Page 4 of 4 FirstFirst ... 234
Results 121 to 156 of 156

Thread: Oil temperature question

  1. #121
    Schwarz's Avatar
    Join Date
    Oct 2016
    Location
    Abilene, Texas
    Posts
    40
    Post Thanks / Like
    I donít know, I didnít torque it.


    Sent from my iPhone using SuperCub.Org
    Wes Schwarz

  2. #122

    Join Date
    May 2014
    Posts
    558
    Post Thanks / Like
    Quote Originally Posted by Schwarz View Post
    I don’t know, I didn’t torque it.


    Sent from my iPhone using SuperCub.Org

    Measure as following image describes. Worn-in bushings are hard to accurately torque.
    Think I’d feel better about using drilled bolts and castellated nuts for that application as well.

    Then mount your cooler up front and save a lot of fabricating and experimenting. Cylinders need all the air they can get.


    Click image for larger version. 

Name:	C58787FC-09A8-47DE-9927-88AA996154AE.png 
Views:	56 
Size:	201.6 KB 
ID:	44129

  3. #123
    Schwarz's Avatar
    Join Date
    Oct 2016
    Location
    Abilene, Texas
    Posts
    40
    Post Thanks / Like
    What picture/motor mount are yíall talking about?


    Sent from my iPhone using SuperCub.Org
    Wes Schwarz

  4. #124

    Join Date
    May 2014
    Posts
    558
    Post Thanks / Like
    Click image for larger version. 

Name:	EC7C2969-AB8C-4AE1-940D-ADA6A4320F42.jpeg 
Views:	56 
Size:	115.7 KB 
ID:	44131

  5. #125
    Schwarz's Avatar
    Join Date
    Oct 2016
    Location
    Abilene, Texas
    Posts
    40
    Post Thanks / Like
    Oh ok, are yíall noticing it because it has a lock nut and not a cotter pin? Iím not sure, like I said, I didnít install it.


    Sent from my iPhone using SuperCub.Org
    Wes Schwarz

  6. #126
    Farmboy's Avatar
    Join Date
    Jan 2016
    Location
    Glens Falls, NY
    Posts
    2,077
    Post Thanks / Like
    Wes, Iím very familiar with things running hotter than normal. Let me know when I can pick it up. Iíll bring it up north for a year and see if that fixes it. If so, Iíll send a telegram letting you know that itís fixed.

    Peter.


    Sent from my iPhone using SuperCub.Org
    Likes kestrel liked this post

  7. #127
    Schwarz's Avatar
    Join Date
    Oct 2016
    Location
    Abilene, Texas
    Posts
    40
    Post Thanks / Like
    Thanks Peter, Iíll certainly keep you in mind!


    Sent from my iPhone using SuperCub.Org
    Wes Schwarz
    Likes Farmboy liked this post

  8. #128

    Join Date
    Feb 2002
    Location
    don
    Posts
    691
    Post Thanks / Like
    Love the Pacer!
    Thanks CamTom12 thanked for this post

  9. #129
    Schwarz's Avatar
    Join Date
    Oct 2016
    Location
    Abilene, Texas
    Posts
    40
    Post Thanks / Like
    Ok had a chance this morning to do some testing, used the digital manometer to check air flow through the cowling.

    Upper test point


    Routing through baffling


    Lower test point, tie strapped to motor mount,




    Meter reading,


    So it seems that the difference in pressure from upper to lower isn't enough. What are some ways to increase airflow? Sea plane lip is one I've heard recommended, any other ways? Here is a pic or two of my lower cowling area.





    Sorry for the fuzzy pic, what else would you check?

    Thanks.


    Wes Schwarz

  10. #130
    CamTom12's Avatar
    Join Date
    Jul 2015
    Location
    Huntsville, AL
    Posts
    635
    Post Thanks / Like
    Another test you can do is to unplug first one, then the other tube from the meter to compare upper cowling and lower cowling pressure with static. It helps to have your window or door open for this, otherwise cabin pressure is usually slightly lower than actual static air pressure.

    Another note, my meter "normalizes" its pressure differential when I turn it on. This means I have to either turn it on before I crank the motor and keep it awake until I'm ready to take my reading, or I have to disconnect both tubes before I boot it up in-flight. Otherwise I get erroneous pressure differential readings with mine. Not sure if yours works the same but it looks similar to mine.

    Go out to the hangar at night and stick a drop-light in your lower cowl. Look around the upper cowl for any light escapes. You will might need a mirror to look through the air inlets with the upper cowl doors closed. That'll check your baffles and rubber seals.

