winter preheat?

[Formerly Steve Wilkinson]

It's the first 14-degree morning here in the Hudson River Valley, and it makes me wonder: does anybody do anything imaginative about preheating their 911 engines before making a cold start? Cold starts kill me, particularly on air-cooled engines, and with light airplanes, we make all sorts of efforts to preheat them at night before a winter-morning start. It's a little easier with an airplane, since the engine sits well off the ground, but some pilots do things as simple as suspending a lighted 100-watt bulb inside the engine compartment and throwing a blanket over the nacelle.

There are also flexible pads with heating elements inside them that you epoxy to the wet sump of a Lycoming or Continental engine. I used to have one that I'd plug into a timer that set it to go on at four in the morning, and when I got to the hangar at nine, even the cylinder cooling fins would be temperate to the touch--not warm, but certainly not icy-cold either. And the crankcase and oil _would_ be warm. The pads cost about $150, and you could easily slap one on the side of the oil tank and have a thermostat that prevents them from heating past a certain point.

Anybody have any brighter ideas that they use? Heated garages don't count; I don't even _have_ a garage, out here in the country...

[Paulporsche]

In bookstores soon, the next 2 installments in the Gold Plated Series: "The Gold Plated Preheat Blanket" and "The Gold Plated Garage"!

Seriously, here in the Great White North, especially out in the west, people do exactly what you describe. There temps reach -40 on a regular basis, which is the same for C and F. I've never heard of anyone doing it on their 911, but that's probably because they just don't want to drive the cars then. I can't see how it could do anything but good, however.

BTW I have your book and enjoyed it.

[cnavarro]

I think you have the right idea to preheat the oil like with av engines. I know that I had a heating element for old type one engines that bolted onto the sump plate - kinda dangerous looking thing if you ask me. That's the main reason I switched to a 0w40, since I've been driving the 911 every day here (and it's cold too - 14.7F according to the outside thermo). As with any car, I try to keep the revs around 3000 rpm (kind of like what you had to do with the roller bearing 4-cam engines until warm) and don't put any appreciable load on the engine until the oil temp gauge starts to register. I'll tell you one thing, the 911 starts easier than some of the other new cars I have owned that take 0w20 or 5w20 fills.

I can cheat if I want to - the 911 is in the garage and I do have a torpedo heater in there that will take it from 15 to a balmy 65 in no time, but I highly doubt that would even raise the ambient engine / oil temperature unless I hold that temp all day.

[Formerly Steve Wilkinson]

The aircraft sump heaters are safe. They have to be: they're STCed. You can't put anything on an aircraft engine (unless it's registered as an experimental) that hasn't been fully tested and FAA-approved. If an airplane anywhere in the world ever burned because one of the heaters failed, every airplane in the U. S. that had one would probably be grounded until removal...

[DaddyGlenn]

I had on of these I used on an old Toyota 4x4 when I lived in Colorado. Seemed to make a bit of a difference.

http://cgi.ebay.com/ebaymotors/Kats-Oil-Dipstick-Heater-23-element-CLEARANCE-SALE_W0QQcmdZViewItemQQcategoryZ46098QQihZ020QQite mZ300057770207QQrdZ1QQsspagenameZWDVW

[rooked 930]

A couple of 75W halogen lamps left overnight somewhat works for me. I say somewhat, as I park inside an unintentionally heated garage (attached to the house, but no heater vents) - so temps aren't that bad anyway. Maybe a little bit of superstition about turbo health.

rob
79 930

[cgarr]

These work nice, bond it right to your case. If you dont want it on all night just use a timer..

http://www.aircraftspruce.com/catalog/eppages/ezHeater.php

[Formerly Steve Wilkinson]

Yup, exactly what I had on my last Lycoming.

[Porsche virgin]

Please excuse the stupidity, but why would a cold start on an air-cooled engine be any worse than a water-cooled one?

I don't drive my car very much during the winter (damn salt), but I don't put it away, either.

