Increased crankshaft/bearing wear with stop/start systems

[NeilBlanchard]

The start/stop systems I have read about use the alternator as the starter; or a belt driven starter. No solenoid and no pinion gear and no ring gear.

[99kleansi]

Originally Posted by Frank Lee

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Basically they figure stop/start systems will go through 3x the number of start cycles than regular engines, and a start cycle is a cycle the crank and bearings experience lack of pressurized lubrication.

Of course if new bearing tech doesn't fix it, an oil pressurizing system could be added.

Those of you who extensively P&G might want to consider that 3x wear thing being a possibility for you...

Funny thing I mentioned this in a prior thread and you completly disagreed with me on this. There a re several solutions stated below that are in play or can be put in play... stated previously oil pressure needs to be up they same way we push start our sprint cars at the track and wait to flip the ignition on until PSI is high enough. We use to tear down those motors after every few runs and the most damage would be from lack of oil pressure protecting the bearing surface... Lots of composite bearing materials to play with that really play with the longevity

Almost every oil manufaturer has pull the entire Zinc content out of their oil which seems to have some pretty good benifits. Brad Penn oils still have a hefty amount in them so I run it in my motors. I am sure if someone did the testing it would probably increase MPG on a daily driven car. I know for a fact that it frees up HP on the dyno indicating a reduction in friction..... Seems way better then the claim to fame that Royal Purple has and half the price.

[Frank Lee]

You went way beyond bearings.... but yeah, I figured the extra stop/starts would disappear into the "noise"... I hadn't seen it quantified before, but for the purposes of the bearing mfg R&D they are calling it 3x.

[dennyt]

Originally Posted by NeilBlanchard

The start/stop systems I have read about use the alternator as the starter; or a belt driven starter. No solenoid and no pinion gear and no ring gear.

But belt-driven starters cause a crank bearing reaction too. The belt tension is converted to two reactions: torque (tension * crank pulley radius), and a bearing reaction, equal and opposite to the belt tension.




Coaxial electric motors, like on the Insight and the Prius, only exert torque on the crankshaft, not radial bearing load.