    If your baffles and rubber seals are tight, you're either introducing high pressure air into your lower cowling from the free-stream air or you're not evacuating the lower cowl well. From the pictures I'd bet your lower cowl exit is doing both. A seaplane lip will help evacuate the lower cowl and keep the free-stream air out.

    A good way to visualize what you need is to take a picture of your airplane from the side and rotate it so that your wing roots are angled like they would be in level flight. Then you need enough lip to create a horizontal "shadow" over your lower cowl exit hole that extends back past where your lower cowl exit hole ends.
    Thanks Schwarz thanked for this post
    Likes Schwarz liked this post

  11. #131
    skywagon8a's Avatar
    Join Date
    Mar 2008
    Location
    SE Mass
    Posts
    9,153
    Post Thanks / Like
    Quote Originally Posted by Schwarz View Post
    ..So it seems that the difference in pressure from upper to lower isn't enough. What are some ways to increase airflow? Sea plane lip is one I've heard recommended, any other ways? Here is a pic or two of my lower cowling area.





    Sorry for the fuzzy pic, what else would you check?

    Thanks.
    Try a lower lip such as this, on this Backcountry Cub. You could attach it to the grey portion of your lower cowl.



    Also, how large an opening do you have on your side cowls when they are closed. It should be 2-1/2" to 3" measured at the mid widest point. There is a lot of heat which comes out of these side cowls. I don't have an interior in mine. When I place my hand on the inside of the fabric just below the door it is always very warm. I believe that it actually helps to heat the cabin in cold weather.
    This engine is an IO-360 (180 hp) with no cooling issues. The CHT will exceed 400 on a very hot day. This is easily resolved by enriching the mixture. Normal highs are about 380 CHT.

    Another view of the lip on the inside. Click image for larger version. 

Name:	SMITHCUBPetes020.jpg 
Views:	54 
Size:	84.4 KB 
ID:	44207
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	SMITHCUBPetes015.jpg 
Views:	43 
Size:	69.0 KB 
ID:	44206  
    Last edited by skywagon8a; 08-24-2019 at 04:47 PM.
    N1PA
    Thanks Schwarz thanked for this post
    Likes Schwarz liked this post

  12. #132

    Join Date
    May 2014
    Posts
    558
    Post Thanks / Like
    Wes,
    at cub speeds you’d be doing well if you get in the high 3’s on the manometer, (you’re calibrated to “ of water correct?)
    For fun, on your next test run point the nose down till you’re about 115 kts and see what the differential pressure does, because that’s how fast you need to be going, according to lycoming, to meet their recommended 5”H2O.
    As cam Tom suggested, check baffling, then a bunch of little mods all start adding up. Lots of info in earlier threads.
    But start with:
    Timing
    Fuel (too lean)
    Baffling

    I mentioned this earlier, may or may not apply:
    My last build I slammed the cowl down as close as the ring gear would allow, Ive seen others do this too,
    improves visibility over the nose. Well it also significantly disrupts airflow entering cowl inlets, To the tune of about 20 deg
    on the back cylinders.
    Thanks Schwarz thanked for this post
    Likes Schwarz liked this post

  13. #133
    Schwarz's Avatar
    Join Date
    Oct 2016
    Location
    Abilene, Texas
    Posts
    40
    Post Thanks / Like
    Also, how large an opening do you have on your side cowls when they are closed. It should be 2-1/2" to 3" measured at the mid widest point.
    It's a bit shy of 2.5-3.0 inches,





    Then you need enough lip to create a horizontal "shadow" over your lower cowl exit hole that extends back past where your lower cowl exit hole ends.
    CamTom, can you explain, not sure what your saying.

    (youíre calibrated to ď of water correct?)
    Yep, but I may need to go fly it again and play with it a bit, I didn't turn the manometer on until I was sitting in the plane and it was running, I think, but not sure, I hooked up the lines to the manometer after engine start.

    Thanks for the replies.



    Wes Schwarz

  14. #134

    Join Date
    Jan 2007
    Posts
    1,610
    Post Thanks / Like
    It looks like you have a outflow problem. This is not uncommon even in stock cubs. The experimental kit makers seem to have a lot of trouble with understanding the need for good air flow. The first thing I would do is a large seaplane lip because it is pretty easy to do. I would say your cheeks are too small but it is a lot more work to replace them and get the paint right so hold off if you can. I would also chase the possibility of air trapped in the cooler ideal mentioned earlier. Have you checked the timing/internal timing of the mags? That is a inexpensive thing to do. If you can afford a 4 cylinder eg/cht you could look at building ramps on the front cylinders but I would not do that unless you can monitor all 4. Thanks for the feedback so far. I am sure you will get this fixed just not sure how much work it will be.
    DENNY
    Thanks Schwarz thanked for this post
    Likes Schwarz, Bowie liked this post

  15. #135
    CamTom12's Avatar
    Join Date
    Jul 2015
    Location
    Huntsville, AL
    Posts
    635
    Post Thanks / Like

    Oil temperature question

    Quote Originally Posted by Schwarz View Post
    CamTom, can you explain, not sure what your saying.
    Hereís a not-so-great pictorial example:



    If you were to shine a light from directly in front of the plane, my new lip (outlines in red) would create a shadow that extends past the opening in my lower cowl exit (also outlined in red... maybe I should have used different colors, haha).