[cgarr]

Dissimilar metals with radically different expansion coefficients, thats just a guess

[Formerly Steve Wilkinson]

Air-cooled engines also typically use substantially higher-viscosity oils (though the adaptability of synthetics helps), which stay syrupy and slow-moving a lot longer. The new Lexus LS 460, for example, uses special zero-weight oil (helps fuel economy slightly) because it has such fine tolerances and balanced, perfect surfaces. I'd feel far better starting and running one of them at minus 10 than a 911 with three gallons of 40- or 50-weight aboard.

[DarrylD]

I just slide a 500-watt halogen work light under the engine overnight. I get about a 100º F reading when I shoot my IR thermometer at the sump plate in the morning , so that's plenty pre-heated!

I can't believe how much happier the CIS is on cold days when the engine is already warm, no popping and snorting, just a nice even idle right off the bat.

I use this same halogen worklight heater technique on the Volvo Penta Turbo Diesel in the bilge of my boat in the winter and the starter hardly has to work before it fires up.

[Porsche virgin]

Originally posted by Formerly Steve Wilkinson
Air-cooled engines also typically use substantially higher-viscosity oils (though the adaptability of synthetics helps), which stay syrupy and slow-moving a lot longer. The new Lexus LS 460, for example, uses special zero-weight oil (helps fuel economy slightly) because it has such fine tolerances and balanced, perfect surfaces. I'd feel far better starting and running one of them at minus 10 than a 911 with three gallons of 40- or 50-weight aboard.

Gotcha. I think I use 20w50 in my car. Can you use a lighter-weight oil in the winter, provided you change back to the heavier weight once spring hits?

[pieterk]

Last weekend I propped a small high voltage heater/fan on the edge of the bumper/chassis with the decklid resting on top of it (it's pretty small) and pointed the heater into the engine fan for an hour before starting. Morning temps were in the upper 20s and my MFI motor gets cranky when it gets cold(er).

An hour later, everything in the engine bay was temperate to the touch. It worked nicely.

[RoninLB]

there was a pretty extensive thread on this subject a couple of years ago. I posted a lot of info about very cold starting air cooled engines. A nice aircraft heater is around $500.

fwiw... I went for a ride around 2-3am today. Ambient was around 20F. My CHTs never got warmer than around 190-210F. My poor spark plugs. I usually run around 250-275F and that's what the carbs are tuned for.

[Formerly Steve Wilkinson]

Porsche virgin, for your car 20W-50 is good down to around +15F. 10W-40 or 10W-50 is specified if it goes down to about -5F, which is probably about as cold as you and I will see here in lower New York, 10W-30 for down to -15F or so.

[MRM]

The light idea is kind of dangerous because it is a fire hazard.

A better idea is a plug in block heaters or one of those plug in heaters that clip onto the oil pan or are inserted in place of the dipstick. Should be available at finer Shopkos, Wall Marts and Targets.

[livi]

I have a warm garage, so my engine will not be that cold. But still..how much less wear would the engine suffer over time if it was heated well above warm garage temps ?

Say I have 15 degree Celsius in the garage during winter and I could pre heat the engine to 45 for example. Would that make a difference in the long run ?

Here in Sweden we have had special engine pre heaters for ages. I have never tried them, maybe I should. Or is it over kill since I have a warm garage ?

[304065]

Steve, I used to aim my torpedo heater at the car's engine. The flume of heat it generates shoots out for a couple feet and then rises-- perfect for heating the engine in a no-contact way.

Worked pretty good for the Citabria's lycoming, too. After about 10 minutes the exhaust stack was hot to the touch. I had a pad heater on the oil sump also-- seems to me you could put one on the side of the oil tank in a 911 with a "remove before flight" banner on the plug, of course!

[Formerly Steve Wilkinson]

I don't think MRM's block heater idea will work. As far as I know, those things are intended to heat the coolant in a liquid-cooled block, and they're usually inserted in place of a freeze plug. We don't have freeze plugs. Dunno about the dipstick heater, since we have such wierd dipsticks...