---------------------------------------------------------- Yak-List Digest Archive --- Total Messages Posted Mon 06/03/13: 16 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:23 AM - Engine Start Mystery (Sam Sax) 2. 05:57 AM - Re: Re: compressor problems (A. Dennis Savarese) 3. 06:17 AM - Re: compressor problems (gord) 4. 06:27 AM - Say It Ain't So... (Rico Jaeger) 5. 06:57 AM - Re: Re: Compressor problem (doug sapp) 6. 07:09 AM - Re: compressor problems (doug sapp) 7. 07:39 AM - Re: compressor problems (Bitterlich, Mark G CIV NAVAIR, WD) 8. 09:26 AM - Re: Engine Start Mystery (bill wade) 9. 05:53 PM - Re: Engine Start Mystery (cjpilot710@aol.com) 10. 07:01 PM - Re: Engine start mystery (Frank Stelwagon) 11. 07:53 PM - Re: Engine Start Mystery (Roger Kemp M.D.) 12. 07:53 PM - Re: Say It Ain't So... (Roger Kemp M.D.) 13. 08:02 PM - Engine Start Mystery (Sam Sax) 14. 08:10 PM - Re: Engine start mystery (Sam Sax) 15. 08:21 PM - Re: Engine Start Mystery (Sam Sax) 16. 09:28 PM - Re: Engine Start Mystery (Roger Kemp M.D.) ________________________________ Message 1 _____________________________________ Time: 05:23:21 AM PST US From: "Sam Sax" Subject: Yak-List: Engine Start Mystery This is a "good" one... I fly my CJ6 with the M-14p engine over a decade and have never seen or heard of this happening. I'd appreciate any ideas shedding light on this mystery... Earlier today upon returning from a routine acro practice flight, taxied to the fuel pump and performed a normal shutdown. After fueling and as a practice before each start, I have my GIB rotate the prop by hand a few blades as I prime (a little when engine is hot). My GIB reported that the first two blades were tight with normal feel of compression but the next blade was very soft. I didnt think much of it and asked him to hop in and I commenced with normal engine start procedure. Upon pressing the Air-Start button, the blades rotated in an amazingly fast rate - much faster than normal start rotation speed - as if there was no compression in the cylinders... Moreover, there was no ignition whatsoever during this fast rotation. I released the start button, waited a minute and tried again - same high speed rotation and no ignition... At this time I got very worried and thought that the rear segment of the crankshaft somehow sheared off (on shutdown??)! Spent about 10 minutes with my knowledgeable GIB trying to figure out what could have happened. At that point, I asked him to try rotating the prop by hand and see if ANY of the cylinders have compression. As he was turning the prop by hand, I could see his strain as he rotates blade by blade - he proceeded to report feeling normal compression resistance on all blades. At this point I wanted to attempt another start. GIB was back in the rear cockpit and I pressed the starter button - engine started on the second blade (as it normally does)! I have the JP Instrument 9 Cylinder unit where I can see CHT and EGT for all 9 cylinders - All showing normal! Taxied back to hangar - Performed a Magneto check - Normal. Oil, Fuel pressures and temps - normal. I shut down again and re-started two additional times in an effort to duplicate the problem... Started perfectly normal each time. So... what the hell happened there? I am thinking a stuck intake valve but one stuck valve will not make the prop spin that fast on starting... Two stuck valves? Three?? Can that happen? If one did stick, why wasn't there any ignition on the other cylinders? If the sticking valve was the intake valve on #7 cylinder (that gets most of the Priming flow), I can see no ignition condition but this is only a guess. Some engine info: M14-P standard (360HP) Total time: 765 hours since new Last compression check (4 months ago): 77 - 78 all cylinders Engine oil: Philips 25W60 multi viscosity oil Last Valve Lash adjustment: 80 hours ago System Air Pressure at first re-start attempt: 42 ATM, at last (Fifth start) 28 ATM Location, Hot Miami, FL Anyone seen anything like this before? Ideas? Thank you in advance for any input, Sam Sax Miami FL ________________________________ Message 2 _____________________________________ Time: 05:57:25 AM PST US From: "A. Dennis Savarese" Subject: Re: Yak-List: Re: compressor problems Also on the banjo fitting on top of the fine fuel filter as well. Although this banjo fitting VERY rarely ever leaks unless someone has recently replaced the hoses. A. Dennis Savarese 334-285-6263 334-546-8182 (mobile) www.yak-52.com Skype - Yakguy1 On 6/2/2013 12:01 PM, Roger Kemp M.D. wrote: > Absolutely! Happens on the banjo fittings on the fuel pump also! > Doc > > Sent from my iPad > > On Jun 2, 2013, at 11:42 AM, bill wade > wrote: > >> I just ordered some Alu washer's from summit. The lower part of the >> shaft that goes through the Banjo alows the 10mm washer to move >> around quite a bit, the disigners should have put a sholder on the >> nut to hold the waser in place. >> *Seller: **summitracing_sales* >> *( >> **501612* >> *) >> * >> ** >> *Item title * >> *Price* >> >> *Shipping price* >> >> *Qty* >> *Item total* >> >> Fragola 999218 Crush Washers 18mm Aluminum Set of 10 >> >> ( item: 111074136794 >> >> transaction: 1033399548001 >> >> ) >> >> >> >> >> Paid on May-29-13 >> $5.95 >> Free >> 1 >> $5.95 >> Expedited Shipping >> Estimated delivery: Mon. Jun. 3 >> >> >> Fragola 999214 Crush Washers 14mm Aluminum Set of 10 >> >> ( item: 330919352626 >> >> transaction: 830513793014 >> >> ) >> >> >> >> >> Paid on May-29-13 >> $4.95 >> $4.95 >> 1 >> $4.95 >> Expedited Shipping >> Estimated delivery: Mon. Jun. 3 >> >> >> Fragola 999210 Crush Washers 10mm Aluminum Set of 10 >> >> ( item: 330924872307 >> >> transaction: 830513794014 >> >> ) >> >> >> >> >> Paid on May-29-13 >> $3.95 >> -- >> 2 >> $7.90 >> Shipped with item above >> Estimated delivery: Mon. Jun. 3 >> >> >> >> >> Subtotal $18.80 >> >> Shipping and handling $4.95 >> >> >> >> >> >> Shipping Discount from seller summitracing_sales $14.85 >> >> >> >> >> >> Total $23.75 >> >> >> *From:* Gary Gabbard > >> *To:* "yak-list@matronics.com " >> > >> *Sent:* Sunday, June 2, 2013 10:26 AM >> *Subject:* Re: Yak-List: Re: compressor problems >> >> > >> >> Try Harbor Freight. They have plastic assortment boxes of copper >> crush washers. Gary. CJ. N22YK >> >> Sent from my