tag:blogger.com,1999:blog-6498413430541424627.post8812452686974706196..comments2023-11-29T01:47:52.439-07:00Comments on clarity2010: Octane - don't knock itRelax Maxhttp://www.blogger.com/profile/01051381168322495999noreply@blogger.comBlogger6125tag:blogger.com,1999:blog-6498413430541424627.post-12414909274122794552011-01-27T12:39:32.675-07:002011-01-27T12:39:32.675-07:00Well, you insert the starting handle into the dog ...Well, you insert the starting handle into the dog (are you still with me?) on the front end of the crankshaft and use it to crank the engine until it starts. <br />I have a starting handle for my land-rover. It used to be quite easy to start that way, until I gave it new piston-rings and reground the valves. <br />Either that or the engine rebuild coincided with me getting weaker.<br /><br />Some older diesel engines, such as boat engines and those used in building-site dumper trucks, were started with the starter handle, but you flip a lever which opens a "decompressor" valve on the cylinders. Thus the engine is easy to turn over, and you build up speed on the flywheel, once you judge that to be enough, you flip the compression lever back, and the engine bursts into rattling black smokey life.soubriquethttps://www.blogger.com/profile/01151288534629885195noreply@blogger.comtag:blogger.com,1999:blog-6498413430541424627.post-18962076989871525632011-01-26T19:01:20.428-07:002011-01-26T19:01:20.428-07:00@Stephanie Barr - Thanks. I like learning new thin...@Stephanie Barr - Thanks. I like learning new things too. Believe it or not. :)<br /><br />@Soubriquet - Mayhaps, indeed. But that post will be in another series which simply discusses how a gasoline engine works, rather than combined in this series. I need to back off this topic for awhile and try to regain some of the readers that always drift away when I do this. :)<br /><br />I have noted your use of "starting handle" and added it to my growing list of BritishSpeakisms. It's a "crank" - and the trick is to put your thumb on the same side as your fingers. (As well as retarding the spark. You left that part out.)<br /><br />@Jeff King - Well, thank you. I promise to change the subject now. I do appreciate your loyalty here.Relax Maxhttps://www.blogger.com/profile/01051381168322495999noreply@blogger.comtag:blogger.com,1999:blog-6498413430541424627.post-53428984783791878082011-01-26T15:15:12.856-07:002011-01-26T15:15:12.856-07:00I'm leaning a lot, thx all.
great post.I'm leaning a lot, thx all.<br /><br />great post.Jeff Kinghttps://www.blogger.com/profile/00667419764890599092noreply@blogger.comtag:blogger.com,1999:blog-6498413430541424627.post-37543469565521779862011-01-26T11:18:49.586-07:002011-01-26T11:18:49.586-07:00Mayhap you were going to speak further on the subj...Mayhap you were going to speak further on the subject of "knock", and explain that it's all down to the speed of the flame-front in the fuel-air mixture. If the spark occurred before before the piston reached top-dead-centre (tdc), then too rapid a flame-front meant that the expansion of combustion gases tried to hammer the piston back whence it came, maybe damaging the engine. The spark, ideally, is timed to occur before tdc, but the full combustion of the fuel-air mix to occur when the piston has started its downward return. <br />From there you could get into how the distributor, with the help of a vacuum-diaphragm, and centrifugal weights, would alter the point in the piston's travel<br />at which the spark occurred, in order to avoid knocking under load or harsh acceleration.<br />Nowadays, a computer, using multiple sensors, controls the moment and amount of fuel injection.<br />But in the old days, a driver had to do it all. There was a lever, often on the steering wheel, that allowed the driver to "advance" or "retard" the spark.<br />Retarding the spark was especially important in starting with a starting-handle. Ignition before the piston reached top dead centre (tdc) might result in a broken arm, through kickback.soubriquethttps://www.blogger.com/profile/01151288534629885195noreply@blogger.comtag:blogger.com,1999:blog-6498413430541424627.post-12343575623638872472011-01-26T11:01:21.878-07:002011-01-26T11:01:21.878-07:00My old Land-Rover, built in an era when lead was a...My old Land-Rover, built in an era when lead was abundant, would really prefer it to still exist. <br />One of the advantages of lead as an additive, was that it coated and protected the valve-seats and valve contact areas, and reduced wear erosion of these parts.<br />Modern unleaded fuels are unkind to older engines.<br />Also, when older vehicles, classics, maybe, which are not in everyday use, are stored with fuel in the tanks, some of the more volatile fractions of the fuel, like benzenes, tend to evaporate out, the remaining fuel mixture may further separate, with ethanols in particular tending to layer at the bottom of the tank. Corrosion increases, and a brown sticky varnish-like substance may coat components, and block filter-gauzes and smaller fuelways (like carburettor jets, for instance). Tetraethyl lead was indeed a toxic substance. But benzene is carcinogenic by inhalation or skin absorbtion.soubriquethttps://www.blogger.com/profile/01151288534629885195noreply@blogger.comtag:blogger.com,1999:blog-6498413430541424627.post-59506535938436531622011-01-25T19:20:41.186-07:002011-01-25T19:20:41.186-07:00Catalytic, great word. Now, see, I didn't know...Catalytic, great word. Now, see, I didn't know about octane, so I learned something. <br /><br />That's always cool.Stephanie Barrhttps://www.blogger.com/profile/17772217449161603561noreply@blogger.com