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DannoXYZ

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DannoXYZ last won the day on May 6

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About DannoXYZ

  • Rank
    Moto Grand Prix Racer

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  • Location
    SF Bay Area
  • In My Garage:
    CB125T Ninja EX250E EX250F EX250J-racebike CBR250R-MC19 CBR250RR-MC22 NSR350 VF500F CBR600RR VFR750F

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  1. Yeah modern oils are simply magical compared to what was available just couple decades ago. I wonder what differentiates "type of engine"?
  2. interesting... so it's like sand in a way. At low velocities, you push it aside and sink. But hit it harder and faster and it "thickens" to support higher loads.
  3. uh... gears don't use hydrodynamic wedge for lift lubrication. There's actual contact and EP/ET additives are used in pH basic solution. It's actual heat of contact that melts these additives into super-hard wear-resistant deposits on gear-surfaces. Note that there's not much oil-flow in transmissions. Flow is not needed for lubrication. So you're saying flow-difference between different grades of oil is not significant? Well, about 10 of these Porsche engines were victims mysterious "#2 rod-bearing" failures. Seemingly occurs when increasing redline beyond factory v
  4. Yes, just having oil in bearing-clearance is all you need. Trick is getting it and keeping it there. At higher-RPMs, oil is pushed out of clearances and needs to be replenished faster. For example, in 1989, I dropped my VF500F in driveway and it toppled over onto rock on edge of driveway. Punched hole in lower clutch-cover and I lost all oil. Being stupid teenager, I just rode gently from Saratoga back to my brother's place in Milpitas; a 30-mile trip. With no oil. I kept RPMs low and throttle as low as possible, creeping along @ 50mph on freeway. My dad told me I probably destroye
  5. The "flow" we're interested in is difference in velocity between boundary-layer that's in contact with journal and bearing-surfaces vs. layers closer to centre of bearing clearance. Boundary-layer's velocity is zero relative to journal and bearing-surfaces. This difference in velocity creates the hydrodynamic wedge that lifts surfaces apart. Some good reading material: https://www.sae.org/publications/technical-papers/content/260008/ https://ntrs.nasa.gov/citations/19910021217 http://www.cscos.com/wp-content/uploads/NY1389_Lubricants-and-Lubrication_Sachs.pdf https:/
  6. How does an aeroplane stay afloat? Where is higher-pressure area on its wings? And what velocity is this flow relative to other side of wing? If flow is all that matters, why don't we use water or kerosene as engine-lube? Those will certainly flow more and faster than oil. Try these tests: 1. turn on air-compressor @ 50psi, put on sprayer nozzle and aim up. Put spray-can cap over nozzle and push button. 2. turn on air-compressor @ 100psi, put spray-can cap over nozzle and push button. Which cap flies higher and faster? What's difference bet
  7. Don't know if it was here, but I remember seeing study where they collected oil-samples from various bikes at 1st oil-change and analyse them. Japanese was cleanest, Italians weren't much better than Chinese. Anyone have link to this thread or to study itself? thx
  8. Thanks for useful data! Let me see if I understand this correctly: 10-40 = thin smear on magnet 0-40 = significant blob/small pea 10-30 = significant blob/small pea I suppose one way to objectively quantify this over time is to rinse off the stuff captured by magnet with acetone into petri dish. Letting it dry and then weighing it. Store it in separate jars and continually add more metal powders over time with each oil-change to get a running average.
  9. Thermostat rating is fully-open setting and is start of temperature climb. Just cruising around town under partial-throttle is enough to fully open thermostat on bikes in 20C or 30C climates. Then fan kicks in @ 104C. However... Note that ambient air-temps outside changes delta-T across radiator and affects how much heat can be shed by radiator (BTU/sec). As result, even though fan kicks in at same temp on both bikes, one in 20C and one in 30C climate, higher-temp one will end up with higher coolant & engine-oil temps for same loads because radiator sheds less heat in same a
  10. Breaker will work. Be sure to get combo thermal-magnetic unit with decent arc-suppression. Very different than AC breakers we're most familiar with.
  11. Note that problems start with bare brass spade connectors in factory wiring; which corrodes over time and causes overheating. So always upgrade specs to tin or zinc-coated connectors. Another problem is current capacity. Highest-rated 1/4" spade connector handles only 24-amp! Honda uses it in 30-amp circuit! So of course it'll overheat and burn. There's special connectors made for higher-current with better springs: https://www.delcity.net/store/Maxi-Fuse-Modules/p_820374.h_820405.r_IF1003 Or use bolt-on maxi-fuse holder: https://www.delcity.net/store/MAXI®-Fuse-Blocks/p_9241
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