iPhone >> >> On Jun 2, 2013, at 7:14, "Roger Kemp M.D." > > wrote: >> >> > >> > >> > Mozam, >> > Thanks! I have been looking all over the place for a reasonable >> crush washer source. Did not even think about McMaster Carr! >> > Gord, he is right about the compressor check valve at the >> compressor. It needs to cleaned after about a hundred hours at the most. >> > I need to clone me so one can be my crew chief and I can FLY! Ah, >> the joys of owning a military aircraft! >> > Doc >> > >> > Sent from my iPad >> > >> > On Jun 2, 2013, at 8:56 AM, "Mozam" > > wrote: >> > >> > >> >> >> >> Ive seen this before on my plane several times. Your compressor >> may be just fine. Try tightening and re-safety wiring the banjo >> fitting that attaches the air line to the compressor. When the >> compressor reaches 3.0 ATM the fitting starts to leak the air out and >> it cannot build the pressure any higher. >> >> >> >> Id replace the crush washers while youre at it just to make sure >> you fix the leak. >> >> >> >> Also, this would be a good time to remove, disassemble, and clean >> all the carbon out of the valve on the compressor that the banjo >> fitting attaches to. If that valve carbons up enough the air cannot >> exit the compressor and pressures/temperatures in the compressor go >> sky high. There is a shear pin that is supposed to break if this >> happens to save your compressor. >> >> >> >> However, I had a shear pin in mine made of (stainless steel ?), >> which failed to break so the pressure/temperature reached a point >> where the piston froze in the cylinder and ripped the compressor >> cylinder right off the compressor body. (It stripped all the nuts >> right off the studs.) I wonder how many others have a shear pin like >> minewas I the only guy to have a bad one? Probably not! >> >> >> >> Disassemble the valve and soak in odorless mineral spirits for a >> couple days to remove all the carbonworks great. It can be a pain to >> take apart, I use a vise and big wrench. Get some new crush washers >> (I think they are 10 and 18 mm I.D.) You can get them here >> cheaphttp://www.mcmaster.com/#standard-crush-washers/=n0n313 >> >> >> >> Try this before you remove the compressor. That is a real PITA!!! >> >> >> >> >> >> >> >> >> >> Read this topic online here: >> >> >> >> http://forums.matronics.com/viewtopic.php?p=401810#401810 >> > >> > >> > >> > "http://forums.matronics.com/" >> target="_blank">http://forums.matronics.cohank you for your generous >> nbsp; -Matt Dralle, List Admin. >> >> >> >> >> * >> >> ================================== >> //www.matronics.com/Navigator?Yak-List >> ================================== >> cs.com >> ================================== >> matronics.com/contribution >> ================================== >> >> * > * > > > * ________________________________ Message 3 _____________________________________ Time: 06:17:00 AM PST US From: "gord" Subject: RE: Yak-List: compressor problems Thank you all for the responses to my request for help on the compressor. I have time to explain a little more now. As it always happens, the problem was undetected until I was ready to start for the Air Show in Waterloo Ontario on Satueday. http://www.waterlooairshow.com/performers/in-the-air . Sunday was fine with lots of nitrogen from the bottle. Fortunately I allowed an extra 5 min just in case. There was a bit of panic when I hit the start button and ... NADA. The pressure was down to about 25. (never let that happen again). After some frantic attempts, pulling the prop through etc I finally just held the button in and it flipped over 1 blade, stopped and flipped one more blade and caught. Thank goodness. The compressor has not been putting out much more that 35 for the last 10 hours or so. Now it is not putting out anything. There is no residual pressure from the snot valve after the flight. The airplane is back in the hangar and I will have a go at it tomorrow. Aside from that little problem the airplane is really performing well and the air show crowds seem to enjoy it. It really is a fabulous Air Show machine. Thanks again for the help ........ Gord Price 519 795 7080 ________________________________ Message 4 _____________________________________ Time: 06:27:37 AM PST US Subject: Yak-List: Say It Ain't So... From: Rico Jaeger Just out of curiosity...I recently received my latest EAA WARBIRDS magazine and while perusing the coverage of Sun N' Fun, noted there was but a single photo of an L-39 w/ a very conspicuous absence of any other Red Star aircraft. Assuming the event was well-attended by the Yak / CJ community, is there a bit of shunning occurring here? Or am I just being a paranoid alarmist? Aren't these aircraft bonified "WARBIRDS" - very active in promoting the sport and the joys of safe, semi-self-governed general aviation? This is not an attempt to stir up a hornet's nest. Maybe the photos just "played out" that way. And I am probably naively jumping to conclusions, but...where is the coverage / acknowledgement? There are Red Star forums, fly-by's, fly-out's, mass arrivals and tons of static representation. So...? -- Rico Jaeger Choir / East High School General Music / Horace Mann ________________________________ Message 5 _____________________________________ Time: 06:57:28 AM PST US Subject: Re: Yak-List: RE: Compressor problem From: doug sapp Or you could just call me. I do try to stock all the small parts to keep us in the air. Just ask for the KY2 compressor kit. It contains all the proper alu crush seals, a new stainless steel poppet valve spring, and a new compressor filter. I also stock new compressors if needed. There is no difference in the M14P and the HS6A compressor other than the "clock" position of the poppet, which is easily changed. Doug On Sun, Jun 2, 2013 at 9:38 AM, Frank Stelwagon wrote: > ** > If you have a good auto shop or "speed Shop" available they will have > crush washers. Most of the newer GM cars use a metric banjo fitting at the > brake calipers. > > Frank > > * > > * > > ________________________________ Message 6 _____________________________________ Time: 07:09:40 AM PST US Subject: Re: Yak-List: compressor problems From: doug sapp Gord, Before spending a grand on a new compressor, check the following: Take a rubber glove and stretch it over the