    It made a pretty big difference in my lower cowling pressure as compared to static pressure.
    Likes Bowie liked this post

  16. #136
    BC12D-4-85's Avatar
    Join Date
    Feb 2016
    Location
    Fairbanks, AK.
    Posts
    1,526
    Post Thanks / Like
    Wes is there a through opening around the air filter element to the rear cowl exit? It would seem that blocking that passage just behind the air filter (or?) might lower the air pressure below the engine. Adding ram air to that area might be raising it is my assumption. Didn't Piper seal that passage?

    Gary

  17. #137
    Schwarz's Avatar
    Join Date
    Oct 2016
    Location
    Abilene, Texas
    Posts
    40
    Post Thanks / Like
    Hereís a not-so-great pictorial example:



    If you were to shine a light from directly in front of the plane, my new lip (outlines in red) would create a shadow that extends past the opening in my lower cowl exit (also outlined in red... maybe I should have used different colors, haha).

    It made a pretty big difference in my lower cowling pressure as compared to static pressure.
    Gotcha, Thanks.

    Wes is there a through opening around the air filter element to the rear cowl exit? It would seem that blocking that passage just behind the air filter (or?) might lower the air pressure below the engine. Adding ram air to that area might be raising it is my assumption. Didn't Piper seal that passage?

    Gary
    Good question, I'll have to research that, thanks.
    Wes Schwarz
    Thanks pfm thanked for this post

  18. #138
    BC12D-4-85's Avatar
    Join Date
    Feb 2016
    Location
    Fairbanks, AK.
    Posts
    1,526
    Post Thanks / Like
    Just to make sure I wasn't dreaming I went and looked for the round air cleaner seal...It's a U-shaped hinged plate with edge seal made of felt. Not sure all still have it as one Cub with new engine didn't. Bottom of round filter open but top restricted some. There's more knowledge here than my memories.

    If I wanted to seal it today I'd try some round hollow foam water pipe insulation wrapped around the rear filter and tied on for example.

    Gary

  19. #139
    skywagon8a's Avatar
    Join Date
    Mar 2008
    Location
    SE Mass
    Posts
    9,153
    Post Thanks / Like
    Quote Originally Posted by BC12D-4-85 View Post
    Wes is there a through opening around the air filter element to the rear cowl exit? It would seem that blocking that passage just behind the air filter (or?) might lower the air pressure below the engine. Adding ram air to that area might be raising it is my assumption. Didn't Piper seal that passage?

    Gary
    Gary, Piper did seal that space. I left it off in my Cub just to see what happens and never found a need to put it in as the temperatures all were within my limits. While I can not verify my theory, it appears that maybe the excess ram air which bypasses the round intake filter is actually accelerating the out flowing air thus helping with the cooling. Sort of acting similar to an exhaust augmenter tube?
    N1PA
    Likes Schwarz liked this post

  20. #140
    skywagon8a's Avatar
    Join Date
    Mar 2008
    Location
    SE Mass
    Posts
    9,153
    Post Thanks / Like
    Quote Originally Posted by Schwarz View Post
    It's a bit shy of 2.5-3.0 inches,

    IF after trying other things you find that you still need to increase this opening, try adding a "seaplane" lip to the trailing edge of these side cowl doors. You could just duct tape them on for test purposes. Years ago I participated in some cooling tests of a PA-12 on floats to get an STC for an 0-360 (170 hp). To pass the cooling tests a large lip was placed on the bottom opening as well as lips on the side cowls. It was ugly, but it worked.

