Page 2 of 3 FirstFirst 123 LastLast
Results 41 to 80 of 104

Thread: IO-520 Compressions

  1. #41
    little wing's Avatar
    Join Date
    Dec 2013
    Posts
    336
    Post Thanks / Like
    Since operation has been introduced into this thread....

    When I got my 185 (550D equipped) I heard many things on operation and leaning and LOP operation. I began my own research because I was getting confused with all the different recommendations from friends and acquaintances and came across these webinars presented by the Continental's Director of Customer Service.
    Part 1. https://www.youtube.com/watch?v=4hmG5qwCpbw
    Part 2. https://www.youtube.com/watch?v=3MPGP_GzXlI

    Continental seems to reference GAMI's research as definitive and above their own in many regards, so I took the Advanced Pilot Seminar (GAMI's engine operation and leaning course, online version). There is a free sample available here. https://www.advancedpilot.com/onlinecourse.html In their demystification they explain the wives tales, rumors, and how so many people, including A/Ps and I/As, have misinterpreted the data over the years. The full online course is $400, steep but the additional education was worth it to me, maybe others will also.
    Likes OLDCROWE, stewartb, Steve Pierce, sub3 liked this post

  2. #42

    Join Date
    Oct 2012
    Posts
    2,436
    Post Thanks / Like
    Those youtube videos are by Bill Ross, who now is with Superior Air Parts. Don't forget you can get his book download for free.

    http://www.superiorairparts.com

    I'm looking forward to exploring LOP with my API injection. The exp alternative to GAMIs!
    Likes Delta Cub liked this post

  3. #43

    Join Date
    Dec 2006
    Location
    Meanwhile,...
    Posts
    4,328
    Post Thanks / Like
    My engine via the previous owner had significant cylinder issues (two sets in 600 hours with oil consumption, valve issues and cylinder cracking problems) which I knew going in. I put up with it for awhile without any problem other than oil consumption growing to 1qt/6 and then put all new on and I still had a few valve problems running it easy per the previous owners notes both LOP and ROP so I did what is happening here I asked lots of questions...hence my operational change. I would like to study it more and when I hang a fresh engine (now scheduled in 2-2.5 years unless the oil dribble somewhere on the rear of the case wins) I will likely explore LOP operations at that time but right now I wouldn't change at gun point from what I'm seeing in a fairly high time engine (that earns a living) that is on track to keep it up well through TBO.
    Last edited by OLDCROWE; 11-13-2017 at 02:38 PM. Reason: still can't spell
    "Don't feed the hipsters"
    Likes sub3 liked this post

  4. #44
    hotrod180's Avatar
    Join Date
    May 2008
    Location
    Port Townsend, WA
    Posts
    1,438
    Post Thanks / Like
    Quote Originally Posted by stewartb View Post
    The two most disagreed upon topics in aviation with big Continentals? Low compressions and LOP operations...... MMO's probably the third most disagreed on thing in aviation.
    Don't forget mogas.
    Cessna Skywagon-- accept no substitute!
    Likes KevinJ liked this post

  5. #45
    aktango58's Avatar
    Join Date
    Aug 2004
    Location
    18AA
    Posts
    8,093
    Post Thanks / Like
    I realize that many folks have great results running LOP, and we all have had good and bad with engines, that being said I have never had an instructor, pilot, owner or Chief pilot on any commercial plane tell me to run LOP.

    Operations that changed 15 engines a year (TBO requirement for 135) ran them rich!

    Why? Fuel is cooling, as said above 75% it is a big deal- why you should always run FULL THROTTLE on take off- there is an extra jet that opens and sends cooling fuel into the cylinders further adding to cooling.

    How critical is this? We had a fuel controller set 1 to 1.5 gallons leaner than what was called for in the manual. We went through 2 cylinders in 500 hours, and almost lost a third. Adjusted the controller up and the engine is run flawlessly. Fuel costs at over $5/gallon is still far less than cylinder changes.