top of the compressor and rotate the prop 8 to 10 blades to see if it sucks down on the filter. if yes you problem is most likely not in the compressor. Check for leaks down stream, a stuck poppet valve or a broken spring. Remove the filter and screens and watch the little nut in the middle as you rotate the engine, is it moving? if not then you may have a sheared pin, again your compressor is OK, just replace the pin. Not a fun job. I don't have the shear pins in stock, but I think Jill at M14P or Geo Coy might. Call if I can be of help 509-826-4610. Best, Doug Sapp On Sat, Jun 1, 2013 at 7:02 PM, Gord wrote: > > Looks like I need a compressor overhaul or replacement. The pressure is > not getting over 3. Does anyone have a compressor for sale or a kit to > overhaul. > Gord with Yak 50 SN 01 > > ________________________________ Message 7 _____________________________________ Time: 07:39:59 AM PST US Subject: RE: Yak-List: compressor problems From: "Bitterlich, Mark G CIV NAVAIR, WD" Gord, Just a few comments. 1. DARN GOOD ADVICE from Doug Sapp !!! By the way Doug, I never heard of that particular trick before or maybe I did... Dennis? Anyway, I'll remember that one for sure! 2. Gord, during the 13 years I have owned my YAK-50, I have had situations where the pressure gage did not pump up, or remain up, or whatever else, a whole BUNCH of times! Hundreds of hours and hundreds of flights. The engine compressor has never been replaced during that entire time. It has *ALWAYS* turned out to be a leak of some kind. One good hint you gave in another message was that there was little to no air in the snot valve. Compressor could be bad as Doug detailed. But .... Also the banjo fitting, which I believe has already been mentioned. Next, the rigid line that goes from the compressor banjo fitting TO the snot valve. I have seen a bunch of them crack and then leak. Happens ALL the time. I replaced mine with a flexible steel braided hose off a Sukhoi. Cracked flare in any of the lines. By the way, if you happen to be incorrect about the snot valve and the amount of air that is released when you check it, the possibilities expand to a LARGE number of additional possibilities. Bottom line, a leak of some kind. Yes, it could be a compressor, but it sure would not be something I would jump on first. Mark -----Original Message----- From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of doug sapp Sent: Monday, June 03, 2013 10:08 Subject: Re: Yak-List: compressor problems Gord, Before spending a grand on a new compressor, check the following: Take a rubber glove and stretch it over the top of the compressor and rotate the prop 8 to 10 blades to see if it sucks down on the filter. if yes you problem is most likely not in the compressor. Check for leaks down stream, a stuck poppet valve or a broken spring. Remove the filter and screens and watch the little nut in the middle as you rotate the engine, is it moving? if not then you may have a sheared pin, again your compressor is OK, just replace the pin. Not a fun job. I don't have the shear pins in stock, but I think Jill at M14P or Geo Coy might. Call if I can be of help 509-826-4610. Best, Doug Sapp On Sat, Jun 1, 2013 at 7:02 PM, Gord wrote: Looks like I need a compressor overhaul or replacement. The pressure is not getting over 3. Does anyone have a compressor for sale or a kit to overhaul. Gord with Yak 50 SN 01 =================================== rget="_blank">http://www.matronics.com/Navigator?Yak-List =================================== http://forums.matronics.com =================================== le, List Admin. ="_blank">http://www.matronics.com/contribution =================================== ________________________________ Message 8 _____________________________________ Time: 09:26:17 AM PST US From: bill wade Subject: Re: Yak-List: Engine Start Mystery Sam if you had a valve stuck open on the cylinder or just not seated well y our start would stop on that cylinder and the start=C2-air would escape t hrough the open valve exhaust or intake as the air is injected into the cyl inder on the power stroke. As for spinning fast and not starting=C2-I don 't have a clue.=0ABill Wade=0A =0A=0A________________________________=0A Fr om: Sam Sax =0ATo: yak-list@matronics.com =0ASent: Sunday, June 2, 2013 10:43 PM=0ASubject: Yak-List: Engine Start Mystery=0A =0A=0A=0AThis is a "good" one... I fly my CJ6 with the M-14p engine over a decade and have never seen or heard of this happening.=C2- I'd appreciate any ideas shedding light on this mystery...=0A=0AEarlier today upon return ing from a routine acro practice flight, taxied to the fuel pump and perfor med a normal shutdown.=0A=0AAfter fueling and as a practice before each sta rt, I have my GIB rotate the prop by hand a few blades as I prime (a little when engine is hot).=C2- My GIB reported that the first two blades were tight with normal feel of compression but the next blade was very soft.=C2 - I didn=99t think much of it and asked him to hop in and I commenc ed with normal engine start procedure.=0AUpon pressing the Air-Start button , the blades rotated in an amazingly fast rate - much faster than normal st art rotation speed - as if there was no compression in the cylinders...=C2 - Moreover, there was no ignition whatsoever during this fast rotation. =C2- I released the start button, waited a minute and tried again - same high speed rotation and no ignition...=0A=0AAt this time I got very worried and thought that the rear segment of the crankshaft somehow sheared off (o n shutdown??)!=C2- Spent about 10 minutes with my knowledgeable GIB tryi ng to figure out what could have happened.=C2- At that point, I asked him to try rotating the prop by hand and see if ANY of the cylinders have comp ression.=C2- As he was turning the prop by hand, I could see his strain a s he rotates blade by blade - he proceeded to report feeling normal compres sion resistance on all blades.=C2- At this point I wanted to attempt anot her start.=C2- GIB was back in the rear cockpit and I pressed the starter button - engine started on the second blade (as it normally does)!=C2- I have the JP Instrument 9 Cylinder unit where I can see CHT and EGT for al l 9 cylinders - All showing normal!=0ATaxied back to hangar - Performed a M agneto check - Normal.