pinerunner Posted October 2, 2013 Report Posted October 2, 2013 Winter's coming on here in Maine and I know some who happily fly and some who are grounded for the duration. I flew a little last winter but not below freezing and used preheater. I changed the oil to 80 grade when I started getting temperatures below 50 for the start-up. I've had the notion that my guppy-mouth M20E is over-cooled and that's the source of part of my caution. Any cold weather Mooney flying wisdom out there? Minnesota especially gets cold and has lots of Mooneys and a well-known Mooney center. Are you Minnesota pilots flying at 20 below?
aaronk25 Posted October 2, 2013 Report Posted October 2, 2013 I'm a Rochester mn based pilot and I fly high in the winter and all is good. I even run aeroshell 100 (50w) in the winter but always start preheating when temps are below 50 and for sure at 40f. In cruise at -25f the oil runs 165 and heads a but colder at 280-300. Maybe someone one here can answer the question if the oil coolers have some sort of restricter valve or thermostat type deal as I notice the oil never runs cooler than 165-170 regardless of outside temp. I know lots run 20w-50 and some run 40w, all fine choices but I've found that lighter oils don't stay clung on to the cam as well if the bird sits for some period of time. When I pull the dip stick out it appears that the lighter oil runs off a lot faster than the 50w. I use a Rieff engine heater. I also run cam guard but my main concern is wrecking the cam so I take extra preheat precautions in winter so I can run the heavier oil. My engine thinks its summer time all year . If I'm not at gross I carry my honda 2000 with me which will run my heater 8 hours. 2
Shadrach Posted October 2, 2013 Report Posted October 2, 2013 Guys, What is the thinking behind running a higher straight weight oil for colder temps? Is it the "cling" after shut down? I'm fine with flying when surface temps are in the teens. I actually have a thermstat set up to hold the engine compartment at 55df all winter. Remember, lubrication is more about flow than pressure. Pressure just tells you you've got flow... Even when preheated, 80W seems counter-intuitive. It seems that during ground running the cam might be wanting for lube in that scenario unless your idling at 1500 off the start in which case the the oil system would likely go into bypass with the high viscosity oil not up to operating temp. Not criticizing, just interested!
Shadrach Posted October 2, 2013 Report Posted October 2, 2013 aaronk25, on 02 Oct 2013 - 09:57 AM, said: I'm a Rochester mn based pilot and I fly high in the winter and all is good. I even run aeroshell 100 (50w) in the winter but always start preheating when temps are below 50 and for sure at 40f. In cruise at -25f the oil runs 165 and heads a but colder at 280-300. Maybe someone one here can answer the question if the oil coolers have some sort of restricter valve or thermostat type deal as I notice the oil never runs cooler than 165-170 regardless of outside temp. I know lots run 20w-50 and some run 40w, all fine choices but I've found that lighter oils don't stay clung on to the cam as well if the bird sits for some period of time. When I pull the dip stick out it appears that the lighter oil runs off a lot faster than the 50w. I use a Rieff engine heater. I also run cam guard but my main concern is wrecking the cam so I take extra preheat precautions in winter so I can run the heavier oil. My engine thinks its summer time all year . If I'm not at gross I carry my honda 2000 with me which will run my heater 8 hours. See link. The vernatherm does not direct oil to the cooler until it hits about 160df. If you're flying in cold temps, you really ought to consider a blocking plate on the oilcooler. 160-170 is on the cool side... I personally like to see 200 to 215 which is hard to achieve in the winter. I use aluminum tape to block off a portion of the cooler in the winter. I'm of the opinion that high viscosity straight weight oil and low oil temps are not an optimal combination, but to each their own... http://www.aircraft-specialties.com/valve-assy-temp-cont-oil-cool-53e22144/ 1
Marauder Posted October 2, 2013 Report Posted October 2, 2013 Guys, What is the thinking behind running a higher straight weight oil for colder temps? Is it the "cling" after shut down? I'm fine with flying when surface temps are in the teens. I actually have a thermstat set up to hold the engine compartment at 55df all winter. Remember, lubrication is more about flow than pressure. Pressure just tells you you've got flow... Even when preheated, 80W seems counter-intuitive. It seems that during ground running the cam might be wanting for lube in that scenario unless your idling at 1500 off the start in which case the the oil system would likely go into bypass with the high viscosity oil not up to operating temp. Not criticizing, just interested! I agree. I flew for years in Buffalo and use a multi-viscosity oil. The pre-heat process I followed until last winter was to use a propane pre-heater with an cowl blanket for the engine and a ceramic heater in the cabin. I can't remember where I read it, perhaps a Deakin or Busch article, but they said that starting an engine without a proper pre-heat once, is like putting as much wear on the engine as 500 flight hours. Not sure if that is true, but it made me make sure I pre-heat when the temps are below 40 and that I make sure the engine is warm enough before I attempt to start. I switched over to a Reiff heater this year. Won't miss the propane tanks, ducts and sitting in the cold watching it... 1
Shadrach Posted October 2, 2013 Report Posted October 2, 2013 You would laugh at my "Walmart special" heater set up, but it works pretty well!