    Having enough fuel on take-off to keep the cylinders cool is very important, as is cooling in flight. LOP might be just fine, but be sure to keep eyes on all temps. to ensure you are not melting the 3&4 jugs.
    I don't know where you've been me lad, but I see you won first Prize!
    Likes DENNY, skywagon8a, OLDCROWE, Nark liked this post

  6. #46
    www.SkupTech.com mike mcs repair's Avatar
    Join Date
    Aug 2004
    Location
    chugiak AK
    Posts
    8,484
    Post Thanks / Like
    Quote Originally Posted by aktango58 View Post
    I realize that many folks have great results running LOP, and we all have had good and bad with engines, that being said I have never had an instructor, pilot, owner or Chief pilot on any commercial plane tell me to run LOP.Operations that changed 15 engines a year (TBO requirement for 135) ran them rich!Why? Fuel is cooling, as said above 75% it is a big deal- why you should always run FULL THROTTLE on take off- there is an extra jet that opens and sends cooling fuel into the cylinders further adding to cooling.How critical is this? We had a fuel controller set 1 to 1.5 gallons leaner than what was called for in the manual. We went through 2 cylinders in 500 hours, and almost lost a third. Adjusted the controller up and the engine is run flawlessly. Fuel costs at over $5/gallon is still far less than cylinder changes.Having enough fuel on take-off to keep the cylinders cool is very important, as is cooling in flight. LOP might be just fine, but be sure to keep eyes on all temps. to ensure you are not melting the 3&4 jugs.
    we set our high pressure to be needle strait down, beyond redline for the reasons you mention on takeoff on 185

  7. #47

    Join Date
    Aug 2002
    Location
    Talkeetna Alaska
    Posts
    187
    Post Thanks / Like
    An old-timer once told me that fuel is the cheapest coolant you can buy.

    RK
    Likes mike mcs repair liked this post

  8. #48

    Join Date
    Jul 2010
    Location
    Elizabeth, WV
    Posts
    403
    Post Thanks / Like
    Quote Originally Posted by Eddie Foy View Post

    Does anyone do a direct compression test?
    Yes. There was an old guy that worked as a roving mechanic in Ohio. He had a set of gauges that screwed, one into each top plug hole. He would rotate the prop two revolutions or maybe it was three. Then he would read the numbers off the gauges. Pretty slick-no air compressor needed-no electric needed. Just like doing a compression check on a car engine while rotating it with the starter. Nobody I knew ever double checked his numbers with a leakdown gauge but his numbers were mostly in the low sixties to high seventies and appeared normal for the engines. I saw one set of those gauges get sold on ebay and I was disappointed that they sold before I saw them. I have no idea who manufactured them but I would still like a set if I could afford them. Of course I also have a Seyboth fabric tester for the guys who want to see the low green or high green looks like.

  9. #49
    Tom3holer's Avatar
    Join Date
    May 2012
    Location
    Cape Cod
    Posts
    387
    Post Thanks / Like
    This is a great discussion that I am enjoying very much and learning a lot.
    I have read almost everything I can find on LOP and ran it as far back as the mid 90's in my IO-470 powered Debonair long gone to Dr. Zarum who lives nearby and takes very good care of her. The J3 I had in the intervening years did not want any part of LOP so I ran FM or fixed mixture all the time. I did keep abreast of LOP operations and the updates on the learning curve. It is nothing new as they ran that way back in the Super Connie days with the 4360's or whatever they were and it indeed extended their longevity. There are many benefits to LOP operation other than fuel consumption. Head temps are cooler than at ROP for one thing. Just because an operator has had success running one way does not mean a new method may not be better. If I were a commercial operator and had what I considered success running one way I would be reluctant to change too until the day came when my competitor with the same equipment was operating differently and being just as reliable at a considerable cost savings. It is more involved and requires a learning curve I agree and is not for everyone.

    I ordered the 5" and up diff pressure gauge today and we will try it again in a couple of days when it comes in.
    As luck would have it the borescope broke the other day so it will be a couple of days before my mech can get a good look at the jugs.
    On the oil out the breather thing I have a theory that it might be due the angle of the sweepback of the breather as it exits beneath the firewall. ON mine it extends back parallel to the bottom of the fuselage. As a test I put about a 2 1/2 extension of vynl tubing on it to see if perhaps there was a venturi effect going on and if extending it further back might increase the effect. I went through about a quart of oil in a little over an hour and a half. Tomorrow we are changing the tube to exit an inch or so below the firewall and cut it parallel to the ground in level flight and see if that helps. That was the recommendation by several members here and a good friend in Greenville with a 0-520 powered 180.
    Tom

  10. #50

    Join Date
    Sep 2002
    Posts
    200
    Post Thanks / Like
    “good friend in Greenville with a 0-520 powered 180.”

    are his initials CM?