=C2- Oil, Fuel pressures and temps - normal.=C2- I shut down again and re-started two additional times in an effort to dupli cate the problem...=C2- Started perfectly normal each time.=0A=0ASo... wh at the hell happened there?=C2- I am thinking a stuck intake valve but on e stuck valve will not make the prop spin that fast on starting...=C2- Tw o stuck valves?=C2- Three??=C2- Can that happen?=C2- If one did stick , why wasn't there any ignition on the other cylinders?=C2- If the stick ing valve was the intake valve on #7 cylinder (that gets most of the Primin g flow), I can see no ignition condition but this is only a guess.=0A=0ASom e engine info:=0AM14-P standard (360HP)=0ATotal time:=C2- 765 hours sinc e new=0ALast compression check (4 months ago): 77 - 78 all cylinders=0AEngi ne oil: Philips 25W60 multi viscosity oil=0ALast Valve Lash adjustment: 80 hours ago=0ASystem Air Pressure at first re-start attempt: 42 ATM, at last (Fifth start) 28 ATM=0ALocation, Hot Miami, FL=0A=0AAnyone seen anything li ke this before? Ideas?=0A=0AThank you in advance for any input,=0A=0ASam Sa =C2- =C2- =C2- =C2- =C2- =C2- =C2- =C2- =C2- =C2- -Matt ============ ________________________________ Message 9 _____________________________________ Time: 05:53:10 PM PST US From: cjpilot710@aol.com Subject: Re: Yak-List: Engine Start Mystery I agree with Bill if you had a valve stuck open, the engine would not kick passed that cylinder. I had this happen on the HS6a with a burnt exhaust valve. As for the super rotation - - - I am totally stumped. Pappy In a message dated 6/3/2013 12:26:32 P.M. Eastern Daylight Time, bwade154@yahoo.com writes: Sam if you had a valve stuck open on the cylinder or just not seated well your start would stop on that cylinder and the start air would escape through the open valve exhaust or intake as the air is injected into the cylinder on the power stroke. As for spinning fast and not starting I don' t have a clue. Bill Wade From: Sam Sax Sent: Sunday, June 2, 2013 10:43 PM Subject: Yak-List: Engine Start Mystery (mailto:cd001633@mindspring.com) > This is a "good" one... I fly my CJ6 with the M-14p engine over a decade and have never seen or heard of this happening. I'd appreciate any ideas shedding light on this mystery... Earlier today upon returning from a routine acro practice flight, taxied to the fuel pump and performed a normal shutdown. After fueling and as a practice before each start, I have my GIB rotate the prop by hand a few blades as I prime (a little when engine is hot). M y GIB reported that the first two blades were tight with normal feel of compression but the next blade was very soft. I didn=99t think much of it and asked him to hop in and I commenced with normal engine start procedure. Upon pressing the Air-Start button, the blades rotated in an amazingly fast rate - much faster than normal start rotation speed - as if there was no compression in the cylinders... Moreover, there was no ignition whatsoeve r during this fast rotation. I released the start button, waited a minute and tried again - same high speed rotation and no ignition... At this time I got very worried and thought that the rear segment of the crankshaft somehow sheared off (on shutdown??)! Spent about 10 minutes wi th my knowledgeable GIB trying to figure out what could have happened. At that point, I asked him to try rotating the prop by hand and see if ANY of the cylinders have compression. As he was turning the prop by hand, I cou ld see his strain as he rotates blade by blade - he proceeded to report feeling normal compression resistance on all blades. At this point I want ed to attempt another start. GIB was back in the rear cockpit and I pressed the starter button - engine started on the second blade (as it normally does)! I have the JP Instrument 9 Cylinder unit where I can see CHT and EGT for all 9 cylinders - All showing normal! Taxied back to hangar - Performed a Magneto check - Normal. Oil, Fuel pressures and temps - normal. I shut down again and re-started two additi onal times in an effort to duplicate the problem... Started perfectly normal each time. So... what the hell happened there? I am thinking a stuck intake valve but one stuck valve will not make the prop spin that fast on starting... Two stuck valves? Three?? Can that happen? If one did stick, why wasn't there any ignition on the other cylinders? If the sticking valve was the intake valve on #7 cylinder (that gets most of the Priming flow), I can se e no ignition condition but this is only a guess. Some engine info: M14-P standard (360HP) Total time: 765 hours since new Last compression check (4 months ago): 77 - 78 all cylinders Engine oil: Philips 25W60 multi viscosity oil Last Valve Lash adjustment: 80 hours ago System Air Pressure at first re-start attempt: 42 ATM, at last (Fifth start) 28 ATM Location, Hot Miami, FL Anyone seen anything like this before? Ideas? Thank you in advance for any input, Sam Sax Miami ties such as List Un/Subscrip-= Photoshare, and much mum/Navigator?Yak-List" target="_blank">http://www.matronics.com/Navigat or?p; --> _http://forums.matr -Matt Dralle, List======= = _ (http://forums.matronics.com/) ________________________________ Message 10 ____________________________________ Time: 07:01:55 PM PST US From: "Frank Stelwagon" Subject: Yak-List: RE: Engine start mystery I wonder, since the M14 is usually started with the mags off until it fires if the engine was actually running on the shower of sparks in the hot cylinder environment. The initial cylinder pull through with the normal compression then the soft cylinder may have been the cylinder actually burning residual fuel. That would be similar to the early days of emission controls when the engines tended to run on after shut down. This was due to the high heat and the carburetor allowing fuel into the engine. Remember the shower of sparks is retarded and with the hot engine it may have actually been running. Would have been interesting if the mags had been turned on while it was spinning fast, probably would have started fine. ________________________________ Message 11 ____________________________________ Time: 07:53:43 PM PST US Subject: Re: Yak-List: Engine Start Mystery From: "Roger Kemp M.D." A freek alignment of the compression