Engine oil dirty so quickly..?

Never really bothered me but would like an answer if there is one. The Midget had the same problem after about a few weeks or so the engine oil would look very dark like it need to be changed. I had the engine out of the midget when I changed the clutch removed the oil pan and the engine was crisp clean. is it just a british car thing? GTX is the only oil I have used in the B that has didn't get dirty but still became dirty much faster then any other car I have seen.

Tractor engines tend to do that.:thumbsup:

Which oil filter are you using? If you're using the old type where you change the element and not the whole filter, it's not as efficient as a modern filter. Get the spin on adaptor (I prefer the adaptor for the inverted oil filter) then use a good quality filter and the oil will be better. It will still darken with age but it won't be dirty. Best of luck. Basil

[quote=MrMarty51]

Tractor engines tend to do that.:thumbsup:[/quote]

I know the 1275cc was used in farm tractors but not the 1800cc..?

Basil, I am using a bosch filter caster type, stock on the 78B.. I have used all kinds of oils and filters same results.

It seems to be really dependent on the chemistry in a given engine. My engine keeps the oil clean much longer than it did pre-rebuild, but it still gets dirty faster than the Miata.

If engine running temp is too cold ,,that can cause it !

If an engine is running rich and has some ring blow-by, it will darken the oil with carbon.

the color or appearance of the oil has no bearing on its ability to function properly.

I have noticed my B oil seems to darken quickly if I'm over-rich on the mixture. NO science behind this observation.

[quote=scottydawg]

If an engine is running rich and has some ring blow-by, it will darken the oil with carbon.[/quote]

Agreed. Plus running really rich doesn't help the rings/cylinders to last very long which contributes to more dirty oil.

modern cars have fuel injection (i.e. more precise metering) and are designed to run a little leaner.

no big deal.

The detergents in today's oils tend to darken it pretty quickly as they clean old inner-surface contaminants, especially in older engines. Nothing to worry about...the detergents are doing their job.