NonMember Posted January 14, 2022 Report Share Posted January 14, 2022 2 minutes ago, daverclasper said: All the physics stuff way over my head. I guess battery's are a different thing, as apparently have more power when warmer?, and also spark plugs, apparently ignite fuel better if warmed?. Genuinely interested. You'll note I said "all metals" - a car battery has a lot of not-metal in it, specifically acid. It works by a chemical reaction of that acid with the lead, and most chemical reactions work better when warm. Similarly (well, vaguely similarly) a spark plug works by a cascade ionisation reaction (kind of on the boundary between chemical and physics), which requires a good supply of free electrons. These are released off the surface of the electrodes by vibrations that increase with temperature. A hot electrode has a much bigger supply of free electrons and thus generates a fatter spark. That's also why you connect the coil to supply a negative HV, as that makes the small, centre electrode (which is more thermally isolated and thus hotter) the one that needs to emit the electrons. 1 Link to comment Share on other sites More sharing options...
ahebron Posted January 15, 2022 Report Share Posted January 15, 2022 12 hours ago, Iain T said: No chain links but plenty of leather......and feather dusters! On another note where my car is I don't have power, has anyone used the butane soldering irons and which ones work! Iain I have owned and used several different gas soldering irons over the years. They have all started out great but time spent in the tool box even in the supplied container and they have all failed. I think the Dremel ones have lasted the best. Maybe it is me. Bought the wire and inline fuse to make my own headlight relay control, 2 x30m 30a cable and an in line weather proof fuse plus postage $NZ142. Car electrics is expensive! I am a mains sparky and have loads of cable but the wrong type. 1 Link to comment Share on other sites More sharing options...
Iain T Posted January 15, 2022 Report Share Posted January 15, 2022 4 hours ago, ahebron said: Bought the wire and inline fuse to make my own headlight relay control, 2 x30m 30a cable and an in line weather proof fuse plus postage $NZ142. Car electrics is expensive! That's about £70!? My £7 each albeit with far less cable is cheap. Why is it so expensive in NZ? Iain Link to comment Share on other sites More sharing options...
Peter Truman Posted January 15, 2022 Report Share Posted January 15, 2022 Everything is expensive in NZ, except fresh air & the ocean! I have a Dremel gas portable soldering iron, works OK but I found it a bug**r to refill. For wiring & instrumentation I use cheap 40watt irons last about 4 years then buy another cheapie around $20 to $30. The one I have now is adjustable cost $20, I strip and clean regularly and is lasting >4yrs, having said that I bet it fails tomorrow!. Link to comment Share on other sites More sharing options...
Iain T Posted January 15, 2022 Report Share Posted January 15, 2022 As I have no electric it's a Dremel butane! Thanks all, I'm hoping to enter the RBRR this year so I'll need good headlamps😳🥕 Link to comment Share on other sites More sharing options...
Iain T Posted January 15, 2022 Report Share Posted January 15, 2022 29 minutes ago, Peter Truman said: Everything is expensive in NZ, except fresh air & the ocean! I I thought it was you Australians not NZealanders that had a spat with China (where everything is made), hence price hikes? Link to comment Share on other sites More sharing options...
SpitFire6 Posted January 15, 2022 Report Share Posted January 15, 2022 Link to comment Share on other sites More sharing options...
Iain T Posted January 15, 2022 Report Share Posted January 15, 2022 Interesting so a 10% drop in voltage results in about 30% less lumen? Link to comment Share on other sites More sharing options...
ahebron Posted January 15, 2022 Report Share Posted January 15, 2022 7 hours ago, Iain T said: I thought it was you Australians not NZealanders that had a spat with China (where everything is made), hence price hikes? 5 million people living on the most isolated temperate land mass in the world in a country of similar size to the UK has it advantages and disadvantages. For soldering I use mains powered and currently have a solder station with adjustable temperature control for the iron and airgun which can do surface solder but I mainly use it for heatshrink. Made in China and replace when it goes bang. 2 Link to comment Share on other sites More sharing options...
dougbgt6 Posted January 15, 2022 Report Share Posted January 15, 2022 On 14/01/2022 at 18:24, daverclasper said: spark plugs, apparently ignite fuel better if warmed Don't diesels have plug warming? I had a Peugeot 406 which had a 15 second delay on start up to warm the plugs. Once you get below zero batteries loose capacity alarmingly. db Link to comment Share on other sites More sharing options...
NonMember Posted January 16, 2022 Report Share Posted January 16, 2022 9 hours ago, dougbgt6 said: Don't diesels have plug warming? I No, they have "glow plugs" to warm the engine. Diesels are "compression ignition" engines - they rely on the compression pressure to build enough local heat to ignite the fuel when it's injected. On a cold engine that's problematic, so most diesel engines have these "glow plugs" to electrically generate a local hot spot for cold starting. They're not used once running. Link to comment Share on other sites More sharing options...