rings with the oil scavenge rings comes to mind. As possible air start valve leaking. Any oil spray around the base s of your air start valves? loose spark plugs will allow air leaking also. N ot likely I know. Check the ceramic bases on your plugs also. You could have blown the cores on a few of the plugs to if they are RU or Chinese. A fully blown core will be a blow torch I know but not some that are cracked. Just a few more thoughts on the the subject. Doc` Sent from my iPad On Jun 3, 2013, at 7:50 PM, cjpilot710@aol.com wrote: > I agree with Bill if you had a valve stuck open, the engine would not kick passed that cylinder. I had this happen on the HS6a with a burnt exhaust v alve. As for the super rotation - - - I am totally stumped. Pappy > > > In a message dated 6/3/2013 12:26:32 P.M. Eastern Daylight Time, bwade154@ yahoo.com writes: > Sam if you had a valve stuck open on the cylinder or just not seated well y our start would stop on that cylinder and the start air would escape through the open valve exhaust or intake as the air is injected into the cylinder o n the power stroke. As for spinning fast and not starting I don't have a clu e. > Bill Wade > > From: Sam Sax > To: yak-list@matronics.com > Sent: Sunday, June 2, 2013 10:43 PM > Subject: Yak-List: Engine Start Mystery > > > > This is a "good" one... I fly my CJ6 with the M-14p engine over a decade a nd have never seen or heard of this happening. I'd appreciate any ideas s hedding light on this mystery... > > Earlier today upon returning from a routine acro practice flight, taxied t o the fuel pump and performed a normal shutdown. > > After fueling and as a practice before each start, I have my GIB rotate th e prop by hand a few blades as I prime (a little when engine is hot). My GI B reported that the first two blades were tight with normal feel of compress ion but the next blade was very soft. I didn=99t think much of it and asked him to hop in and I commenced with normal engine start procedure. > Upon pressing the Air-Start button, the blades rotated in an amazingly fas t rate - much faster than normal start rotation speed - as if there was no c ompression in the cylinders... Moreover, there was no ignition whatsoever d uring this fast rotation. I released the start button, waited a minute and t ried again - same high speed rotation and no ignition... > > At this time I got very worried and thought that the rear segment of the c rankshaft somehow sheared off (on shutdown??)! Spent about 10 minutes with m y knowledgeable GIB trying to figure out what could have happened. At that p oint, I asked him to try rotating the prop by hand and see if ANY of the cyl inders have compression. As he was turning the prop by hand, I could see hi s strain as he rotates blade by blade - he proceeded to report feeling norma l compression resistance on all blades. At this point I wanted to attempt a nother start. GIB was back in the rear cockpit and I pressed the starter bu tton - engine started on the second blade (as it normally does)! I have the JP Instrument 9 Cylinder unit where I can see CHT and EGT for all 9 cylinde rs - All showing normal! > Taxied back to hangar - Performed a Magneto check - Normal. Oil, Fuel pre ssures and temps - normal. I shut down again and re-started two additional t imes in an effort to duplicate the problem... Started perfectly normal each time. > > So... what the hell happened there? I am thinking a stuck intake valve bu t one stuck valve will not make the prop spin that fast on starting... Two s tuck valves? Three?? Can that happen? If one did stick, why wasn't there a ny ignition on the other cylinders? If the sticking valve was the intake va lve on #7 cylinder (that gets most of the Priming flow), I can see no igniti on condition but this is only a guess. > > Some engine info: > M14-P standard (360HP) > Total time: 765 hours since new > Last compression check (4 months ago): 77 - 78 all cylinders > Engine oil: Philips 25W60 multi viscosity oil > Last Valve Lash adjustment: 80 hours ago > System Air Pressure at first re-start attempt: 42 ATM, at last (Fifth star t) 28 ATM > Location, Hot Miami, FL > > Anyone seen anything like this before? Ideas? > > Thank you in advance for any input, > > Sam Sax > Miami ties such as List Un/Subscrip-= Photoshare, and much mum/Navigator ?Yak-List" target="_blank">http://www.matronics.com/Navigator?p; --> http: //forums.matr -Matt Dralle, List======= = > > > > > > > > ="http://www.matronics.com/Navigator?Yak-List">http://www.matronics.com/ Navigator?Yak-List > s.matronics.com/">http://forums.matronics.com > p://www.matronics.com/contribution">http://www.matronics.com/contribution > > > ========================== ========= ========================== ========= ========================== ========= ========================== ========= > ________________________________ Message 12 ____________________________________ Time: 07:53:43 PM PST US Subject: Re: Yak-List: Say It Ain't So... From: "Roger Kemp M.D." Welcome to the Red Headed Step Children Club! Unless you fly American or an A llied aircraft you just are not in the club. I say screw them as I laugh all the way to and from the fuel pumps as my sor tie rate beats them stupid!` Doc Sent from my iPad On Jun 3, 2013, at 8:25 AM, Rico Jaeger wrote: > Just out of curiosity...I recently received my latest EAA WARBIRDS magazin e and while perusing the coverage of Sun N' Fun, noted there was but a singl e photo of an L-39 w/ a very conspicuous absence of any other Red Star aircr aft. Assuming the event was well-attended by the Yak / CJ community, is ther e a bit of shunning occurring here? Or am I just being a paranoid alarmist? A ren't these aircraft bonified "WARBIRDS" - very active in promoting the spor t and the joys of safe, semi-self-governed general aviation? This is not an a ttempt to stir up a hornet's nest. Maybe the photos just "played out" that w ay. And I am probably naively jumping to conclusions, but...where is the cov erage / acknowledgement? There are Red Star forums, fly-by's, fly-out's, mas s arrivals and tons of static representation. So...? > > -- > Rico Jaeger > Choir / East High School > General Music / Horace Mann > > ========================== ========= ========================== ========= ========================== ========= ========================== ========= > ________________________________ Message 13 ____________________________________ Time: 08:02:31 PM PST US From: "Sam Sax" Subject: Yak-List: Engine Start Mystery Thanks Pappy! I am scratching my head on this fast rotation issue BIG Time! I may have not primed enough thinking of a warm engine (only two strokes, which were normally enough) but let=99s say not enough priming in this case =93 But why the fast rotation? Air Tank Pressure was 42 ATM on the first fast spinning attempt and 38 on the second fast spinning attempt. Third attempt was successful with additional Priming and slower (normal) rotation speed =93 35 ATM Could anything shifted in the Air Distributor alignment only to return to normal a few minutes later? I told you this Mystery Challenge will be hard to crack! J Any ideas? Anyone? Sam From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of cjpilot710@aol.com Sent: Monday, June 03, 2013 8:51 PM Subject: Re: Yak-List: Engine Start Mystery I agree with Bill if you had a valve stuck open, the engine would not kick passed that cylinder. I had this happen on the HS6a with a burnt exhaust valve. As for the super rotation - - - I am totally stumped. Pappy In a message dated 6/3/2013 12:26:32 P.M. Eastern Daylight Time, bwade154@yahoo.com writes: Sam if you had a valve stuck open on the cylinder or just not seated well your start would stop on that cylinder and the start air would escape through the open valve exhaust or intake as the air is injected into the cylinder on the power stroke. As for spinning fast and not starting I don't have a clue. Bill Wade From: Sam Sax Sent: Sunday, June 2, 2013 10:43 PM Subject: Yak-List: Engine Start Mystery This is a "good" one... I fly my CJ6 with the M-14p engine over a decade and have never seen or heard of this happening. I'd appreciate any ideas shedding light on this mystery... Earlier today upon returning from a routine acro practice flight, taxied to the fuel pump and performed a normal shutdown. After fueling and as a practice before each start, I have my GIB rotate the prop by hand a few blades as I prime (a little when engine is hot). My GIB reported that the first two blades were tight with normal feel of compression but the next blade was very soft. I didn=99t think much of it and asked him to hop in and I commenced with normal engine start procedure. Upon pressing the Air-Start button, the blades rotated in an amazingly fast rate - much faster than normal start rotation speed - as if there was no compression in the cylinders... Moreover, there was no ignition whatsoever during this fast rotation. I released the start button, waited a minute and tried again - same high speed rotation and no ignition... At this time I got very worried and thought that the rear segment of the crankshaft somehow sheared off (on shutdown??)! Spent about 10 minutes with my knowledgeable GIB trying to figure out what could have happened. At that point, I asked him to try rotating the prop by hand and see if ANY of the cylinders have compression. As he was turning the prop by hand, I could see his strain as he rotates blade by blade - he proceeded to report feeling normal compression resistance on all blades. At this point I wanted to attempt another start. GIB was back in the rear cockpit and I pressed the starter button - engine started on the second blade (as it normally does)! I have the JP Instrument 9 Cylinder unit where I can see CHT and EGT for all 9 cylinders - All showing normal! Taxied back to hangar - Performed a Magneto check - Normal. Oil, Fuel pressures and temps - normal. I shut down again and re-started two additional times in an effort to duplicate the problem... Started perfectly normal each time. So... what the hell happened there? I am thinking a stuck intake valve but one stuck valve will not make the prop spin that fast on starting... Two stuck valves? Three?? Can that happen? If one did stick, why wasn't there any ignition on the other cylinders? If the sticking valve was the intake valve on #7 cylinder (that gets most of the Priming flow), I can see no ignition condition but this is only a guess. Some engine info: M14-P standard (360HP) Total time: 765 hours since new Last compression check (4 months ago): 77 - 78 all cylinders Engine oil: Philips 25W60 multi viscosity oil Last Valve Lash adjustment: 80 hours ago System Air Pressure at first re-start attempt: 42 ATM, at last (Fifth start) 28 ATM Location, Hot Miami, FL Anyone seen anything like this before? Ideas? Thank you in advance for any input, Sam Sax Miami ties such as List Un/Subscrip-= Photoshare, and much mum/Navigator?Yak-List" target="_blank">http://www.matronics.com/Navigator?p; --> http://forums.matr -Matt Dralle, List======== ="http://www.matronics.com/Navigator?Yak-List">http://www.matronics.com /Navigator?Yak-List s.matronics.com/">http://forums.matronics.com p://www.matronics.com/contribution">http://www.matronics.com/contribution ________________________________ Message 14 ____________________________________ Time: 08:10:08 PM PST US From: "Sam Sax" Subject: Yak-List: RE: Engine start mystery Hi Frank, Thank you for responding. Interesting point - I believe you are referring to a "Dieseling Effect" where combustion can occur in a hot cylinder on compression stroke when fuel or fuel vapor is present. I am thinking that if this what occurred I would have heard or seen some evidence of it, like popping or at least light smoke from the exhaust. Also, the engine was at least 15 minutes if not more from shut down (at the Gas Pump), so although very warm, it was not as hot to facilitate Dieseling, I believe. Sam From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of Frank Stelwagon Sent: Monday, June 03, 2013 10:00 PM Subject: Yak-List: RE: Engine start mystery I wonder, since the M14 is usually started with the mags off until it fires if the engine was actually running on the shower of sparks in the hot cylinder environment. The initial cylinder pull through with the normal compression then the soft cylinder may have been the cylinder actually burning residual fuel. That would be similar to the early days of emission controls when the engines tended to run on after shut down. This was due to the high heat and the