---------------------------------------------------------- Continental-List Digest Archive --- Total Messages Posted Mon 07/29/13: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:25 AM - Re: Carb ice, or vapor lock? (Brian) 2. 05:29 AM - Re: Re: Carb ice, or vapor lock? (FLYaDIVE) ________________________________ Message 1 _____________________________________ Time: 04:25:23 AM PST US Subject: Re: Continental-List: Carb ice, or vapor lock? From: Brian Five hours in the Texas sun, I would put money on the vapor lock theory. Your engine compartment was thoroughly heat-soaked. Brian in Brazil ________________________________ Message 2 _____________________________________ Time: 05:29:06 AM PST US Subject: Re: Continental-List: Re: Carb ice, or vapor lock? From: FLYaDIVE Jimmy: I removed the responses that were answered and no longer pose a question to the final result. Please read on. *Barry* On Sun, Jul 28, 2013 at 8:08 PM, Jimmy Young wrote: > > > Barry wrote: > > > 3 - WHY DID YOU NOT LEAN? > > No good reason, other than I've been advised that unless I'm flying above > 5000' regularly, I don't need to. I usually fly at less than 3000' msl mo st > of the time. > > [Barry] - The information you were given, which was also given in part to > most of us as new pilots is incorrect. The basic rule was 'lean at and > above 3000 feet'. What was missing from the statement or misunderstood > due to your limited experience at the time was 3000 feet Density > Altitude. This makes it a almost LEAN all the time, since even my airpor t > on a hot day is 2000 Ft DA. Also consider that as a student most of the > planes DO NOT have EGT & CHT gauges. AND it is much easier to make a > simple statement than try to explain to a student EGT, CHT and Leaning. > Also plug fouling is a major concern, so the rule has changed to Lean Al l > The Time. If one gets into the good habit of leaning all the time the > action will become as natural as appling power for take-off. > > > 5 - I am not a fan of Gascolators - Just way too many issues with them - > I do=EF=BDbelieve=EF=BDvery strongly in - IN LINE fuel filters. =EF =BDBUT! =EF=BDI doubt it the > Gascolator was the=EF=BDculprit. > > Ok, but what then separates water from your fuel? > [Barry] - Jimmy, this is a huge debatable topic which will never be solved until the Gascolator is made CLEAR, the water dyed and a camera setup to film the fuel/water action. The first rule is: Do not put water into the system. I think this is done very well by the fuel companies. The gascolator does not function as well as it is given credit for. Yes, you will see water collect in it from time to time but, that is more because of its location that the action of its function. IF it was such a great item then why isn't it required by the FAA on EVERY plane? ANYWAY! ! ! ... If you got it ... Use it ... Drain it ... And question: Where is the water coming from? > > > > 7 - Vapor Lock - Is easy to prevent. =EF=BDIt starts with fuel syste m=EF=BDdesign=EF=BD > =EF=BDWhat size fuel line are you using? =EF=BDWhat is the fuel lin e made from? =EF=BDHow > do you have the fuel line routed? How is the overall cooling under the co wl? > > Lines are 3/8" Aeroquip rubber hose with AN socketless fittings, except > FWF it's 3/8" Aeroquip SS braided hose with firesleeve. They are routed > straight from the wing tanks to a tee, to a shut off valve, to the FW > bulkhead pass-thru, to the gascolator, and on to the carb. Pretty standar d > and straight-forward. You ask "how is the overall cooling under the cowl? > I've got temp strips on the mags and the firewall. They have topped out > between 160 & 180 degrees. Don't really know how one could keep that area > cool, as it's purpose is to exhaust engine heat. I have considered runnin g > blast tubes to my mags. > [Barry] - EXCELLENT! Years ago I hooked up a Lab Digital Thermometer to various points under the cowl; I got the exact same readings as you are seeing. A blast tube for the Mags is a good idea as wells as for the plastic COUPLING between the vacuum pump and engine. > > > 8 - From you statement of: "They normally stay between 335 & 360 when > running 2350 rpm. My EGT's were climbing as well. This indicates to me th at > I was running lean, if I am correct." =EF=BDWell you are correct. =EF =BDA CHT of 410 > F is above normal IF you=EF=BDcompare=EF=BDit to past operations. W hat were the EGT > readings at the time? =EF=BDI'd bet below 1400 F=EF=BDprobably=EF =BDmore like 1320 F. > =EF=BDSOoooo what would cause leaning? =EF=BDNOT VAPOR LOCK! =EF =BDWith vapor lock you > loose gas flow and the EGT & CHT goes DOWN. =EF=BDNOT CARB ICE! =EF =BDWith carb ice > you loose fuel flow and EGT & CHT goes DOWN. =EF=BDIf CHT goes Down an d EGT goes > Up --- LQQK at fouled plugs or poor spark. =EF=BDIf RPM cannot be main tained and > CHT goes Up ---LQQK at AIR LEAKS... =EF=BDCarb, Intake Tubes. =EF =BD > > My egt's each register a little different temps in cruise, but they alway s > stay consistent. I had my hands full flying the plane so I wasn't taking > notes, but I do recall when the cht alarm light went off I noticed the > highest egt was 1440 or so which is about 75-100 degrees higher than it > would normally be. So, I had both higher cht's and egt's occuring at the > same time my engine was stumbling & performing poorly. These higher CHT & > EGT's may have been partly caused by my having a pitch-up attitude & slow > airspeed, trying to hold altitude at low power output for an extended > period of time while I was nursing my way to the other airport. This woul d > have obviously reduced the volume of cooling air to the engine. I've > noticed when doing slow flight at 1800 & 1900 rpm, my cht's will get up i n > the mid 300's similar to full cruise due to the same lack of cooling air > volume. > I've got a question for you on this section. You said "With vapor lock, > you loose gas flow and the cht & egt go down." Seems to me the opposite > would occur, since you'd have the same air volume and less gas, thus a > leaned out condition. What am I missing there? > [Barry] - Jimmy, Vapor Lock is another one of those topics that is debatable to infinity. To clarify a bit, as your fuel air statement sounds like you are considering there is an AIR/FUEL mixture/ratio - Vapor Lock occurs in fuel lines. Your question assumes you can have a PARTIAL Vapor Lock. Allowing some fuel to flow. I do not believe in a Partial Vapor Lock. Either you have it or you don't! Think of it this way: If you have a Vapor Lock, it is caused by High Temps EXPANDING the vapor pressure of the fuel. This vapor bubble requires two things: 1> High Temps, enough to cause fuel expansion to a vapor level within a confined space and 2> A SPACE to trap the vapor bubble. This SPACE has to be a Upward or Downward 'U'. It does NOT happen in a straight run. SOoooo, if fuel was to trickle by the Vapor Lock Bubble - - - The fuel would COOL the BUBBLE and the Vapor Lock would go away. Ergo, you can not have a partial Vapor Lock. Either you do or you don't. It is like being only slightly pregnant. > > > > 9 - You did not mention OIL TEMPS? > > They never exceeded 210. On a hot summer day they will settle in between > 200 & 210 at cruise. In the Texas winter, O/T runs 180 -195. I do not hav e > an oil cooler. > [Barry] - WOW! TEXAS and NO COOLER! ! ! Not even for the BEER? That is FANTASTIC temps without a cooler. Just think how much happier your engine would be with a cooler? That is truly a great cooling system you did to the plane. People are fighting to get those temps - Another EXCELLENT JOB. [Barry] - So the question still exists - What caused the loss of power? Wish I was there to LQQK over your system. Could you take some pictures or a SLOW MOVING video of the system and email me? Maybe something will jump out and bite me. Talk to you later, Barry > I appreciate the input, & please let me know what any or all of you think > on these comments. I'm still leaning towards vapor lock. Yesterday, I mad e > a foil-faced insulation blanket and wrapped my gascolator with it. Tied i t > off with cable ties. > > Jimmy Y > Houston ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message continental-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Continental-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/continental-list Browse Digests http://www.matronics.com/digest/continental-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.