Headnig toward the Dark Side
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From: krusty kritter on 21 Feb 2010 11:13 On Feb 21, 7:44 am, totallydeadmail...(a)yahoo.co.uk (The Older Gentleman) wrote: > krusty kritter <breoganmacbr...(a)yahoo.com> wrote: > > Old style two valve motors take as much as 90 degrees of crankshaft > > rotation to fully burn the mixture, while modern four valve engines > > only take about 32 degrees of rotation. > > Has it occured to you that this is entirely dependent on engine speed? > > Answer: no. WRONG! Even though I didn't state at what specific RPM it takes "x" degrees of crankshaft rotation for combustion to be completed, I most certainly know that this is at higher RPM. > To help you understand this, let's imagine an engine turning at 1rpm. > The crank will have moved a fraction of a degree during combustion. Now > compare with an engine turning at 10,000rpm.... > > See? I see YOU offering a ridiculous example, because the engine isn't inhaling any useful mixture when it isn't turning 500 to 1000 RPM.
From: krusty kritter on 21 Feb 2010 11:30 On Feb 21, 6:47 am, "Snag" <snag_...(a)comcast.net> wrote: > krusty kritter wrote: > > Well, dyno testing and setting the idle mixture according to EPA > > emissions specifications isn't going to help Robert anyway. > > Who said anything about EPA specs ? When you talk about O2 sensors, you're talking about EPA emissions technology. > > The whole idea of opening up the idle mixture screw an extra 1.0 to > > 1.5 turns is to *waste* a little extra fuel at idle to cool the motor down > > by lowering combustion temperature. > That's also a great way to foul plugs at idle. So use spark plugs that are one heat range hotter or use extended tip spark plugs. > A properly tuned idle circuit doesn't need to "waste" any gas to "lower combustion temps" . Are you for real? There are NO internal combustion engines with aluminum pistons which do not run at sub-stochiometric fuel/air mixture ratios! Exhaust gas temperatures run around 1200 degrees with sub- stochiometric F/A ratios and the pistons survive because burn time isn't long enough to melt holes in them. If engineers ever built an all-metal engine that ran at stochiometric F/A ratios, they would have to use iron or steel pistons to survive the 3000 degree combustion temperature. The pistons would be three times as heavy as aluminum pistons, stress on the connecting rods and crankshaft would increase three-fold and the permissible RPM would be reduced. Experimental ceramic engines have been built, but I haven't been following that technology to know when they might become available. > It also eliminates the need to blip the throttle at stop lights to keep the > motor runnin' . So turn the idle RPM up a bit and run the engine at 100 RPM higher. This also circulates more oil and keeps the engine a little cooler that way. > > The oftener you open your mouth the more stupid comes out of it . Thanks. I admire you too...
From: The Older Gentleman on 21 Feb 2010 11:32 krusty kritter <breoganmacbrath(a)yahoo.com> wrote: > On Feb 21, 7:44 am, totallydeadmail...(a)yahoo.co.uk (The Older > Gentleman) wrote: > > krusty kritter <breoganmacbr...(a)yahoo.com> wrote: > > > Old style two valve motors take as much as 90 degrees of crankshaft > > > rotation to fully burn the mixture, while modern four valve engines > > > only take about 32 degrees of rotation. > > > > Has it occured to you that this is entirely dependent on engine speed? > > > > Answer: no. > > WRONG! Even though I didn't state at what specific RPM it takes "x" > degrees of crankshaft rotation for combustion to be completed, I most > certainly know that this is at higher RPM. So why didn't you mention it? As it stands you provided very specific measurements which are *meaningless* without rpm being given. Which makes your assertions valueless. > > > To help you understand this, let's imagine an engine turning at 1rpm. > > The crank will have moved a fraction of a degree during combustion. Now > > compare with an engine turning at 10,000rpm.... > > > > See? > > I see YOU offering a ridiculous example, because the engine isn't > inhaling any useful mixture when it isn't turning 500 to 1000 RPM. Yes, I offered an extreme example, to make you understand. And even then, you got it wrong. Some engines don't *inhale* and run at rather less than 500rpm. So you get it wrong *again*!!!! Well done. -- BMW K1100LT Ducati 750SS Triumph Street Triple Honda CB400F Suzuki TS250 Suzuki GN250 chateaudotmurrayatidnetdotcom Nothing damages a machine more than an ignoramus with a manual, a can-do attitude and a set of cheap tools
From: krusty kritter on 21 Feb 2010 11:53 On Feb 21, 8:32 am, totallydeadmail...(a)yahoo.co.uk (Buggrit) wrote: > Yes, I offered an extreme example, to make you understand. And even > then, you got it wrong. Some engines don't *inhale* and run at rather > less than 500rpm. Oh ferkrissakes! Isn't there *anything* better that an "Older Gentleman" could be doing with his Sunday afternoon than play word games with strangers 6000 miles away?
From: Snag on 21 Feb 2010 11:56
krusty kritter wrote: > On Feb 21, 6:47 am, "Snag" <snag_...(a)comcast.net> wrote: >> krusty kritter wrote: > >>> Well, dyno testing and setting the idle mixture according to EPA >>> emissions specifications isn't going to help Robert anyway. >> >> Who said anything about EPA specs ? > > When you talk about O2 sensors, you're talking about EPA emissions > technology. NOT ! I'm talking about a real-time way to analyze the exact fuel/air ratio . > >>> The whole idea of opening up the idle mixture screw an extra 1.0 to >>> 1.5 turns is to *waste* a little extra fuel at idle to cool the >>> motor down by lowering combustion temperature. > >> That's also a great way to foul plugs at idle. > > So use spark plugs that are one heat range hotter or use extended tip > spark plugs. So you want to put a bandaid on a problem you tuned into the bike ? > >> A properly tuned idle circuit doesn't need to "waste" any gas to >> "lower combustion temps" . > > Are you for real? There are NO internal combustion engines with > aluminum pistons which do not run at sub-stochiometric fuel/air > mixture ratios! ^^^^^^^^^^^^^^^^^ Did you just make that word up ? > > Exhaust gas temperatures run around 1200 degrees with sub- > stochiometric F/A ratios and the pistons survive because burn time > isn't long enough to melt holes in them. BULLSHIT > > If engineers ever built an all-metal engine that ran at stochiometric > F/A ratios, they would have to use iron or steel pistons to survive > the 3000 degree combustion temperature. BULLSHIT > > The pistons would be three times as heavy as aluminum pistons, stress > on the connecting rods and crankshaft would increase three-fold and > the permissible RPM would be reduced. > > Experimental ceramic engines have been built, but I haven't been > following that technology to know when they might become available. > >> It also eliminates the need to blip the throttle at stop lights to >> keep the >> motor runnin' . > > So turn the idle RPM up a bit and run the engine at 100 RPM higher. > This also circulates more oil and keeps the engine a little cooler > that way. Another bandaid for a problem you tuned into the engine . >> >> The oftener you open your mouth the more stupid comes out of it . > > Thanks. I admire you too... Admiration has nothing to do with it . You continuously put bad advice out , and just can't stand the thought that you could be wrong . I'm not always right , but at least I have enough self-esteem to admit when I'm wrong . Besides , tweaking your nose amuses me . -- Snag "90 FLHTCU "Strider" '39 WLDD "PopCycle" BS 132/SENS/DOF |