carburetor allowing fuel into the engine. Remember the shower of sparks is retarded and with the hot engine it may have actually been running. Would have been interesting if the mags had been turned on while it was spinning fast, probably would have started fine. ________________________________ Message 15 ____________________________________ Time: 08:21:07 PM PST US From: "Sam Sax" Subject: RE: Yak-List: Engine Start Mystery Thanks Doc =93 I appreciate the input. I will definitely followup on checking all the spark plugs (Chinese) as I will on other basic engine tests such as Compression testing each cylinder, Valve Lash / Rockers, checking the Oil Filter and Screen even Cylinder base bolts (common problem in the Housai, not the M-14). Still, I can=99t explain how any of the good suggestions for the problem so far on the List, if true, disappeared on the third engine start attempt where engine started and ran normally throughout the entire Power/RPM range and subsequent shut downs and re-starts =93 all normal The Mystery continues Sam From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@matronics.com] On Behalf Of Roger Kemp M.D. Sent: Monday, June 03, 2013 10:47 PM Subject: Re: Yak-List: Engine Start Mystery A freek alignment of the compression rings with the oil scavenge rings comes to mind. As possible air start valve leaking. Any oil spray around the bases of your air start valves? loose spark plugs will allow air leaking also. Not likely I know. Check the ceramic bases on your plugs also. You could have blown the cores on a few of the plugs to if they are RU or Chinese. A fully blown core will be a blow torch I know but not some that are cracked. Just a few more thoughts on the the subject. Doc` Sent from my iPad On Jun 3, 2013, at 7:50 PM, cjpilot710@aol.com wrote: I agree with Bill if you had a valve stuck open, the engine would not kick passed that cylinder. I had this happen on the HS6a with a burnt exhaust valve. As for the super rotation - - - I am totally stumped. Pappy In a message dated 6/3/2013 12:26:32 P.M. Eastern Daylight Time, bwade154@yahoo.com writes: Sam if you had a valve stuck open on the cylinder or just not seated well your start would stop on that cylinder and the start air would escape through the open valve exhaust or intake as the air is injected into the cylinder on the power stroke. As for spinning fast and not starting I don't have a clue. Bill Wade From: Sam Sax Sent: Sunday, June 2, 2013 10:43 PM Subject: Yak-List: Engine Start Mystery This is a "good" one... I fly my CJ6 with the M-14p engine over a decade and have never seen or heard of this happening. I'd appreciate any ideas shedding light on this mystery... Earlier today upon returning from a routine acro practice flight, taxied to the fuel pump and performed a normal shutdown. After fueling and as a practice before each start, I have my GIB rotate the prop by hand a few blades as I prime (a little when engine is hot). My GIB reported that the first two blades were tight with normal feel of compression but the next blade was very soft. I didn=99t think much of it and asked him to hop in and I commenced with normal engine start procedure. Upon pressing the Air-Start button, the blades rotated in an amazingly fast rate - much faster than normal start rotation speed - as if there was no compression in the cylinders... Moreover, there was no ignition whatsoever during this fast rotation. I released the start button, waited a minute and tried again - same high speed rotation and no ignition... At this time I got very worried and thought that the rear segment of the crankshaft somehow sheared off (on shutdown??)! Spent about 10 minutes with my knowledgeable GIB trying to figure out what could have happened. At that point, I asked him to try rotating the prop by hand and see if ANY of the cylinders have compression. As he was turning the prop by hand, I could see his strain as he rotates blade by blade - he proceeded to report feeling normal compression resistance on all blades. At this point I wanted to attempt another start. GIB was back in the rear cockpit and I pressed the starter button - engine started on the second blade (as it normally does)! I have the JP Instrument 9 Cylinder unit where I can see CHT and EGT for all 9 cylinders - All showing normal! Taxied back to hangar - Performed a Magneto check - Normal. Oil, Fuel pressures and temps - normal. I shut down again and re-started two additional times in an effort to duplicate the problem... Started perfectly normal each time. So... what the hell happened there? I am thinking a stuck intake valve but one stuck valve will not make the prop spin that fast on starting... Two stuck valves? Three?? Can that happen? If one did stick, why wasn't there any ignition on the other cylinders? If the sticking valve was the intake valve on #7 cylinder (that gets most of the Priming flow), I can see no ignition condition but this is only a guess. Some engine info: M14-P standard (360HP) Total time: 765 hours since new Last compression check (4 months ago): 77 - 78 all cylinders Engine oil: Philips 25W60 multi viscosity oil Last Valve Lash adjustment: 80 hours ago System Air Pressure at first re-start attempt: 42 ATM, at last (Fifth start) 28 ATM Location, Hot Miami, FL Anyone seen anything like this before? Ideas? Thank you in advance for any input, Sam Sax Miami ties such as List Un/Subscrip-= Photoshare, and much mum/Navigator?Yak-List" target="_blank">http://www.matronics.com/Navigator?p; --> http://forums.matr -Matt Dralle, List======== ="http://www.matronics.com/Navigator?Yak-List">http://www.matronics.com /Navigator?Yak-List s.matronics.com/">http://forums.matronics.com p://www.matronics.com/contribution">http://www.matronics.com/contribution ========= //www.matronics.com/Navigator?Yak-List ========= cs.com ========= matronics.com/contribution ========= ________________________________ Message 16 ____________________________________ Time: 09:28:29 PM PST US Subject: Re: Yak-List: Engine Start Mystery From: "Roger Kemp M.D." Agreed Sam, it has me scratching my head too! Doc Sent from my iPad On Jun 3, 2013, at 10:19 PM, "Sam Sax" wrote: > Thanks Doc =93 I appreciate the input. > > I will definitely followup on checking all the spark plugs (Chinese) as I w