13 replies to this topic

[movistar600]

hello ,

 

what oil do u suggest for topping up the chamber in su carb on a 1990 998cc  ?

also how far do I fill it ?

 

many thanks

 

[Alex_B]

This is also a much debated topic on here, I personally use the same as the engine oil 20w50 in my carb but lots of people use 3 in 1 and even things like olive oil, it depends how your engine runs, but experiment, its not hard to drain out and try another oil, and you fill it to the level if you look into the tube you will see a ridge and up to there, any excess gets removed anyway so its no biggy and provided there is resistance when you put the plunger in its doing its job :) 

[KernowCooper]

Most use 20/50 motor oil which I use without problem, SU do a dashpot oil but its a bit thin imo when the 20/50 works ok, fill the centre up to within about 8mm from the top if you overfill it its just comes out and eventually gets burnt through the carb

[movistar600]

thanks v.much  :)

[Mini 360]

20W50.  Done.

[surfblue63]

I use SU Damper oil. It's 20SAE grade oil and is what SU recommend and sell to fill the dampers on the carb.

 

http://sucarb.co.uk/...e-grade-20.html

 

Most good Mini parts suppliers stock it or get it direct from Burlen.

 

Why anyone would try anything else is beyond me, seeing as a carb is precision instrument and using the wrong grade of oil could lead to incorrect fuelling.

[Tamworthbay]

Moved to technical section

[Mrpeanut]

I use 10/40. The su stuff and 3 in 1 are very thin and 20/50 is too thick in my opinion.

Like others say, it depends on your car and is a trial and error thing.

[Gremlin]

I use SU Damper oil. It's 20SAE grade oil and is what SU recommend and sell to fill the dampers on the carb.
 
http://sucarb.co.uk/...e-grade-20.html
 
Most good Mini parts suppliers stock it or get it direct from Burlen.
 
Why anyone would try anything else is beyond me, seeing as a carb is precision instrument and using the wrong grade of oil could lead to incorrect fuelling.

As long as you put the same stuff in all the time and then get the engined tuned, it is fine

[krusher74]

I use 10/40. The su stuff and 3 in 1 are very thin and 20/50 is too thick in my opinion.

Like others say, it depends on your car and is a trial and error thing.

If SU oil is 20sae isnt that just the same as 20/50 as 20/50 is 20 when cold, (never going to get very hot in the carb) that would be why SU oil isnt a multi grade a there's no point in a carb.

 

if you use 10/40 your basically using 10.

[jaydee]

It depends on how rich it is running under acceleration

Thin oils tend to create weak spots

Thick oils tend to slow acceleration

Theres no magic formula..

[Tommyboy12]

I used to use 3in1. Now I use 20/50. It gives a smoother pick-up on my engine if I floor it from cruising.

[Bazooka Joe]

I've used automatic oil in it in the past (Dexron III), but can't say I've noticed much of a difference compared to 20/50, although I think I might need to pay more attention!

[cal844]

45ml of 20W50 engine oil all year round