  11. #51
    Tom3holer's Avatar
    Join Date
    May 2012
    Location
    Cape Cod
    Posts
    387
    Post Thanks / Like
    Nope, WA, has a beautiful private strip nearby in Rockwood.
    Thanks mam90 thanked for this post

  12. #52

    Join Date
    Mar 2006
    Posts
    9
    Post Thanks / Like
    Quote Originally Posted by N86250 View Post
    Yes. There was an old guy that worked as a roving mechanic in Ohio. He had a set of gauges that screwed, one into each top plug hole. He would rotate the prop two revolutions or maybe it was three. Then he would read the numbers off the gauges. Pretty slick-no air compressor needed-no electric needed. Just like doing a compression check on a car engine while rotating it with the starter. Nobody I knew ever double checked his numbers with a leakdown gauge but his numbers were mostly in the low sixties to high seventies and appeared normal for the engines. I saw one set of those gauges get sold on ebay and I was disappointed that they sold before I saw them. I have no idea who manufactured them but I would still like a set if I could afford them. Of course I also have a Seyboth fabric tester for the guys who want to see the low green or high green looks like.
    He used to annual my cub, I thought those screw in gauges were pretty neat. I miss those days.

  13. #53
    cubdriver2's Avatar
    Join Date
    Apr 2003
    Location
    upstate NY
    Posts
    7,943
    Post Thanks / Like
    Quote Originally Posted by Tom3holer View Post
    Nope, WA, has a beautiful private strip nearby in Rockwood.
    Bill's a great guy

    Glenn
    "Optimism is going after Moby Dick in a rowboat and taking the tartar sauce with you!"

  14. #54
    behindpropellers's Avatar
    Join Date
    Feb 2003
    Location
    NE Ohio
    Posts
    6,552
    Post Thanks / Like

  15. #55
    Tom3holer's Avatar
    Join Date
    May 2012
    Location
    Cape Cod
    Posts
    387
    Post Thanks / Like
    Cubdriver2, Yes he is and his wife Maria cooks at Maynards and makes the best mushroom linguini I've ever had.

    The new gauge should be here tomorrow and if things go well should be able to fly it and retest the compression.

  16. #56

    Join Date
    Dec 2006
    Location
    Meanwhile,...
    Posts
    4,328
    Post Thanks / Like
    Quote Originally Posted by behindpropellers View Post
    Tried to go there but I couldn’t see the keyboard with a bag over my head.
    "Don't feed the hipsters"

  17. #57

    Join Date
    Jul 2010
    Location
    Elizabeth, WV
    Posts
    403
    Post Thanks / Like
    Quote Originally Posted by Rudy View Post
    He used to annual my cub, I thought those screw in gauges were pretty neat. I miss those days.
    His name is in many, many logbooks. Everybody liked his work. Never heard a single bitch.

  18. #58
    aktango58's Avatar
    Join Date
    Aug 2004
    Location
    18AA
    Posts
    8,093
    Post Thanks / Like
    Quote Originally Posted by Tom3holer View Post
    This is a great discussion that I am enjoying very much and learning a lot.
    I have read almost everything I can find on LOP and ran it as far back as the mid 90's in my IO-470 powered Debonair long gone to Dr. Zarum who lives nearby and takes very good care of her. The J3 I had in the intervening years did not want any part of LOP so I ran FM or fixed mixture all the time. I did keep abreast of LOP operations and the updates on the learning curve. It is nothing new as they ran that way back in the Super Connie days with the 4360's or whatever they were and it indeed extended their longevity. There are many benefits to LOP operation other than fuel consumption. Head temps are cooler than at ROP for one thing. Just because an operator has had success running one way does not mean a new method may not be better. If I were a commercial operator and had what I considered success running one way I would be reluctant to change too until the day came when my competitor with the same equipment was operating differently and being just as reliable at a considerable cost savings. It is more involved and requires a learning curve I agree and is not for everyone.

    Tom
    While I have no reason to refute your research and historical knowledge, your assertion on LOP being great to operate would carry more influence if it was not preceded by the question: Why is my engine having problems?