ill on other basic engine tests such as Compression testing each cylinder, V alve Lash / Rockers, checking the Oil Filter and Screen even Cylinder base b olts (common problem in the Housai, not the M-14). > > Still, I can=99t explain how any of the good suggestions for the pro blem so far on the List, if true, disappeared on the third engine start atte mpt where engine started and ran normally throughout the entire Power/RPM ra nge and subsequent shut downs and re-starts =93 all normal > > The Mystery continues > > Sam > > > > > > From: owner-yak-list-server@matronics.com [mailto:owner-yak-list-server@ma tronics.com] On Behalf Of Roger Kemp M.D. > Sent: Monday, June 03, 2013 10:47 PM > To: yak-list@matronics.com > Subject: Re: Yak-List: Engine Start Mystery > > A freek alignment of the compression rings with the oil scavenge rings com es to mind. As possible air start valve leaking. Any oil spray around the ba ses of your air start valves? loose spark plugs will allow air leaking also. Not likely I know. Check the ceramic bases on your plugs also. You could ha ve blown the cores on a few of the plugs to if they are RU or Chinese. A ful ly blown core will be a blow torch I know but not some that are cracked. > Just a few more thoughts on the the subject. > Doc` > > Sent from my iPad > > On Jun 3, 2013, at 7:50 PM, cjpilot710@aol.com wrote: > > I agree with Bill if you had a valve stuck open, the engine would not kick passed that cylinder. I had this happen on the HS6a with a burnt exhaust v alve. As for the super rotation - - - I am totally stumped. Pappy > > > In a message dated 6/3/2013 12:26:32 P.M. Eastern Daylight Time, bwade154@ yahoo.com writes: > Sam if you had a valve stuck open on the cylinder or just not seated well y our start would stop on that cylinder and the start air would escape through the open valve exhaust or intake as the air is injected into the cylinder o n the power stroke. As for spinning fast and not starting I don't have a clu e. > Bill Wade > > From: Sam Sax > To: yak-list@matronics.com > Sent: Sunday, June 2, 2013 10:43 PM > Subject: Yak-List: Engine Start Mystery > > > > This is a "good" one... I fly my CJ6 with the M-14p engine over a decade a nd have never seen or heard of this happening. I'd appreciate any ideas she dding light on this mystery... > > Earlier today upon returning from a routine acro practice flight, taxied t o the fuel pump and performed a normal shutdown. > > After fueling and as a practice before each start, I have my GIB rotate th e prop by hand a few blades as I prime (a little when engine is hot). My GI B reported that the first two blades were tight with normal feel of compress ion but the next blade was very soft. I didn=99t think much of it and asked him to hop in and I commenced with normal engine start procedure. > Upon pressing the Air-Start button, the blades rotated in an amazingly fas t rate - much faster than normal start rotation speed - as if there was no c ompression in the cylinders... Moreover, there was no ignition whatsoever d uring this fast rotation. I released the start button, waited a minute and t ried again - same high speed rotation and no ignition... > > At this time I got very worried and thought that the rear segment of the c rankshaft somehow sheared off (on shutdown??)! Spent about 10 minutes with m y knowledgeable GIB trying to figure out what could have happened. At that p oint, I asked him to try rotating the prop by hand and see if ANY of the cyl inders have compression. As he was turning the prop by hand, I could see hi s strain as he rotates blade by blade - he proceeded to report feeling norma l compression resistance on all blades. At this point I wanted to attempt a nother start. GIB was back in the rear cockpit and I pressed the starter bu tton - engine started on the second blade (as it normally does)! I have the JP Instrument 9 Cylinder unit where I can see CHT and EGT for all 9 cylinde rs - All showing normal! > Taxied back to hangar - Performed a Magneto check - Normal. Oil, Fuel pre ssures and temps - normal. I shut down again and re-started two additional t imes in an effort to duplicate the problem... Started perfectly normal each time. > > So... what the hell happened there? I am thinking a stuck intake valve bu t one stuck valve will not make the prop spin that fast on starting... Two s tuck valves? Three?? Can that happen? If one did stick, why wasn't there a ny ignition on the other cylinders? If the sticking valve was the intake va lve on #7 cylinder (that gets most of the Priming flow), I can see no igniti on condition but this is only a guess. > > Some engine info: > M14-P standard (360HP) > Total time: 765 hours since new > Last compression check (4 months ago): 77 - 78 all cylinders > Engine oil: Philips 25W60 multi viscosity oil > Last Valve Lash adjustment: 80 hours ago > System Air Pressure at first re-start attempt: 42 ATM, at last (Fifth star t) 28 ATM > Location, Hot Miami, FL > > Anyone seen anything like this before? Ideas? > > Thank you in advance for any input, > > Sam Sax > Miami ties such as List Un/Subscrip-= Photoshare, and much mum/Navigator ?Yak-List" target="_blank">http://www.matronics.com/Navigator?p; --> http: //forums.matr -Matt Dralle, List======= = > > > > > > > > ="http://www.matronics.com/Navigator?Yak-List">http://www.matronics.com/ Navigator?Yak-List > s.matronics.com/">http://forums.matronics.com > p://www.matronics.com/contribution">http://www.matronics.com/contribution > > > > ========================= ========= > //www.matronics.com/Navigator?Yak-List > ========================= ========= > cs.com > ========================= ========= > matronics.com/contribution > ========================= ========= > > > > http://www.matronics.com/Navigator?Yak-List > http://forums.matronics.com > http://www.matronics.com/contribution > > > ========================== ========= ========================== ========= ========================== ========= ========================== ========= > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message yak-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Yak-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/yak-list Browse Digests http://www.matronics.com/digest/yak-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.