22-10-2017, 05:42 PM
(This post was last modified: 22-10-2017, 05:53 PM by Nick Turley.)
Here are my thoughts to add to the discussion :
"Spit and hope" 2 bearing engines without external filters best on straight 30 SAE no detergents.
This however does require the sump to be removed and cleaned say every couple of years.
The sludge is the carbon dropped out of suspension and therefore not really doing too much damage.
"Spit and hope" 2 bearing engines with filter best on a good quality multigrade detergent oil.
Pressure fed - I always use an external filter with these.
Then run in on cheap multigrade mineral oil initially when the engine is newly built .
Change to the best quality silicone oil once the rings have "cracked" in.
As Ruairidh suggests the inside of an engine needs to be really clean to start with.
Not an easy thing do.
Back axles I always use EP140 on the advice of the chemists at Millers - they tell me that it does not affect bronze or brass when using modern formulations. I would be cautious about "old" oils in this regard.
They further told me that wear using EP140 is much reduced.
Following this advice I can report that the oil seems pretty clean after many miles.
Interestingly they still make non EP for those that do not choose to believe them !
"Spit and hope" 2 bearing engines without external filters best on straight 30 SAE no detergents.
This however does require the sump to be removed and cleaned say every couple of years.
The sludge is the carbon dropped out of suspension and therefore not really doing too much damage.
"Spit and hope" 2 bearing engines with filter best on a good quality multigrade detergent oil.
Pressure fed - I always use an external filter with these.
Then run in on cheap multigrade mineral oil initially when the engine is newly built .
Change to the best quality silicone oil once the rings have "cracked" in.
As Ruairidh suggests the inside of an engine needs to be really clean to start with.
Not an easy thing do.
Back axles I always use EP140 on the advice of the chemists at Millers - they tell me that it does not affect bronze or brass when using modern formulations. I would be cautious about "old" oils in this regard.
They further told me that wear using EP140 is much reduced.
Following this advice I can report that the oil seems pretty clean after many miles.
Interestingly they still make non EP for those that do not choose to believe them !