found spare time.
With a huge "Mea Culpa" , I change my position and attitude on this subject.
I went to the Super Cub WEB site that Steve referenced (Thank You Sir for that) and read the entire train and found it interesting and impressive to say the least. Now, copying from that thread, I find complete agreement with this Gentleman's statement:
Bear in mind that Lycoming's certified CHT limit is 500 *F. We all know that a continual operation above 400*F will reduce cylinder life considerably. So, as long as Piper's test data fell below this 500*F limit the certification requirements would have been satisfied. We, collectively should strive to improve the cooling so as to fall below the 400* threshold during most operations. This is not difficult, but there should be an STC issued for the "new" baffle system. The STC does not need a FAA-PMA if there are only drawings issued. The parts could be built as "owner built parts". Any parts built for sale would require a FAA-PMA.
In view of the fact that the Super Cub thread ended with the cause of the high oil temperature being Baffling and Air Flow, and in consideration of the intent of the above statement, I change my previous thoughts and statements to be having total amazement and disbelief that the FAA granted Field Approvals (337s previously attached) and subsequently an STC, for the relocating of the Oil Cooler WITHOUT (emphasis on the word WITHOUT) requiring a complete drawing detail and test data to substantiate the "new" baffling arrangement.
Anyway I am certainly going to work up different paperwork for my plane and will take a lot harder look at airworthiness of any "modified" baffling on future annuals I conduct.
Thanks again to Steve for the reference to that test activity.
Homer
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Administrator
Re: O-320 Oil Cooler Baffle STC
The STC for the rear mounted oil cooler had to go through the entire flight test program for noise, cooling and performance as well as an installation conformity inspection along with approved drawing etc.
Bear in mind that Lycoming's certified CHT limit is 500 *F. We all know that a continual operation above 400*F will reduce cylinder life considerably. So, as long as Piper's test data fell below this 500*F limit the certification requirements would have been satisfied. We, collectively should strive to improve the cooling so as to fall below the 400* threshold during most operations. This is not difficult, but there should be an STC issued for the "new" baffle system. The STC does not need a FAA-PMA if there are only drawings issued. The parts could be built as "owner built parts". Any parts built for sale would require a FAA-PMA.
This statement is in response to the modifications Fobjob made to his baffles. Not the STC for moving the cooler. You would have to know Fobjob and see his airplane to really understand I think.
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Re: O-320 Oil Cooler Baffle STC
Originally Posted by
Steve Pierce
The STC for the rear mounted oil cooler had to go through the entire flight test program for noise, cooling and performance as well as an installation conformity inspection along with approved drawing etc.
This statement is in response to the modifications Fobjob made to his baffles. Not the STC for moving the cooler. You would have to know Fobjob and see his airplane to really understand I think.
My reference is to the action of altering the baffle structure. The above citation was in consideration of CHT, the referenced STC and Field approvals for the Oil Cooler re-location in consideration of Oil Temperature also altered the baffle structure. Same activity, but different purpose yet sympathetic dependencies exist. As such I developed the opinion that why the baffle structure was modified is irrelevant, the new modification for oil temperature should have had the same attention to documenting the exact equipment content, the detailed required testing and detailed documentation of the alteration of the baffles that the CHT purposes had. Actually, the liberal aspect of the Field Approval is slightly more acceptable than the STC, because it applies only to the documented aircraft. The STC approval applies to other than a that single aircraft. I noted in the thread what there seemed to be different aircraft TMS and different Exhaust systems and different component location, which may result in one or more variants to the modification that is not controlled, one being no specific detail as to where exactly to locate the Oil Cooler. I just developed the feeling that if I observed those noted issues, I would want a little more clarity on how the modification was done, and how it was verified as to whether it works or not.
Last edited by Homer Landreth; 01-28-2016 at 04:09 PM.
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Administrator
Re: O-320 Oil Cooler Baffle STC
You lost me Homer. Are we talking about the modification to the baffle to install the oil cooler?
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Re: O-320 Oil Cooler Baffle STC
Originally Posted by
Steve Pierce
You lost me Homer. Are we talking about the modification to the baffle to install the oil cooler?
I guess I didn't get all of that out very clear. Basically what I am saying is that in the evolution of heat, heat can be caused by poor oil cooling, or oil can be overheated by poor airflow around the engine components. (Kind of a chicken or egg question, which came first?) Therefore, I think that baffle modification beyond the OEM layout needs better description of why it was done, how to do it, and documented delta test results. Basically, I got over verbose about saying that after following that thread on the SC site I got a "born again" moment and that In the future, if I see a modified baffle structure, I am going to ask a group of questions about CHT, Oil Temps, Engine History, and Documentation. I am going to want to know what I don't know about the mod.
Thanks for your time in trying to follow my circuitous verbosity.
Homer
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