| Re: [GMCnet] Oil WARS ( again) [message #163902 is a reply to message #163899] |
Thu, 22 March 2012 21:04  |
Bob de Kruyff
Messages: 4260
Registered: January 2004
Location: Chandler, AZ
Karma:
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Senior Member |
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| JohnL455 wrote on Thu, 22 March 2012 19:03 |
Most likely a broken-in flat hyd cam will be fine with even then SN oils now on the shelf provided you run stock valve spring pressures, and a non insane cam profie (most MH grinds are not) The way I understand SM to SN update did not lower ZDDP but made other improvements. Though ZDDP is lower these days, there are other additives in the newer oils that can act as friction modifiers. What it really comes down to is spring pressures and how agressive the cam is and if you have a muliplier in the rocker (higher lifter foot pressures). Or if the lifters and /or cam are offshore junk. All that said staying around 1200 PPM is cheap insurance and not so much necessary on the road, but our vehicles have a more severe wear issue after long (months) oil drain down periods between starts. This is where it may help. Again, owning a GMC is like owning a horse----everyone has a different twist on how to maintain. Just MHO.
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Well said John
Bob de Kruyff
78 Eleganza
Chandler, AZ
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