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#1
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posted to uk.rec.sailing,rec.boats.cruising
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![]() Not enough can be said for NOT squirting explosives into the intake of a small, LIGHTLY MADE diesel engine. DON'T DO THIS! Notice it says not to do this right in the manual! I worked in a Detroit shop when I was a kid. Mostly fisking boats and logging equipment/trucks. Got to do basic rebuilds on 53, 71, 92 series. The head mechanic took me asides and showed me two 6-71 engines in for a rebuild. One operator used ether regularly caus it was cheeper than a new charging system and new batteries. The other operator never used the stuff. It was stunning to comapre the two during de assymble! The heat gun is a great idea if you have a power source to run it from. Let's avoid lighting fires in the engine compartment fumes of fuel and battery hydrogen to crank them, ok? Thanks! Concure............................ " ...flames on boat.......bad." Suggest using the spay can to help start the grill you moved to the dock. Babbit Bob |
#2
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posted to uk.rec.sailing,rec.boats.cruising
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In article , Larry
wrote: Derek Moody wrote in news:ant051635965BxcK@half- baked-idea.co.uk: A cautious squirt of ether can help too but mustn't be overdone. Not enough can be said for NOT squirting explosives into the intake of a small, LIGHTLY MADE diesel engine. DON'T DO THIS! Notice it says not to do this right in the manual! We appear to be talking about engines big enough to require starter motors, I agree that tiny one or two cylinder jobs wouldn't like it (I said a cautious squirt and into a fast spinning engine but you snipped that bit.) With a really small engine hand cranking to help the starter is a much better idea. Diesels run on the heat of compression. There are two ways of artificially creating this SAFELY when they are cold.....preheat the cylinders, preferably with glow plugs...or preheat the air, preferably with an air pre-heater in the intake. HEATING THE FUEL DOES NOT MAKE And if you have either fitted you don't need other heating... The heat gun is a great idea if you have a power source to run it from. As always there is a pay off between heated air (lower mass of air per inspired volume) and heat of compression. The engine block in winter is a massive lump of over-chilled heatsink, anything to get a little heat in there will help. The usual reason why they won't start is THE COMPRESSION IS TOO LOW or THE ENGINE DOESN'T SPIN FAST ENOUGH....both of which, of course, require If you have a small heater than it might be better used to warm your batteries to make sure you're getting maximum starter speed. Elsewhere in this thread are comments about winterising/waxing up of fuel. While this is all true for diesels in general I doubt it makes any noticeable difference to vessels afloat in British waters. The tank, engine compartment, and fuel lines are almost always at least partially below the water line and so rarely get much below harbour-water temperature which in turn will usually be above zero even in sal****er. I have never tried this but it occurs to me that a couple of kettles' full of hot water poured slowly over the block (might as well add detergent and break out a scrubbing brush) would transfer heat as well as anything. Cheerio, -- Fishing: http://www.fishing.casterbridge.net/ Writing: http://www.author.casterbridge.net/derek-moody/ uk.rec.fishing.game Badge Page: http://www.fishing.casterbridge.net/urfg/ |
#3
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posted to uk.rec.sailing,rec.boats.cruising
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Derek Moody wrote in
: Not enough can be said for NOT squirting explosives into the intake of a small, LIGHTLY MADE diesel engine. DON'T DO THIS! Notice it says not to do this right in the manual! We appear to be talking about engines big enough to require starter motors, I agree that tiny one or two cylinder jobs wouldn't like it (I said a cautious squirt and into a fast spinning engine but you snipped that bit.) With a really small engine hand cranking to help the starter is a much better idea. Read someone else's reply to my paragraph about GM 6-71 and 8V-92 large diesels being overhauled. Ether starting is very hard on ANY diesel. Larry -- Have a little fun in the checkout line.... Ask the nearest American, "Did you see the ICE agents chasing those Mexicans out the back door?" ....Shortens that checkout line right up...(c; |
#4
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posted to uk.rec.sailing,rec.boats.cruising
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![]() "Cerumen" wrote in message ... "Ted Bell" wrote in message ... When it's very cold I have a hard time cranking my diesel. I was wondering if I put Tilley wicks saturated in meths around the injectors and lit them if it would warm up the injectors enough to vaporize the fuel better. Anybody ever try it? No but I have warmed a reluctant deisel with a blow lamp before now, heat inlet manifold and then crank. Another tip is to cover, if you can, the inlet port which can make the engine spin a lot faster, remove the blockage and inertia helps to start it. -- Chris, West Cork, Ireland. If I've read it right a diesel compresses the air to a very great extent. The compression heats the air so much that fuel self-ignites when injected into the hot air. Even if it's very cold it's my understanding the compressed air is still hot enough to ignite the fuel. So it seems to me if the fuel doesn't ignite maybe it's because it's so cold and thick that the injectors don't spray it in properly. Maybe just dribbles of larger droplets that are reluctant to burn. So heating the injectors seems like it would take care of that problem. Sort of the same principle that a pressure diesel stove uses to pre-heat the fuel. Meths don't burn all that hot so although it might blacken the paint I can't see where it would damage the injector. I think I'll give it a go. .. . Thanks to all who responded. I'm Ted Bell! |
