May 11th, 2018, 09:42 AM
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#15
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ninjette.org certified postwhore
Name: Bill
Location: Port Huron, Michigan
Join Date: Mar 2017
Motorcycle(s): 2007 Kawasaki 250 Ninja, 1982 Honda Ascot FT500
Posts: A lot.
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Quote:
Originally Posted by DannoXYZ
Yes, be very careful about using auto oils. Only use those with sufficient zinc ZDDP extreme-pressure/extreme-heat additives. Latest auto oils reduced ZDDP levels so low, that older cars with flat-tappets experienced top-end failures. Only auto-oils that didn't get reduction are 15w50 and 20w50 oils, I suspect because Porsche primarily uses that Mobil-1 oil. That reduction is probably why manual suggests newer API-grade oils must also have motorcycle JASO MA endorsements as well to make up for lost of ZDDP.
Note that hot operating weight on chart uses ambient temperatures as proxy indicator of actual engine-oil temps. That's OK if you don't have oil-temp gauge. Usage-type should also be considered as that's primary cause of oil-temperatures. If you're doing average type of stop-n-go driving, then chart is accurate; and 30-weight is perfectly fine for sub '86F usage.
However, if you're maintaining bike at WOT near redline under racing conditions, you'll want to go off right side of scale with 50-weight; even then it may not be enough. I've found most 15w50 or 20w50 actually drops oil-pressure at end of 20-min track session in +100F heat even with radiator-fan connected. The only oil I've found that doesn't do this is Motorex 4T 10w50 oil.
Here's tonne of great info on motor oils.
https://www.sportrider.com/oils-well...ds-well-part-1
https://www.sportrider.com/oils-well...ds-well-part-2 |
The four cylinder Offenhauser racing engine ran straight 50 weight oil. Engine warm-up was about 30 minutes (prior to starting the engine).
Bill
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Insanity: doing the same thing over and over again expecting different results each time.
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