BorealOne Posted October 2, 2013 Report Posted October 2, 2013 Bruce Jaeger has a great article on winter flying at http://www.jaegeraviation.com/news/5 I fly year round in Canada's North. I won't launch below -35 ground temp (plastic stuff breaks too easily at those temps) but I see -40 OAT or below in the air pretty routinely. If engine + instruments are properly warmed up, our birds do just fine in the cold. Engine tents, wing covers and preheat are critical - I've got a Tanis engine heater, battery warmers, and a forced air heater for the cabin to keep the instrument panel 'warm'. I run 20/50 year round for oil - works just fine if properly preheated. The oil cooler plate is critical for keeping oil temps around 190-200. I also add a little anhydrous isopropyl to my tanks to reduce the risk of ice forming in the fuel lines. Of course, always remember to always wear proper winter clothing and have good winter survival gear on board.
aaronk25 Posted October 2, 2013 Report Posted October 2, 2013 Guys, What is the thinking behind running a higher straight weight oil for colder temps? Is it the "cling" after shut down? I'm fine with flying when surface temps are in the teens. I actually have a thermstat set up to hold the engine compartment at 55df all winter. Remember, lubrication is more about flow than pressure. Pressure just tells you you've got flow... Even when preheated, 80W seems counter-intuitive. It seems that during ground running the cam might be wanting for lube in that scenario unless your idling at 1500 off the start in which case the the oil system would likely go into bypass with the high viscosity oil not up to operating temp. Not criticizing, just interested! Just the cling effect for me. If the oil and heads are at 100 degrees prior to start 50w should be fine right? My reif is on 24/7 in winter and if I stop for a couple hours you will find my Honda purring next to plane on ramp. I will also be making a oil cooler block off plate to get temps above 165 but my oil analysis showed "0" moisture content too.
Shadrach Posted October 2, 2013 Report Posted October 2, 2013 Just the cling effect for me. If the oil and heads are at 100 degrees prior to start 50w should be fine right? My reif is on 24/7 in winter and if I stop for a couple hours you will find my Honda purring next to plane on ramp. I will also be making a oil cooler block off plate to get temps above 165 but my oil analysis showed "0" moisture content too. Aaron, "fine" is a mater of opinion. I do not know how straight 50W flows at 100df, but my guess is not great. This is an interesting read on how oil performs in an engine at various weights and temps. While not Aviation specific, the theories are the same. My undestanding of how oil acts has changed a lot over the years. I'm pretty much always looking to use the lightest weight oil I can get away with at operating temp to ensure the best lubrication at what is in my opinion the most critical phase of operation for wear...engine start. I run 0-W40 in my road going Flat 6 and 5-W30 in the wife's Mini CooperS (only because that's what her Dad puts in it...one must choose their battles with inlaws). As a data point, I ran 0-W40 in my 98 LEX V8 for the first 100K and switched to 5-W40 to present (218,XXXmiles) no blow by and no added oil in between 10,000-13,000 mile changes. I know these are Auto comparisons, but flow is the key on any engine. I run Phillips X/C 20/50 in the Mooney year round. We tore it down at 880 SMOH for a case crack and everything looked nice, so much so that the IRAN and Case overhaul was under $4K. We put lifters in it, but that was not really necessary; they'd have gone to TBO, but I'm planning on going beyond, so it was a "while you're in there" kind of deal... 1
pinerunner Posted October 2, 2013 Author Report Posted October 2, 2013 I'm a Rochester mn based pilot and I fly high in the winter and all is good. I even run aeroshell 100 (50w) in the winter but always start preheating when temps are below 50 and for sure at 40f. In cruise at -25f the oil runs 165 and heads a but colder at 280-300. Maybe someone one here can answer the question if the oil coolers have some sort of restricter valve or thermostat type deal as I notice the oil never runs cooler than 165-170 regardless of outside temp. I know lots run 20w-50 and some run 40w, all fine choices but I've found that lighter oils don't stay clung on to the cam as well if the bird sits for some period of time. When I pull the dip stick out it appears that the lighter oil runs off a lot faster than the 50w. I use a Rieff engine heater. I also run cam guard but my main concern is wrecking the cam so I take extra preheat precautions in winter so I can run the heavier oil. My engine thinks its summer time all year . If I'm not at gross I carry my honda 2000 with me which will run my heater 8 hours. I was thinking of doing this sort of thing, running 100W in the winter with lots of preheating to take advantage of the cling given that I might fly as little as once a month. I was unsure about 100W at such low temperatures. Have you got a bunch of hours doing this? Have you or anyone else taken an engine all the way through an overhaul running 100W cold? Thanks for the post, by the way. This is exactly the kind of discussion I was looking for.
pinerunner Posted October 2, 2013 Author Report Posted October 2, 2013 Aaron, "fine" is a mater of opinion. I do not know how straight 50W flows at 100df, but my guess is not great. This is an interesting read on how oil performs in an engine at various weights and temps. While not Aviation specific, the theories are the same. My undestanding of how oil acts has changed a lot over the years. I'm pretty much always looking to use the lightest weight oil I can get away with at operating temp to ensure the best lubrication at the what is in my opinion the most critical phase of operation for wear...engine start. I run 0-W40 in my road going Flat 6 and 5-W30 in the wifes Mini CooperS (only because that's what her Dad puts in it...one must choose their battles with inlaws). As a data point, I ran 0-W40 in my 98 LEX V8 for the first 100K and switched to 5-W40 to present (218,XXXmiles) no blow by and no added oil in between 10,000-13,000 mile changes. I know these are Auto comparisons, but flow is the key on any engine. I run Phillips X/C 20/50 in the Mooney year round. We tore it down at 880 SMOH for a case crack and everything looked nice, so much so, that the IRAN and Case overhaul was under $4K. We put lifters in it, but that was not really necessary; they'd have gone to TBO, but I'm planning on going beyond, so it was a "while your in there" kind of deal... I bet you fly it frequently too Shad. That's a key point.
pinerunner Posted October 2, 2013 Author Report Posted October 2, 2013 See link. The vernatherm does not direct oil to the cooler until it hits about 160df. If you're flying in cold temps, you really ought to consider a blocking plate on the oilcooler. 160-170 is on the cool side... I personally like to see 200 to 215 which is hard to achieve in the winter. I use aluminum tape to block off a portion of the cooler in the winter. I'm of the opinion that high viscosity straight weight oil and low oil temps is not an optimal combination, but to each their own... http://www.aircraft-specialties.com/valve-assy-temp-cont-oil-cool-53e22144/ I'd like to know more about using that aluminum tape. Do I need a mechanic in the loop to technically stay airworthy?
Shadrach Posted October 2, 2013 Report Posted October 2, 2013 I bet you fly it frequently too Shad. That's a key point. I try, but I'm as reluctant as the next guy to drag my a$$ out to an unheated hangar on an 18 degree day. It does sit for as much as 5 or 6 weeks at a time on occasion. 100hrs a year is a busy year for us... 50-60 is more the norm.
Shadrach Posted October 2, 2013 Report Posted October 2, 2013 I'd like to know more about using that aluminum tape. Do I need a mechanic in the loop to technically stay airworthy? I cannot advise you on the legality of winterizing your oil cooler with tape. Opinions differ on that subject. I'm more concerned about oil temps. If I get ramp checked, and the bureaucrat has an issue with it, I'll deal with it then... AFAIK, there is no winterization kit for my plane. Even if there is, the Al tape is an elegant and inexpensive solution... Kelly may be able to provide regulatory guidance!
orionflt Posted October 2, 2013 Report Posted October 2, 2013 See link. The vernatherm does not direct oil to the cooler until it hits about 160df. If your flying in cold temps, you really ought to consider a blocking plate on the oilcooler. 160-170 is on the cool side... I personally like to see 200 to 215 which is hard to achieve in the winter. I use aluminum tape to block off a portion of the cooler in the winter. I'm of the opinion that high viscosity straight weight oil and low oil temps is not an optimal combination, but to each their own... http://www.aircraft-specialties.com/valve-assy-temp-cont-oil-cool-53e22144/ Ross, the nominal temp for the Lycoming engine is 180 Deg, the green arc is 100-225 so that puts you up near the top of the range. I'll admit 160-170 is colder then i like to run, but in winter with OATs below freezing that is actually great.
Shadrach Posted October 2, 2013 Report Posted October 2, 2013 Ross, the nominal temp for the Lycoming engine is 180 Deg, the green arc is 100-225 so that puts you up near the top of the range. I'll admit 160-170 is colder then i like to run, but in winter with OATs below freezing that is actually great. Like I said, personal preference. If 180 is what someone wants to shoot for, by all means, but I prefer warmer. I do not think 160 is ever great. This is not to say I am worried about it in the short term, but if that is my max temp in flight, then I'm going to be winterizing the oil cooler before the next flight. 1
pinerunner Posted October 2, 2013 Author Report Posted October 2, 2013 I did come across some nasty pictures of what can happen if the oil cooler not preheated enough and filled with congealed oil. The pressure back-up can deform or even pop it. So if using 100W in winter be very sure about good preheating. Bucsh reccomends Multigrade in winter to his clients and 100W in summer. I'm leaning towards that myself at this point. Along with the cooler tape.
Shadrach Posted October 2, 2013 Report Posted October 2, 2013 I did come across some nasty pictures of what can happen if the oil cooler not preheated enough and filled with congealed oil. The pressure back-up can deform or even pop it. So if using 100W in winter be very sure about good preheating. Bucsh reccomends Multigrade in winter to his clients and 100W in summer. I'm leaning towards that myself at this point. Along with the cooler tape. Yup, same scenario as leaving a hose full of water outside to freeze and then hooking it up to a hot water spigot. It's going to take a while to melt the ice and flow. I believe that our oil systems flow a small amount of oil to the cooler even when the vernatherm is not directing oil to the cooler in order to prevent this, but I'm not positive.
kellym Posted October 3, 2013 Report Posted October 3, 2013 See link. The vernatherm does not direct oil to the cooler until it hits about 160df. If you're flying in cold temps, you really ought to consider a blocking plate on the oilcooler. 160-170 is on the cool side... I personally like to see 200 to 215 which is hard to achieve in the winter. I use aluminum tape to block off a portion of the cooler in the winter. I'm of the opinion that high viscosity straight weight oil and low oil temps is not an optimal combination, but to each their own... http://www.aircraft-specialties.com/valve-assy-temp-cont-oil-cool-53e22144/ I've avoided flying my Mooney at much colder than +20F. However I did operate my previous aircraft for 18 yrs in Fairbanks AK, where I used a -20F cutoff for flying.The vernatherm operation is much misunderstood. Your engine has two passages for oil to travel when oil is cold and both are open. One goes to oil cooler and the other byasses it. The vernatherm expands with temperature and at around 180 it totally shuts off the bypass, unless the passage to the oil cooler is blocked, as in a congealed oil cooler. If the oil cooler is very cold on start up it will be a long time before warm oil makes its way through the cooler. Having part of the cooler blocked may help, preheating the cooler will help. The opening of stock pre-J models won't necessarily cause too much cooling if cowl flaps are adjusted correctly. Airflow through the engine is determined by both opening at front and openning at bottom. When I flew the Mooney at 20 degrees CHTs were around 250-260, but my plane has the Mooney SB etra cooling kit that adds a fixed cowl flap. Oil temps were about 180. I recommend pre-heat starting at 40 degrees and anything colder if you want to minimize wear on your bearings, cam and cylinders. The best preheat includes an insulated engine cover, which helps get the entire engine compartment warm, including accessories, and for C models the battery.
kellym Posted October 3, 2013 Report Posted October 3, 2013 I cannot advise you on the legality of witerizing your oil cooler with tape. Opinions differ on that subject. I'm more concerned about oil temps. If I get ramp checked, and the bureaucrat has an issue with it, I'll deal with it then... AFAIK, there is no winterization kit for my plane. Even if there is, the Al tape is an elegant and inexpensive solution... Kelly may be able to provide regulatory guidance! I agree with using the aluminum tape. Just limit what is covered to about 50% of total area. I also agree with multi-grade oil for cold weather. Not too many Feds are going to venture out on ramp in freezing temps. My plane in Fairbanks lived within view of FSDO windows. I have not been ramp checked in 40 yrs of flying.......oh, oh, here comes one now...
Jsavage3 Posted November 4, 2013 Report Posted November 4, 2013 I live in Ohio and I fly all winter long. When I drive to the airport with the family for a trip, I do not like sitting around waiting for an hour while the Tanis engine heater heats things up. Now what? Simple, cost effective & minimal hassle is required...so... I use a 100W lightbulb (Bayco 150-Watt Incandescent Portable Work Light and Item #: 203213 | Model #: FL-300NPDQ12 at Lowe's for $7.95) with a 50-foot extension cord and a ThermoCube TC-3 (electric ON at 35 degrees F and OFF at or above 45 degrees). I run the bulb up the left cowl flap and secure it with the clamp such that the bulb itself doesn't touch anything. After that, I use a rolled up towel to plug both cowl flaps...oil door closed...cowling inlet plugs in place as well. After that, just plug it in. My entire engine compartment never gets below 35 degrees...on a frosty morning, EVERYTHING inside the cowl feels warm-n-cozy to my cold hand... So, when I arrive on that cold morning, I first turn on my heater (Lasko Utility Ceramic Compact Personal Electric Space Heater Item #: 5445 | Model #: 675919 at Lowe's for $50) with 20-ft long, 6-inch diameter flexible & heat-resistant duct (hose) and run that into the baggage compartment door to heat the cabin. While that's preheating the cabin, I usually pre-flight the bird (which includes unplug the cowl flap openings, turn off the engine compartment bulb and remove it) while my family sits in the warm car and watches... Arrive-to-airport to taxiing is usually 15 min tops (does depend on how many bags I have to load) with minimal hassle, family stays warm (and HAPPY which translates to they want to go flying with me again sometime), we climb into the bird without coats on and crank up without cold issues. If at the destination I'm going to be sitting out somewhere in the cold all day, I take a 100-ft extension cord, my clamp-lamp (spare bulb doesn't weigh much either) and a couple of rolled towels with me... I use Aeroshell 15W50 with Camguard year around.
kmyfm20s Posted November 4, 2013 Report Posted November 4, 2013 After just finishing an owner assist top overhaul I would think that cold starts would be the most traumatic on the valve train. After learning how the hydraulic lifters actually work I can't imagine the stresses put on the cam lobes and the push rods until the oil viscosity decreased. Basically you would have some lifter compressed leaving slack slapping around, not opening the valves all the way, and some fully extended putting some serious pressure on the came and rockers. It make since why people hear clicking and ruff running engines until they warm up. I put in a Reiff heater, in San Diego we get cold below 70df
aaronk25 Posted November 4, 2013 Report Posted November 4, 2013 After just finishing an owner assist top overhaul I would think that cold starts would be the most traumatic on the valve train. After learning how the hydraulic lifters actually work I can't imagine the stresses put on the cam lobes and the push rods until the oil viscosity decreased. Basically you would have some lifter compressed leaving slack slapping around, not opening the valves all the way, and some fully extended putting some serious pressure on the came and rockers. It make since why people hear clicking and ruff running engines until they warm up. I put in a Reiff heater, in San Diego we get cold below 70df Good Advice there...... I also have a Reiff (50w cylinder bands as the 100w, I originally had installed kept burning out) and leave it plugged in all the time. With the bruce custom cowl plugs, the air in the cowl is excess of 100degrees, and my oil analysis results come back with zero moisture. I also don't think that a 3 hour preheat is long enough when the engine is sitting at 10 degrees. Mine stays plugged in all the time, and if necessary 12 hours ahead by generator power. Engines are expensive. 100w light bulbs won't cut it in MN.
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