richbogle

what oil will i run in my cosworth? iv got a miniral oil in it the now just 4 a few mile coz i gave the bores a wee deglaze when the head was off getn the guides and stem seals done.but its smoking abit when i pull away from lights when its warm.had this b4 and it was stem seals but decent ones went bk on head.cld it b the shity oil?? what oil will i get, a 15 50 or a 10 60? heard both are used

martysmartie

iTrader: (1)

I would ditch the mineral oil it's rubbish! This may well be all that is causing it. I use 15/50 some say they run on 5/30 but would never use this personally, it's to thin! The popular brands are Silkolene, Millers or the very expense but good Castrol RS Edge 10/60.

Martin

SS1

iTrader: (3)

Silkolene PRO S 10W-50

richbogle

thanx. what will be best tho? thers millers 10 60 i think iv seen. whats the diffrence between the 2 ov them? thickness?

tabetha

The castrol edge would need to have improved massive over the castrol RS mix, as that really was shite.
A 30 is way too thin, I favour a 50 weight in a fairly tight engine, but a little more worn use a 60 weight, don't worry about the first number as it relates to temperature when cold which isn't the issue here, I'd use the Silk Pro s of millers 60.
tabetha

MarkN

I recently asked the same question on here. As I couldn't get hold of Silkolene locally I opted for Mobil 1 Motorsport 15w50 which was also recommended.

Anyway - the car seems much happier on it than it has been on the Ford stuff I'd used previously. Oil consumption is reduced, the car seems happier and even the oil pressure sits slightly higher on the gauge. I'm very pleased with it and would definitely use it again.