Engine Oil & Last Century Porsche's , some light reading abservations

[Buchanan Automotive]

16 hours ago, Peter M said:

Bruce,

Thanks for your comments.  What MPa.s range do you recommend for the last century 911's, 944's and 928's that most PFA's drive on the street?

 

Thanks

Peter 

Hi Peter , I do not do that for very good reason , its near meaningless in what 98% people think it might suggest or even misinterpret or worse , so no point at but also because when one picks up a ( say ) 5L  or a 4L plastic bottle of any engine oil sold in Australia & other countries , you will not see on the labelling the "High Shear Rate Viscosity mPa's at 150 deg number , its just not there at the point of sale & if it is one or two obscure oil company labels , then I haven't seen it , so the number/s are useless to the average owner who is way too busy trying to get his/her latest mobile phone to work , let alone tying to find out numbers of something they they are not really sure what it means

In basic terms , for what we have experienced over the decades , seen over & over & over & over is that there is a correlation between high oil film strength engine oils = 15w-50 & mostly 20w-50 ) for max engine internal component life for normal street driving in last century Porsche engines ( 944 , 928 , 911 air/oil cooled engines ) where the ambient temp range is between -10 deg cel to unlimited high ambient temps = Australian conditions

If I stick to the basics , then the average owner of a last century Porsche ( if they see these posts ) will have some idea of how important a  20w-50 engine oil / high oil film strength engine oil is in a last century Porsche road engine

Regards

Bruce B  

[Peter M]

So your message Bruce is keep it simple!

Quality brand 20w-50 (which by definition guarantees a HTHS of greater than 3.7 Mpa.s), a good dollop of ZDDP, say greater than 1000 ppm and spend your time worrying about something else?

Thanks again for your comments.

 

Regards

Peter 

[OzJustin]

On 05/01/2018 at 5:13 PM, Buchanan Automotive said:

Hi Justin , 90+% of the time is just new valve guides,  exhaust guides are the ones that wear more than inlet guides  , 10% of the time its some or all new valve/s because of the valve stems are worn as well & the valve heads are just too far gone , meaning( for road conditions) its mostly the very high km engines that will have the need for some or all new valves 

100% of the time every cylinder head that gets removed & dismantled for machining & possible valve guides , all heads get new valve stem seals 

Regards

Bruce B

Hi Bruce

Thanks very much for the info re the valves. This is an area I’m sure many of us will keep in mind when investigating wear in the top end of the engine.