#5
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posted to uk.rec.sailing,rec.boats.cruising
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Ted Bell wrote:
If I've read it right a diesel compresses the air to a very great extent. The compression heats the air so much that fuel self-ignites when injected into the hot air. Even if it's very cold it's my understanding the compressed air is still hot enough to ignite the fuel. So it seems to me if the fuel doesn't ignite maybe it's because it's so cold and thick that the injectors don't spray it in properly. It is more common, particularly on engines well past their youth, that compression is not as good as it should be. The result is that the compressed air doesn't get hot enough quickly enough at low revs in a cold engine block. This seems a likelier scenario than the fuel being too viscous at low temperature to disperse properly. Maybe just dribbles of larger droplets that are reluctant to burn. So heating the injectors seems like it would take care of that problem. Sort of the same principle that a pressure diesel stove uses to pre-heat the fuel. Meths don't burn all that hot so although it might blacken the paint I can't see where it would damage the injector. I think I'll give it a go. Many engines are fitted with electric glow-plug preheaters. I don't think they heat the injectors, but part of the combustion chamber. On some engines, electric heater coils are located within the air intake. This is an easy option to retro-fit (unlike glowplugs which really need to be designed in from the start), and Bukh, for instance, offer this option and I can vouch for how well it works. They basically preheat the air, so that it's already warmer before it gets heated by being compressed. The result is that the compression heats the air up to an even higher temperature, making it more likely that the engine will fire sooner. I would recommend that if you want to have a go, it would be a better idea to heat up the air intake than the injectors. |
#6
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posted to uk.rec.sailing,rec.boats.cruising
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Ronald Raygun wrote in
. uk: Many engines are fitted with electric glow-plug preheaters. I don't think they heat the injectors, but part of the combustion chamber. Glow plugs are situated in the path of the spray pattern of the injector, usually in a pre-combustion chamber which not only makes the engine much easier to start, but much quieter to run. http://www.kenrockwell.com/190d/images/lvp.gif Here's the precombustion chamber of a Mercedes Benz 190D diesel. The glowplug is the gold pin right under the spray head. It heats red hot just before the engine starts, causing the fuel to explode reliably as soon as it is injected, by the injector directly above it. It continues to glow, as does the grey resonator under it while the engine is running, not by the electrical current, but by the last time the fuel exploded. The explosion happens in the precombustion chamber and an immense pressure pushes the explosion into the air charge down in the cylinder through those tiny holes, maybe 1/8" diameter, in a radial pattern on top of the piston to balance the pressure on the piston top. After 25 years of constant use, my '73 220D sedan's little 57hp diesel piston had 5 little tracks across the top of the piston showing where the explosion went by it at TDC on ever other stroke. I couldn't get over how small these holes are and how clean they stayed all those years when we overhauled it at about 250,000 miles. It really only needed new rings. Notice in MB cars, the whole chamber screws out so it can be easily replaced if it cracks under the pressure. Smart, very smart. All this is done to reduce the compression necessary to start it cold and run it QUIETLY in a nice car. It ran fine on vegetable oil going to breakfast with my old friends, this very morning...(c; Larry -- Have a little fun in the checkout line.... Ask the nearest American, "Did you see the ICE agents chasing those Mexicans out the back door?" ....Shortens that checkout line right up...(c; |
#7
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posted to uk.rec.sailing,rec.boats.cruising
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"Ted Bell" wrote in news:eshhk2$mji$1
