From: "Glen Gustafson" Date sent: Wed, 25 Aug 1999 23:45:08 -0700 To: 80_series@sgiblab.sgi.com Subject: Re: [80] Penrite Oil Send reply to: 80_series@sgiblab.sgi.com >>If this is the case, then running something like a 20W-60 should be a good >>thing surely?. Moreso, it shows that the lighter the oil, say 10W-30, the less >>protection it can provide for a motor under stress. Oil is a tricky subject. I do remember reading somewhere that multi-vis oils with a wide range relied heavily on polymers that actually resulted in lower performance in overall lubrication, which is supposed to be the reason 10-40 has fallen from favor with manufacturers. My impression is that oil has to be thin enough to get where it is needed, so pressure alone is not a good indicator of how well an engine is protected. Seems that having an oil with appropriate viscosity for the temperatures expected is better than having a multi-vis with too wide a range. -- ___/^^^^\ _/ ^ \ / `----- | /\ \ | \ | _____| \__ _______________/ / \ \ / _____/ \ \__ ______________/ / \ \ / / \_____ \ /|\ ##| ##########################/|\ ############ |#################### # \ ____ GLEN GUSTAFSON | # # ) ** Cinesite Hollywood ** /|\ # # motion picture digital imaging (323) 468-4405 # # A Subsidiary of the Eastman Kodak Company # ###################################################################### From: "Norm Needham" To: "80s COOL" <80_series@sgiblab.sgi.com> Subject: Re: [80] Penrite Oil Date sent: Thu, 26 Aug 1999 19:02:02 +1000 Send reply to: 80_series@sgiblab.sgi.com From: Glen Gustafson >pressure alone is not a good indicator of how well an engine is protected. > And this just might be the crux of the matter. Apart from the fact that high oil pressure can indicate lack of lubrication (blockage) to some components, the presence of oil is much more important than the pressure or flow at which it is circulating (for lubrication). Hey, I might be showing my alleged 90 years (thanks Mick;-) but I seem to remember some engines that relied on splash lubrication. Pressure and flow in modern engines are more related to the cooling function that the oil performs whilst ensuring the oil itself does not overheat in critical places. Logic says that LOW oil pressure (higher flow) might be beneficial in keeping both the oil and the engine components cool(er). I would like to hear Roger's comments on this. Cheers * Norm Needham * * Traction 4 / ARB Northside * Sydney, Australia * Trac4@bigpond.com