    Again, if all cylinders were 10 lbs lower than before I would be more apt to think gauge, the one is only 2 lbs lower indicating something else is amiss.
    Last edited by aktango58; 11-15-2017 at 03:21 PM.
    I don't know where you've been me lad, but I see you won first Prize!
    Likes mike mcs repair, skywagon8a liked this post

  19. #59
    Steve Pierce's Avatar
    Join Date
    Mar 2002
    Location
    Graham, TX
    Posts
    16,456
    Post Thanks / Like
    Ok, I just did a differential compression check on a Lycoming O-320 150 hp which has a bore of 5.125". I normally bring it up on compression to where I hear the impulse coupling snap and stop, install gauges and adjust air pressure. Using the E-2M1000 with the .060" orifice I got 78/80 without having to mess with the prop. Immediately installed the E-2A with .040" orifice and it showed 64/80 at the same prop position. Moved the prop around and best I got was 74/80. Went to the other three cylinders and they were all 78-79/80 with little prop movement using the bigger bore gauges and they were all 4-6 psi lower with a lot of prop back and forth with the .040" gauges. Both gauges are fresh out of calibration from Eastern Technology.


    Sent from my SM-N900V using SuperCub.Org mobile app
    Steve Pierce

    Everybody is ignorant, only on different subjects.
    Will Rogers
    Thanks DENNY, N86250, cubscout, cubpilot2 thanked for this post
    Likes DENNY, mike mcs repair liked this post

  20. #60
    aktango58's Avatar
    Join Date
    Aug 2004
    Location
    18AA
    Posts
    8,093
    Post Thanks / Like
    Thank you for going to the extra work to determine this Steve! Great Information.
    I don't know where you've been me lad, but I see you won first Prize!

  21. #61
    behindpropellers's Avatar
    Join Date
    Feb 2003
    Location
    NE Ohio
    Posts
    6,552
    Post Thanks / Like
    Very interesting. Thanks, Steve.

    Guess I will go out to the hanger and see which orifice I have.

  22. #62
    Steve Pierce's Avatar
    Join Date
    Mar 2002
    Location
    Graham, TX
    Posts
    16,456
    Post Thanks / Like
    I also have a call into Continental to verify the proper gauge in their opinion.
    Steve Pierce

    Everybody is ignorant, only on different subjects.
    Will Rogers

  23. #63
    Eddie Foy's Avatar
    Join Date
    Dec 2014
    Location
    South Florida
    Posts
    2,259
    Post Thanks / Like
    Steve,
    Your results are what I would expect.
    Eddie Foy
    "Put out my hand and touched the face of God"

  24. #64
    www.SkupTech.com mike mcs repair's Avatar
    Join Date
    Aug 2004
    Location
    chugiak AK
    Posts
    8,484
    Post Thanks / Like
    this is the newer version of the one I have(mines like 30 years old almost), http://www.ustool.com/tp104-miscella...4040-l-en.html

    any idea what size it is internally? might have to go take it apart

  25. #65

    Join Date
    May 2017
    Posts
    98
    Post Thanks / Like
    Interesting discussion. It used to be that the larger orface gage was used on engines over 1000 cu in. I guess the Continental SI says to use it for bores over 5”. I wonder what caused FAA to change AC43.13-1b?

    I used LOP on the A36 with a 550 that I used to fly for work. The biggest issue I found was lag in the EGT gage. It had a JPI, and after a lot of trial and error, I found that when leaning, if you tried to lean to 25 degrees LOP, within a couple minutes you would be 75 - 100 degrees LOP and on the edge of detonation. When leaning I found that if you slowly leaned to the first indication of peak and stopped right there, in a minute or so it would be 25 degrees LOP and cylinder head temps woul cool right down, and it would run smooth as silk. Fuel flow would be in the 14.5- 15 got instead of the 17 gph rich of peak. Airspeed would be about 2 mph less.


    Sent from my iPhone using Tapatalk
    Likes 180Marty liked this post

  26. #66
    Eddie Foy's Avatar
    Join Date
    Dec 2014
    Location
    South Florida
    Posts
    2,259
    Post Thanks / Like
    Oddly enough, SB03-3 makes no mention of orifice size. It references the E2M and the E2A with the .040 orifice. It makes no mention of the E2M-1000 with the .060 orifice.
    Remember there are two orifices per gauge set. An internal one and a master to establish the min for a Continental. The E2-M has the Master built in.