Chris A Posted January 16, 2022 Report Share Posted January 16, 2022 10 hours ago, dougbgt6 said: I had a Peugeot 406 which had a 15 second delay on start up to warm the plugs. In the past there was quite a delay between turning the key and the glow plugs getting to temperature. My current modern diesel with push button stop/start system stats up in the time it takes to put the seat belt on. Link to comment Share on other sites More sharing options...
PeteH Posted January 16, 2022 Report Share Posted January 16, 2022 18 minutes ago, Chris A said: In the past there was quite a delay between turning the key and the glow plugs getting to temperature. My current modern diesel with push button stop/start system stats up in the time it takes to put the seat belt on. True. The Merc; Glow plug light on the dash no sooner seems to come on, than it is off again!. (# 5 needs replacing, I know, but will wait for the next "big" service!) Noticed that Friday, we had about 2C here at the time. Whereas some of the old lorries seemed to be "on" for several minutes. Link to comment Share on other sites More sharing options...
GrahamB Posted January 16, 2022 Report Share Posted January 16, 2022 My friend had a narrow boat, the diesel engine of which had Hot Bulb starting. Before attempting to start the engine you placed a blow lamp ( a proper brass one with a pump built into the paraffin tank) on a shelf attached to the side of the engine. The flame was directed onto a metal rod that passed into the side of the combustion chamber. Once the rod was hot enough, you could attempt to manually start the engine by spinning the massive flywheel. Once running, the blow lamp could be removed. Glow plugs and electric starts are just not fun. Link to comment Share on other sites More sharing options...
Chris A Posted January 16, 2022 Report Share Posted January 16, 2022 21 minutes ago, GrahamB said: My friend had a narrow boat, the diesel engine of which had Hot Bulb starting. Before attempting to start the engine you placed a blow lamp ( a proper brass one with a pump built into the paraffin tank) on a shelf attached to the side of the engine. The flame was directed onto a metal rod that passed into the side of the combustion chamber. Once the rod was hot enough, you could attempt to manually start the engine by spinning the massive flywheel. Once running, the blow lamp could be removed. Glow plugs and electric starts are just not fun. Same as with old tractors Link to comment Share on other sites More sharing options...
Steve P Posted January 16, 2022 Report Share Posted January 16, 2022 When i worked in a bus garage back in the day, when it was freezing, to start the Leyland Nationals we used to light a paper torch and stick it near the intake, fired them up quicker. Steve Link to comment Share on other sites More sharing options...
SpitFire6 Posted January 16, 2022 Report Share Posted January 16, 2022 13 hours ago, dougbgt6 said: Don't diesels have plug warming? I had a Peugeot 406 which had a 15 second delay on start up to warm the plugs. Once you get below zero batteries loose capacity alarmingly. db Hi, Car batteries internal resistance increases as temperature drops so that less current is available. The batteries Energy remains constant. I have heard it recommended to try to pull some Amps thru the battery prior to starting to "warm" the battery up. Makes sense. Cheers, Iain. Link to comment Share on other sites More sharing options...
ahebron Posted January 16, 2022 Report Share Posted January 16, 2022 5 hours ago, SpitFire6 said: Hi, Car batteries internal resistance increases as temperature drops so that less current is available. The batteries Energy remains constant. I have heard it recommended to try to pull some Amps thru the battery prior to starting to "warm" the battery up. Makes sense. Cheers, Iain. Especially for modern lithium batteries. Link to comment Share on other sites More sharing options...
SpitFire6 Posted January 16, 2022 Report Share Posted January 16, 2022 19 minutes ago, ahebron said: Especially for modern lithium batteries. Modern LiPo4 are able to be discharged below zero C. It is prohibited to charge below 0 C. Link to comment Share on other sites More sharing options...
Colin Lindsay Posted January 16, 2022 Report Share Posted January 16, 2022 21 hours ago, dougbgt6 said: Don't diesels have plug warming? I had a Peugeot 406 which had a 15 second delay on start up to warm the plugs. My Series 3 Landy had that, you turned the key and waited, then cranked the engine. More modern versions had a light that went out to tell you when to crank. My current diesel just starts straightaway. Link to comment Share on other sites More sharing options...
dougbgt6 Posted January 16, 2022 Report Share Posted January 16, 2022 As you can tell I know little about diesels, well little about anything really! Doug Link to comment Share on other sites More sharing options...
Pete Lewis Posted January 17, 2022 Report Share Posted January 17, 2022 the good o;d days of an Amal reservoir and giant electric fire inside the manifold when heat wait , wait wait crank up cant see for smoke aha off we go was a common thing on many diesels mind you a TS3 would start on just a hint of a crank as many found out when fitting a new clutch , next bolt varooma bing bang bong and had not jammed the stop control out Pete Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now