    You could also place some aft facing scoops on the lower cowl as Piper did. This will increase your outlet area with the outside aft facing scoops they will cause lower pressure for additional draw. There are many options for the desired results. The bottom line is to get rid of the heated trapped air.
    N1PA
    Thanks Schwarz thanked for this post
    Likes Schwarz, Bowie liked this post

  21. #141
    BC12D-4-85's Avatar
    Join Date
    Feb 2016
    Location
    Fairbanks, AK.
    Posts
    1,526
    Post Thanks / Like
    Quote Originally Posted by skywagon8a View Post
    Gary, Piper did seal that space. I left it off in my Cub just to see what happens and never found a need to put it in as the temperatures all were within my limits. While I can not verify my theory, it appears that maybe the excess ram air which bypasses the round intake filter is actually accelerating the out flowing air thus helping with the cooling. Sort of acting similar to an exhaust augmenter tube?
    It's only a guess for or against sealing part of the filter housing. The manometer might offer some info after a quick seal job tho. Piper did seal it for a reason, perhaps for hot and slow A-model sprayers which mine was at one time. Same for the two lower cowl outlets adjacent to the filter housing (see PDF's below).

    In winter to -50F I blocked my side cowl cheeks and lower cowl outlets with metal plates. Removed the lower cowl fiberglass seaplane lip from Atlee Dodge, and built a cockpit adjustable shutter for the forward original Piper oil cooler (O-320). Worked well so they all do offer added cooling.

    He has two exhaust stacks around which augmenter tubes could be built as another experiment.

    Lower cowl outlets:
    Attached Files Attached Files
    Thanks Schwarz thanked for this post
    Likes Schwarz liked this post

  22. #142
    skywagon8a's Avatar
    Join Date
    Mar 2008
    Location
    SE Mass
    Posts
    9,153
    Post Thanks / Like
    Quote Originally Posted by BC12D-4-85 View Post
    ...He has two exhaust stacks around which augmenter tubes could be built as another experiment.
    Augmenter tubes require a whole different design process. There are specific diameter, length, position of the exhaust exit in relation to the entrance to the augmenter, etc.
    What little I do know about this topic is that it would require some major alterations to everything. It is not just a big pipe around the exhaust. It is a sort of venturi effect.
    N1PA

  23. #143
    BC12D-4-85's Avatar
    Join Date
    Feb 2016
    Location
    Fairbanks, AK.
    Posts
    1,526
    Post Thanks / Like
    See how Piper did the lower cowl and air filter seal here>>>https://www.univair.com/categories/p.../cowling.html?

    Gary

  24. #144

    Join Date
    Oct 2012
    Posts
    4,470
    Post Thanks / Like
    The reported CHTs don't support that there's anything wrong with the cowl. The only thing that's suspect is the oil cooler configuration. Don't overthink it. Fix the cooler configuration.
    Thanks Schwarz thanked for this post
    Likes DENNY, Schwarz liked this post

  25. #145
    CamTom12's Avatar
    Join Date
    Jul 2015
    Location
    Huntsville, AL
    Posts
    635
    Post Thanks / Like

    Oil temperature question

    I dunno, I think the problem is deeper than just the 3Ē SCAT to the oil cooler. I think weíre dealing with a couple of things (all airflow related, though).

    I think Schwartz needs to increase his SCAT size to the oil cooler to 4Ē as soon as he has the opportunity. Thatíll really open up his oil cooling potential.

    I also think that on a cub (Iím assuming has magnetos), cruise CHTs in the 370-380 range are high. High CHTs and high oil temps (plus the picture of the lower cowl exit hole) lead me to think heís go differential pressure issues in his cowling. Plus the 2Ē pressure differential that he measured is very low.

    But Iím no expert, just my opinion. I moved my airplane (that experienced no temperature issues up north) from AK to the Deep South. Temps are a whole nother animal down here.
    Thanks Schwarz thanked for this post
    Likes Schwarz liked this post

  26. #146
    Schwarz's Avatar
    Join Date
    Oct 2016
    Location
    Abilene, Texas
    Posts
    40
    Post Thanks / Like
    Well making progress, changed the 3" SCAT to 4" SCAT and flew this afternoon, OAT is still 100*f, flew at 2350-2400 about 2500' 800' AGL for 30 minutes. Oil temp stabilized at 220* and didn't increase past that, before it kept going at or above 235* before I got back on the ground. I haven't done anything but put on the larger SCAT, still plan to improve the airflow through the cowling with a lip and address the vernatherm seat, after the weather cools down some.

    4"


    3"


    Back side of my air filter housing is open, don't know if that is hindering airflow or not,






    Thank you everyone for the tips, its a work in progress to get the oil temps down and tweak the cooling on the engine, its too hot to stay in the hangar long

    Wes Schwarz
    Likes CamTom12 liked this post

  27. #147
    CamTom12's Avatar
    Join Date
    Jul 2015
    Location
    Huntsville, AL
    Posts
    635
    Post Thanks / Like
    is there room around that SCAT to your carb heat to close up the back side of the air filter "tunnel?"

