Semi synthetic

[norsa]

I've got a job lot of semi 75/90in the workshop. Legacy of when I serviced our fleet of mercs . Would it be OK to run in my midget ?
Nick

 

[Shox Dr]

Only in the back axle or gearbox.

For the engine you need something like 20/50, but dont take my word read the manual

Make sure the API rating is correct.

 

[norsa]

Thanks. I wasn't thinking of putting it in the engine obviously. I'd like to run R in the engine but apparently if it's run on std oil, changing it to R will result in fubar.

 

[Shox Dr]

'R' what's that.

No such thing as 'standard oil'

 

[FoxZulu]

Castrol 'R' presumably.

Standard Oil = Esso

 

[Gareth J]

There are some concerns with "modern" EP oils eating yellow metals.

Would be my only concern. But may not even apply, the midget may not have any brass wotsits, the oil may not be an EP type that supposedly affects them and even if it were, the rate of deterioration may be well below anything to cause worry.

 

[norsa]

Correct. castrol R. It was a classic mineral oil but was very thick when cold. Fantastic smell.

 

[colnerov]

Hi, GL5 spec oils eat the yellow metals ie. synchro rings in the Gbox, the diff should be OK. If the oil is GL4 spec then it should be OK in both.

Colin

 

[norsa]

Thanks to both above. Ill check the spec

 

[rtbcomp]

Some older bearings had brass cages in them, so I'd stick to GL4 in the diff unless you know for certain there's no brass in there.

 

[norsa]

Or maybe stop being tight and get some EP90. Its only a 4 speed marina box, cant take that much.

 

[taxi ray]

What is in the oil that damages brass?

 

[johnik]

Correct. castrol R. It was a classic mineral oil but was very thick when cold. Fantastic smell.

stick some in the fuel tank for the well thrashed smell effect,what i did on my bikes,as for using in an engine these days,i think it created gum / sludge if not changed regularly.

 

[slim_boy_fat]

^^ Yep, used to do that...........

 

[norsa]

One of castrols technicians is a member of my motor club and he advised against even doing that for fear of damage to the valves. How much did your engines run on it? Bearing in mind im doing 500 p.a i wonder?? Anyroadup this is the gear oil in question.

 

[Rig Pig]

What is in the oil that damages brass?

Some of the additives in modern oils corrode yellow metal, it's always worth checking compatible of oils, old stock oil of the correct viscosity but without additives can cause expensive damage too.

 

[johnik]

One of castrols technicians is a member of my motor club and he advised against even doing that for fear of damage to the valves. How much did your engines run on it? Bearing in mind im doing 500 p.a i wonder?? Anyroadup this is the gear oil in question.
View attachment 102626

just a splash,lid off the oil can should be enough to create the aroma

 

[FoxZulu]

just a splash,lid off the oil can should be enough to create the aroma

When I raced 2 stroke karts many years ago I always ran Castrol R in them. Because it degrades quickly when mixed with petrol any leftover pre-mix at the end of a meeting would get added a bit at a time to my Escort vans fuel so as not to waste it and because I had/have an addiction to the smell. I still add a few drops to the pre-mix in my Montesa trials bike purely for the smell even though I run that on synthetic. Incidentally, I always have a sniff of acetylene when purging the regs and hoses because that's another of my odd likes that takes me back in time