    Quote Originally Posted by dgapilot View Post
    Interesting discussion. It used to be that the larger orface gage was used on engines over 1000 cu in. I guess the Continental SI says to use it for bores over 5”. I wonder what caused FAA to change AC43.13-1b
    Eddie Foy
    "Put out my hand and touched the face of God"
    Likes dgapilot liked this post

  27. #67
    Eddie Foy's Avatar
    Join Date
    Dec 2014
    Location
    South Florida
    Posts
    2,259
    Post Thanks / Like
    Quote Originally Posted by Steve Pierce View Post
    I also have a call into Continental to verify the proper gauge in their opinion.
    As I understand it, the FAA pub rules unless it is overriden by the Manufacturer. Since I am unaware of any guidance by TCM or Lycoming as to orifice size, it appears AC43 is your bible.
    Eddie Foy
    "Put out my hand and touched the face of God"

  28. #68
    Steve Pierce's Avatar
    Join Date
    Mar 2002
    Location
    Graham, TX
    Posts
    16,456
    Post Thanks / Like
    It is interesting because I was unaware of this until recently. The 43.13 use to list above 1000 cubic inches which the radials I use to work on fell in that category. I guess displacement doesn't matter but bore size does. Be interesting to see what Continental says.

    Sent from my SM-N900V using SuperCub.Org mobile app
    Steve Pierce

    Everybody is ignorant, only on different subjects.
    Will Rogers

  29. #69
    Tom3holer's Avatar
    Join Date
    May 2012
    Location
    Cape Cod
    Posts
    387
    Post Thanks / Like
    TCM does offer guidance in their SB03-3 in that they depict a E2A gauge which is a .040 orifice.

  30. #70
    Eddie Foy's Avatar
    Join Date
    Dec 2014
    Location
    South Florida
    Posts
    2,259
    Post Thanks / Like
    It would seem that TCM needs to clarify SB03-3 as to bore size.



    Quote Originally Posted by Steve Pierce View Post
    It is interesting because I was unaware of this until recently. The 43.13 use to list above 1000 cubic inches which the radials I use to work on fell in that category. I guess displacement doesn't matter but bore size does. Be interesting to see what Continental says.

    Sent from my SM-N900V using SuperCub.Org mobile app
    Eddie Foy
    "Put out my hand and touched the face of God"

  31. #71
    Eddie Foy's Avatar
    Join Date
    Dec 2014
    Location
    South Florida
    Posts
    2,259
    Post Thanks / Like
    Yet, they make no mention of using the larger orifice gauge on bores of 5 inches or greater.

    Quote Originally Posted by Tom3holer View Post
    TCM does offer guidance in their SB03-3 in that they depict a E2A gauge which is a .040 orifice.
    Last edited by Eddie Foy; 11-16-2017 at 07:12 AM.
    Eddie Foy
    "Put out my hand and touched the face of God"

  32. #72
    Steve Pierce's Avatar
    Join Date
    Mar 2002
    Location
    Graham, TX
    Posts
    16,456
    Post Thanks / Like
    Got this from my friend at Continental this morning:

    Below is a snip from the M-0 Standard Practices Manual. SB03-3 has been incorporated into this manual.






    Ron Humphrey
    Manager Product Support
    Continental Motors
    888.826.5465

    Steve Pierce

    Everybody is ignorant, only on different subjects.
    Will Rogers

  33. #73
    Steve Pierce's Avatar
    Join Date
    Mar 2002
    Location
    Graham, TX
    Posts
    16,456
    Post Thanks / Like
    For whatever reason the FAA changed the standards in the AC 43.13. Eastern Technology seems to have picked up on that and Continental did not. I would be curious if Continental did any testing comparing the two.
    Steve Pierce

    Everybody is ignorant, only on different subjects.
    Will Rogers

  34. #74

    Join Date
    May 2017
    Posts
    98
    Post Thanks / Like
    Or is it all a marketing ploy to make us think the cylinders are better than they really are? All that said, I've never seen an engine fail from low compression! Cam and lifter condition contributes to power output more than one or more cylinders with "low" compression. I've seen lots of engines that won't make static power, yet all the cylinders are in the 70s for compression.