  28. #148
    BC12D-4-85's Avatar
    Join Date
    Feb 2016
    Location
    Fairbanks, AK.
    Posts
    1,526
    Post Thanks / Like
    Above I mentioned seeing factory seals around the air filters on standard Cubs. I've since looked at three 180 Cubs (not Crosswinds STC) and they were also sealed. That's only a for what's it worth comment as I don't know if there's any benefit leaving it open or closed. I can see where any pressure filling or flow disturbance out the cowl caused by an opening might increase local lower cowl pressure. If it were mine I'd temporarily wrap the rear of the filter element to make a seal then go fly and learn something.

    Gary
    Likes Tim liked this post

  29. #149
    Steve Pierce's Avatar
    Join Date
    Mar 2002
    Location
    Graham, TX
    Posts
    18,533
    Post Thanks / Like
    I run the hoses through the heater box. Make a lip out of posterboard and then you can transfer that pattern to aluminum. Here is a link showing how I have done it. https://www.shortwingpipers.org/foru...he-Bottom-Cowl
    Duct tape it and see how much of a change you get.
    Steve Pierce

    Everybody is ignorant, only on different subjects.
    Will Rogers

  30. #150
    Schwarz's Avatar
    Join Date
    Oct 2016
    Location
    Abilene, Texas
    Posts
    40
    Post Thanks / Like
    I'm going to do some more testing with the manometer to see how much I can improve the airflow, I think I'm going to wait a couple of weeks and see if the weather changes. I worked late Wednesday evening and early Thursday to try and miss some of the heat. I still carry my roll of duct tape, I will tape it off and do a before and after reading on the manometer. I flew it today, 102 *f and oil temps remained 215-220, much improved.

    Thanks.
    Wes Schwarz

  31. #151
    Steve Pierce's Avatar
    Join Date
    Mar 2002
    Location
    Graham, TX
    Posts
    18,533
    Post Thanks / Like
    Those temps over ambient wouldn't bother me.
    Steve Pierce

    Everybody is ignorant, only on different subjects.
    Will Rogers
    Thanks Schwarz thanked for this post
    Likes CamTom12, Schwarz liked this post

  32. #152
    CamTom12's Avatar
    Join Date
    Jul 2015
    Location
    Huntsville, AL
    Posts
    635
    Post Thanks / Like

    Oil temperature question

    Quote Originally Posted by Steve Pierce View Post
    Those temps over ambient wouldn't bother me.
    Thatís about 115į over ambient, not bad.

    Howís your CHTs? If theyíre still up Iíd still work on the lower cowl. Actually, I have a problem with improvements on systems that are probably good enough - I might still be working on it
    Likes Schwarz liked this post

  33. #153
    Schwarz's Avatar
    Join Date
    Oct 2016
    Location
    Abilene, Texas
    Posts
    40
    Post Thanks / Like
    Ya my CHTs are still 370-380, doesnít seem to matter what OAT. Iím still going to try to improve on what I have but at least I can fly it when itís hot outside!


    Sent from my iPhone using SuperCub.Org
    Wes Schwarz

  34. #154
    skywagon8a's Avatar
    Join Date
    Mar 2008
    Location
    SE Mass
    Posts
    9,153
    Post Thanks / Like
    Quote Originally Posted by Schwarz View Post
    Ya my CHTs are still 370-380, doesn’t seem to matter what OAT. I’m still going to try to improve on what I have but at least I can fly it when it’s hot outside!
    There is nothing wrong with 370-380.
    N1PA
    Thanks stewartb thanked for this post
    Likes CamTom12, Schwarz liked this post

  35. #155

    Join Date
    Oct 2012
    Posts
    4,470
    Post Thanks / Like
    It's kind of the ideal target!
    Likes Schwarz liked this post

  36. #156
    CamTom12's Avatar
    Join Date
    Jul 2015
    Location
    Huntsville, AL
    Posts
    635
    Post Thanks / Like
    What they said. So long as you can keep them under 400 in a climb Iíd be happy with that.
    Likes Schwarz liked this post

Similar Threads

  1. Oil temperature
    By King Brown in forum Cafe Supercub
    Replies: 1
    Last Post: 06-30-2016, 10:15 AM
  2. $25 Outside Air Temperature
    By Darrel Starr in forum Cafe Supercub
    Replies: 7
    Last Post: 06-01-2015, 11:35 AM
  3. Oil temperature, PA-11
    By gdkl in forum Cafe Supercub
    Replies: 16
    Last Post: 07-01-2012, 04:11 PM
  4. Oil Temperature
    By Bernard in forum Experimental Cubs
    Replies: 5
    Last Post: 05-31-2010, 05:04 PM

Bookmarks

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •