FloridaMan Posted November 29, 2012 Author Report Share Posted November 29, 2012 I wonder about the impact to hundreds of millions car engines starting in sub freezing weather every day. Look at car engines with cast iron or nickel-steel alloy blocks and aluminum heads and you'll see a very high incidence of cracked cylinder heads and blown head gaskets. Add in turbochargers and you'll see the failure rate go up significantly. Google : "cracked cylinder head dissimilar metals" Quote Link to comment Share on other sites More sharing options...
FloridaMan Posted November 29, 2012 Author Report Share Posted November 29, 2012 I use this for preheat. I preheat when below 30F. I do not start engine until the dipstick drips. Looks like your plane may have a drug problem. 1 Quote Link to comment Share on other sites More sharing options...
RJBrown Posted November 29, 2012 Report Share Posted November 29, 2012 Posted Yesterday, 02:00 AM mooniac58, on 27 November 2012 - 08:37 PM, said: I did a lot of research on this before and my understanding is that the general misconception is that the concern is oil being too cold, but with modern synthetic muti-grade oils this is not really the case - however the real concern is the different expansion/contraction rates of the steel and aluminum parts in our engines. "I would disagree with this, any type of oil is going to get viscous when it gets cold. Pumping that sludge through the engine, oil cooler, prop governor, etc. isn't a good thing. I agree with Piloto which is unless the oil is loose on the dipstick you probably aren't doing your engine a lot of favors by trying to start it". This opinion incorrect. The original post is correct. The issue IS dissimilar expansion rate of different metals. Thinned/warmed oil is an indication that the engine is warm but it is not the point of the warming. Just a good byproduct of it. If it were just oil viscosity different oil would fix it. It is a metals fit/expansion issue. A good preheater has multiple heat points to evenly heat the block/cylinders/pistons. A single point oil heater is not used because it is not why we pre heat. In a car preheating the oil IS adequate because of the differences in how the engines are made. Quote Link to comment Share on other sites More sharing options...
jrwilson Posted November 30, 2012 Report Share Posted November 30, 2012 where I am in California, it doesn't get super cold too often. Besides, I have a hangar. If I'm leaving early morning and it is below 40, I do preheat. I made a preheater which works pretty well; it is a hair dryer with a flexible hose attached. Put it in the cowling access door and put the hose near the bottom. The whole cowling warms up pretty quick. I also use a chicken brooding light if it is really cold, stick that up the cowl flap. It pumps out a surprising amount of heat. Close the cowl flaps, put the cowling plugs in and in about 15 minutes it is pretty toasty. Quote Link to comment Share on other sites More sharing options...
jetdriven Posted November 30, 2012 Report Share Posted November 30, 2012 Posted Yesterday, 02:00 AM mooniac58, on 27 November 2012 - 08:37 PM, said: I did a lot of research on this before and my understanding is that the general misconception is that the concern is oil being too cold, but with modern synthetic muti-grade oils this is not really the case - however the real concern is the different expansion/contraction rates of the steel and aluminum parts in our engines. "I would disagree with this, any type of oil is going to get viscous when it gets cold. Pumping that sludge through the engine, oil cooler, prop governor, etc. isn't a good thing. I agree with Piloto which is unless the oil is loose on the dipstick you probably aren't doing your engine a lot of favors by trying to start it". This opinion incorrect. The original post is correct. The issue IS dissimilar expansion rate of different metals. Thinned/warmed oil is an indication that the engine is warm but it is not the point of the warming. Just a good byproduct of it. If it were just oil viscosity different oil would fix it. It is a metals fit/expansion issue. A good preheater has multiple heat points to evenly heat the block/cylinders/pistons. A single point oil heater is not used because it is not why we pre heat. In a car preheating the oil IS adequate because of the differences in how the engines are made. I totally agree. Also, as aviatoreb pointed out, as the engine gets colder, the case shrinks around the cam and crank. At some temperature, the aluminum case actually shrinks so much the main bearing and cam clearance is essentially zero. Add to this, some folks think that straight weight oil lubricates better. There may be some truth to that, but at 20 degrees F, that 50-weight oil is essentially solid. The oil pump cavitates and you have air mixed with the oil going to your engine bearings. Lycoming says do not take off if you have fluctuating oil pressure. The rest of the story is that is oil pump cavitation. That said I have seen very few main or rod bearing wear failures in these engines, but many cam/lifter failures and cylinder scuffing issues. The expanson rate of steel is half that of aluminum. Starting up a cold engine has the aluminum pistons rapidly expanding inside a slow-to-expand steel cylinder barrel. Plus that cold, thick, ropey oil doesnt sling well and get between the cam and lifters. Multigrade oil mitigates the oil pressure and slinging issues, but nothing short of heat will convince your pistons not to scuff. Quote Link to comment Share on other sites More sharing options...
RJBrown Posted November 30, 2012 Report Share Posted November 30, 2012 where I am in California, it doesn't get super cold too often. Besides, I have a hangar. If I'm leaving early morning and it is below 40, I do preheat. I made a preheater which works pretty well; it is a hair dryer with a flexible hose attached. Put it in the cowling access door and put the hose near the bottom. The whole cowling warms up pretty quick. I also use a chicken brooding light if it is really cold, stick that up the cowl flap. It pumps out a surprising amount of heat. Close the cowl flaps, put the cowling plugs in and in about 15 minutes it is pretty toasty. This may make you feel better when it is between 30 and 40 degrees but it is a waste of time. Purely a placebo. When it gets cold, and your record cold for today of +29 does not count, you need a lot more heat and for a much longer time. You are blowing less than 1000 BTUs where a proper heater is over 100,000 BTUs. When it is COLD you need a real heater. A little hair dryer is not a engine pre heater. The average low in El Dorado hills in the coldest month is 38. Most record lows are in the 20s. In a hanger you will never be cold enough to preheat. A plane parket outside in below 0 temperature will need close to an hour of heat from a 100,000 BTU heater to get up to you record cold. If you need heat this wont help. If this helped you didn't need it. Pre heating a cold engine is a serious thing, Don't trivialize it with a hair dryer. Quote Link to comment Share on other sites More sharing options...
danb35 Posted November 30, 2012 Report Share Posted November 30, 2012 You are blowing less than 1000 BTUs where a proper heater is over 100,000 BTUs. This really isn't correct, as time is a factor as well. The standard Reiff system for a 4-cyl engine is 300 watts, which works out to about 1000 BTU/hr; by all accounts it works quite well. It doesn't, of course, heat the engine in 10 minutes, nor does it claim to. If you really need to preheat an engine in 10 minutes, you'll need something propane-powered, but not everyone needs the speed heat. FWIW, most hair dryers I've seen are rated at 1500W, which works out to about 5000 BTU/hr. Quote Link to comment Share on other sites More sharing options...
RJBrown Posted November 30, 2012 Report Share Posted November 30, 2012 Read my previous post. I use a plug in heater for a minimum of 8 hours. This is about blowing hot air in the LOWER cowl flap, not the oil door. The recommendation from Lycoming starts lower than what I do. Any time it is below freezing I recommend pre heat. When I need to go somewhere early and expect cold I lug a generator out to the plane the night before and plug in the Tanis. If it feels cold on the head I will also use the propane heater. Some nights when it gets below 0 the engine still feels cold even with the Tanis. To fully heat a cold (o degree) engine with hot air takes 100,000 BTU propane heat at least 30 minutes, preferably more. The point is: It never really does get cold there in California. A hair dryer is a waste of time. These type of recommendations are at best misleading. But you are right it is 1/20 the heat needed not the 1/100 I stated. With a blanket and 8 hours a hair drier could work in an emergency. I doubt a hair drier is rated for 8 hours of continuous use. Find a real solution. 15 minutes from a hair drier is not a solution. Spending too much money is not the solution either. There are ways to spend $1000 to have preheat. I bought a heater and a vent pipe reducer from Home Depot. I power it from my car battery with a small inverter. I use a 5 foot section of scat tube to run it in the lower cowl. For under $150 I have a heater that I have used for over 15 years. 1 Quote Link to comment Share on other sites More sharing options...
bnicolette Posted December 23, 2012 Report Share Posted December 23, 2012 I am pulling the trigger on ordering and installing a Reiff preheat system this winter season. I was using a torpedo heater with a homemade ducting contraption, but those little 5 gallon propane tanks don't last all that long and why use my utilities when electric comes with my hangar? Anyhow, I am planning on leaving the Reiff plugged in all the time. From what i've read thus far, I can't find anything that states this is a problem. If somebody knows different, could you please let me know. If need be, I would buy Phillips remote cell switch, but I'm not sure it's needed for me. Thanks for any help..............again. Quote Link to comment Share on other sites More sharing options...
carusoam Posted December 24, 2012 Report Share Posted December 24, 2012 Brett, How hot do the local spots near the heaters get? Localized heating of the oil being the concern. Best regards, -a- Quote Link to comment Share on other sites More sharing options...
bnicolette Posted December 24, 2012 Report Share Posted December 24, 2012 Brett, How hot do the local spots near the heaters get? Localized heating of the oil being the concern. Best regards, -a- Anthony I'm not sure how hot that pad would get. I am going for the standard system which includes a 100w pad for the sump. Do you think that would be an issue with leaving it powered up all the time? B Quote Link to comment Share on other sites More sharing options...
Marauder Posted December 24, 2012 Report Share Posted December 24, 2012 I remember the old tale of how pre-heaters were the culprit. I think the culprit was actually the cycling of these pre-heaters. I have a vault and use a heating rod to keep the temperature a few degrees warmer in the vault than ambient air in both summer and winter. This prevents condensation inside of the vault on the contents. I believe the same theory would hold true for airplanes if you leave it on all the time -- winter AND summer. Rust is caused by the moisture reacting with the metal (by the way Mike Busch has a webinar in this topic). I would love to see a more definitive answer on this as well. As a side comment, I think there are several topics here. One being how best to pre-heat an airplane and the other if the pre-heater can cause rust. I can tell you from personal experience, when it is really cold, there is no moisture. It is all frozen. When you shut down in those kind of temperatures, any moisture freezes, including anything inside e engine. Using a pre-heater, especially if cycling, may introduce moisture by unfreezing it. The value of pre-heating is to prevent that wear that happens for a few minutes until the engine begins to warm. And I believe there are a number of ways to do that. Quote Link to comment Share on other sites More sharing options...
carusoam Posted December 25, 2012 Report Share Posted December 25, 2012 Many variables... O2 and oxygen aided by moisture... Oil running off surfaces aided by heat and gravity... Brett, I think the concern for the 100w heater is the local temperature getting over 400 degrees breaking down the oil would be serious if it gets that hot. I don't think it does, but I would want to know, before leaving it on. I have a Reiff on my IO550, haven't used it in three years. No electricity near my bird. I'm going to try again in the new year. Best regards, -a- Quote Link to comment Share on other sites More sharing options...
carusoam Posted December 25, 2012 Report Share Posted December 25, 2012 For Xmas, I'd like electricity and one of Phillip's devices... Best regards, -a- Quote Link to comment Share on other sites More sharing options...
Alan Fox Posted December 25, 2012 Report Share Posted December 25, 2012 How many cars use 20W-50 oil any more? Much less straight 50 weight? Most specify 5W-something, and many are now calling for 0W-. Also, most auto engines still have cast iron blocks, which will expand and contract at a rate much closer to the crankshafts. Most (over 90%) of auto engines have aluminum blocks and aluminum heads.....the reason they run 0 and 5 weight oils is because of windage affecting fuel economy....(windage is the friction of the oil against the bearing surfaces , and the wieght of the oil sticking to rotating components) The only reason head gaskets fail is because of electrolysis from not changing the coolant , or warpage from severe overheating....They don't fail from differential thermal expansion ...... 1 Quote Link to comment Share on other sites More sharing options...
M016576 Posted December 25, 2012 Report Share Posted December 25, 2012 Tanis preheat below 40F for at least 2hrs. Done. Quote Link to comment Share on other sites More sharing options...
jnisley Posted December 26, 2012 Report Share Posted December 26, 2012 We use the SAFE-HEET Variable Temperature Controller/700 Series SAFE-HEET Engine Pre-heater set to keep oil above 45 degrees, then turn it up during preflight. Monthly electric bill increases $10-20 depending on weather. Hard to find a perfect solution in an imperfect world. Quote Link to comment Share on other sites More sharing options...
kgbpost Posted December 26, 2012 Report Share Posted December 26, 2012 I have the reiff XP system with sump pads installed on both of my airplanes in conjunction with pilotportraits remote cell phone activated controllers. I generally "call my airplane" the night before and when I arrive and start the engine the oil temp immediately indicates 100F plus, the case and cylinders are warm to the touch with no cowl plugs or blankets used. I am very happy with this setup. I used to race open wheel cars called Midgets. The powerplant was a 4-cylinder Ford with aluminum block and heads that we turned as high as 10,000+rpm. The engine builder, Esslinger Engineering, actually hones the blocks in a heated oil tank to account for the distortion of the block at operating temp vs. ambient. if you set the valve lash on the cold engine and then heat it to operating temp, the lash will tighten by .003 to .006 in. That is huge since the recommended lash is .008-.010. We would always preheat and prime the oil pump before starting it per Esslinger's recommendations. I therefore always preheat my airplane engines below 40F. In the event I called my airplane the night before and then subsequently have to scrub due to weather, I will at the least pull the airplane out and due a ground run to circulate the oil in case of any condensation in the case cause by preheating. maybe I'm a little overboard, but that's my SOP. Quote Link to comment Share on other sites More sharing options...
bnicolette Posted December 29, 2012 Report Share Posted December 29, 2012 My Reiff system should be here on Tuesday. Â Is there anything special about the installation or is it pretty straight forward? Â I only got the standard system so it will have just the one oil sump pad. Quote Link to comment Share on other sites More sharing options...
Marauder Posted December 29, 2012 Report Share Posted December 29, 2012 My Reiff system should be here on Tuesday. Is there anything special about the installation or is it pretty straight forward? I only got the standard system so it will have just the one oil sump pad. Post some pictures please. I have been a torpedo kind of guy for years. Would like to know how your installation goes. Quote Link to comment Share on other sites More sharing options...
bnicolette Posted December 29, 2012 Report Share Posted December 29, 2012 Post some pictures please. I have been a torpedo kind of guy for years. Would like to know how your installation goes. Yep........I am also a torpedo kind of guy.............but I can't wait to quit this process. Â I mean it works great but really takes a long time to get the baby ready to go out in the cold wx. I will definitely take some pics/video of the installation! Â http://www.youtube.com/watch?v=x0YhEodKBE8 Â Quote Link to comment Share on other sites More sharing options...
Marauder Posted December 29, 2012 Report Share Posted December 29, 2012 That is too funny! I have an orange torpedo, otherwise everything else is the same including the ceramic heater! Quote Link to comment Share on other sites More sharing options...
kgbpost Posted December 30, 2012 Report Share Posted December 30, 2012 My Reiff system should be here on Tuesday. Â Is there anything special about the installation or is it pretty straight forward? Â I only got the standard system so it will have just the one oil sump pad. No it's very straight forward. The wiring harness runs along the top of the crankcase except for the sump pad wire. The main thing is to follow the instructions carefully regarding the epoxying the sump pad so it remains attached. This time of the year renting a space in a heated hanger for a night to install it and let the epoxy cure properly might be the trick way to go. Brian Quote Link to comment Share on other sites More sharing options...
RJBrown Posted January 2, 2013 Report Share Posted January 2, 2013 This is what I use for spur of the moment preheats. Tanis over night when possible. This afternoon My son and I were bored so we ran out to the airport for a quick flight. My son is 13 and has flown straight and level before but today he taxied with help and a lesson on the brakes. IÂ took it off and landed but he flew around for about 45 min. When we got down he said "That was fun" Quote Link to comment Share on other sites More sharing options...
bnicolette Posted January 2, 2013 Report Share Posted January 2, 2013 This is what I use for spur of the moment preheats. Tanis over night when possible. This afternoon My son and I were bored so we ran out to the airport for a quick flight. My son is 13 and has flown straight and level before but today he taxied with help and a lesson on the brakes. IÂ took it off and landed but he flew around for about 45 min. When we got down he said "That was fun" Cain't wait till my little guys want or ask me to take them flying. Â They love to fly if we are going somewhere, but to go for a joy ride is just not up their alley yet. I like how you have the ducting attached to the torpedo. Â I was afraid of flames actually traveling through there, but I guess they don't? Quote Link to comment Share on other sites More sharing options...
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