  35. #75
    Steve Pierce's Avatar
    Join Date
    Mar 2002
    Location
    Graham, TX
    Posts
    16,456
    Post Thanks / Like
    I read some TCM data once where they ran a big bore Continental without any piston rings and it made rated power. It was in reference to mechanics pulling cylinders prematurely.
    Steve Pierce

    Everybody is ignorant, only on different subjects.
    Will Rogers

  36. #76
    Eddie Foy's Avatar
    Join Date
    Dec 2014
    Location
    South Florida
    Posts
    2,259
    Post Thanks / Like
    Can’t see the attachment.

    Quote Originally Posted by Steve Pierce View Post
    Got this from my friend at Continental this morning:

    Below is a snip from the M-0 Standard Practices Manual. SB03-3 has been incorporated into this manual.






    Ron Humphrey
    Manager Product Support
    Continental Motors
    888.826.5465

    Eddie Foy
    "Put out my hand and touched the face of God"

  37. #77
    Steve Pierce's Avatar
    Join Date
    Mar 2002
    Location
    Graham, TX
    Posts
    16,456
    Post Thanks / Like
    Quote Originally Posted by Eddie Foy View Post
    Can’t see the attachment.
    Compression tests.png
    Steve Pierce

    Everybody is ignorant, only on different subjects.
    Will Rogers

  38. #78
    Steve Pierce's Avatar
    Join Date
    Mar 2002
    Location
    Graham, TX
    Posts
    16,456
    Post Thanks / Like
    Tom, What did you find when you borescoped the cylinders? Oil analysis? Oil filter/screen inspection?
    Steve Pierce

    Everybody is ignorant, only on different subjects.
    Will Rogers

  39. #79
    hotrod180's Avatar
    Join Date
    May 2008
    Location
    Port Townsend, WA
    Posts
    1,438
    Post Thanks / Like
    Curious about this orifice business, I googled compression testers.
    Here's one from Spruce:

    http://www.aircraftspruce.com/catalo...saAqwaEALw_wcB

    and here's a clip from the description of that tester:
    "
    NOTE: The ATS 2EM Differential Pressure Tester has a .040” orifice as required by Teledyne Continental SB03-3 Service Bulletin, and is the proper type of instrument to test ALL Teledyne Continental engines in accordance with the aforementioned bulletin. The ATS 2EM also complies Textron Lycoming SI-1191A Service Instruction and is appropriate for ALL Textron Lycoming engines as indicated in the Service Instruction.
    "

    Here's another tester:

    http://www.aircraftspruce.com/catalo...QaAiqkEALw_wcB

    and a clip from the description for that one:
    "
    Model E2A Tester, for cylinders of less than a 5.00 inch bore* with a .040 inch diameter orifice, that eliminates all guess-work by enabling you to determine the exact location and cause of your engine's efficiency loss. This tester is recommended by TCM per
    Service Bulletin SB03-3"

    and here's a link to SB03-3:

    http://www.aircraftspruce.com/catalo...cebulletin.pdf

    As pointed out, SB03-3 doesn't specify a particular orifice size, but it does call out two different model testers- both of which have a .040 orifice.
    Cessna Skywagon-- accept no substitute!
    Likes mike mcs repair liked this post

  40. #80
    Steve Pierce's Avatar
    Join Date
    Mar 2002
    Location
    Graham, TX
    Posts
    16,456
    Post Thanks / Like
    https://www.lycoming.com/content/ser...ction-no-1191a

    The orifice size of the differential compression measuring device is critical if consistent andmeaningful cylinder analysis are to be obtained; the larger the orifice the less chance of detectingpotential problems. Therefore, a specific orifice size that provides an acceptable leak rate hasbeen selected for all Textron Lycoming engines; the instructions described herein are based onthis orifice which is .040 in. dia. (No. 60 drill) x .250 in long, with entrance angle of 59/60 °.
    Steve Pierce

    Everybody is ignorant, only on different subjects.
    Will Rogers

Similar Threads

  1. Compressions vs. Performance
    By cubdrvr in forum Cafe Supercub
    Replies: 10
    Last Post: 12-15-2003, 05:51 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
  •