@aioe.org: Even if it's very cold it's my understanding the compressed air is still hot enough to ignite the fuel. As long as there is proper compression, you're absolutely right. Test the compression on a COLD engine, not hot, to see if it has enough pressure on ALL cylinders. So it seems to me if the fuel doesn't ignite maybe it's because it's so cold and thick that the injectors don't spray it in properly. Maybe just dribbles of larger droplets that are reluctant to burn. Well, this sounds good but is very hard to achieve. If diesel fuel is NOT properly "winterized" by mixing it with light elements, WAX CRYSTALS form in the diesel fuel making it impossible to pump. It doesn't "thicken", it turns to a SOLID! You can heat the whole fuel system and keep it from waxing up. In boats, the problem is the cheapskate sailors use so little fuel, they only buy it in SUMMER when it's not winterized, which costs the fuel companies extra money. Winter comes, the tanks are full of unwinterized diesel he "saved" by not burning it. It turns to wax in the cold and the engine won't crank as it has no fuel...the fuel system blocked by the wax until Spring. He's ****ed and needs someone to blame. What he SHOULD have done was to burn the tank dry before it got too cold and refilled it in the Fall with WINTERIZED diesel fuel, which doesn't turn to jelly in the cold. Cheapskate didn't. Hell, he never fills his tanks and has water ingestion problems, too, storing it 1/4 full. Oh, the WATER in the tanks he never fills ALSO causes fuel starvation as IT freezes in the tanks, filters, low points of the lines, etc....another problem easily fixed. So heating the injectors seems like it would take care of that problem. Sort of the same principle that a pressure diesel stove uses to pre-heat the fuel. Meths don't burn all that hot so although it might blacken the paint I can't see where it would damage the injector. I think I'll give it a go. No, because he can't pump solid fuel into where the heated pump is as it's waxed up in the lines. The cure is WINTERIZED DIESEL FUEL, available after a certain date in that area. His tanks have summer diesel fuel in them full of wax crystals....cloudy on cool days, solid on cold. Please don't light any open fires in the engine compartment with the battery fumes, ok? We don't need any MORE excitement on boat newsgroups than the usual groundings.... Larry -- Have a little fun in the checkout line.... Ask the nearest American, "Did you see the ICE agents chasing those Mexicans out the back door?" ....Shortens that checkout line right up...(c; |
#8
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posted to uk.rec.sailing,rec.boats.cruising
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On Mon, 5 Mar 2007 11:48:05 -0500, "Ted Bell"
wrote: If I've read it right a diesel compresses the air to a very great extent. The compression heats the air so much that fuel self-ignites when injected into the hot air. Even if it's very cold it's my understanding the compressed air is still hot enough to ignite the fuel. So it seems to me if the fuel doesn't ignite maybe it's because it's so cold and thick that the injectors don't spray it in properly. Maybe just dribbles of larger droplets that are reluctant to burn. So heating the injectors seems like it would take care of that problem. Sort of the same principle that a pressure diesel stove uses to pre-heat the fuel. Meths don't burn all that hot so although it might blacken the paint I can't see where it would damage the injector. I think I'll give it a go. . . Thanks to all who responded. I'm Ted Bell! I don't think heating the accessible parts of the injectors will do much good - the nozzle is deep inside the head, and the body of the injector passes through metal immersed in the cooling water, so very little heat will make it to the injector nozzle. -- Peter Bennett, VE7CEI Vancouver BC, Canada peterbb4 (at) interchange.ubc.ca new newsgroup users info : http://vancouver-webpages.com/nnq GPS and NMEA info: http://vancouver-webpages.com/peter Vancouver Power Squadron: http://vancouver.powersquadron.ca |
#9
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posted to uk.rec.sailing,rec.boats.cruising
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In article ,
"Ted Bell" wrote: When it's very cold I have a hard time cranking my diesel. I was wondering if I put Tilley wicks saturated in meths around the injectors and lit them if it would warm up the injectors enough to vaporize the fuel better. Anybody ever try it? I'm Ted Bell! You don't need to heat the FUEL, you need to heat the AIR...... Bruce in alaska -- add a 2 before @ |
#10
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posted to uk.rec.sailing,rec.boats.cruising
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![]() "Bruce in Alaska" wrote in message ... In article , "Ted Bell" wrote: When it's very cold I have a hard time cranking my diesel. I was wondering if I put Tilley wicks saturated in meths around the injectors and lit them if it would warm up the injectors enough to vaporize the fuel better. Anybody ever try it? I'm Ted Bell! You don't need to heat the FUEL, you need to heat the AIR...... It seems like that's the majority opinion. But no matter how hot the air it won't burn all by itself. You must have atomized fuel injected into the hot air. All the suggestions about pre-heating the air only make sense provided the fuel hasn't turned to wax from the extreme cold. It's quite difficult to inject wax, I would think. Wax doesn't burn until it turns into a liquid. This is evident when one lights a candle. Once the motor runs for a bit it heats the fuel quite nicely because of the way it re-circulates it through the system. But what's to keep fuel that might not be winterized properly from clogging up the works before it gets warmed up? Maybe the answer is a fuel tank heater and a stout lever on the fuel pump to pump the warm fuel round. I'm Ted Bell! |
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