There have been many posts about optimum oil levels before with modified engines and modified sumps etc. I thought this was an interesting post by Caterham aftersales regarding CSR200 and 260 oil levels.

Im not wishing to prompt hijacks about wether people think the advice should have been posted or not - but interestingly they report that it is normal for tuned engines to breath a little oil when driven enthusiastically (not a little - not lots). The advise that if yours doesnt, add 250ml of oil at a time until it does then note what the oil level is on the dipstick and maintain that level.


What you need to determine is how you define 'enthusiatsic driving' but the theory sounds like it could be employed on all our cars.

http://www.blatchat.com/t.asp?Id=144489

no reason not to post the advice but was is the reaosnign bheind it?

pour in oil until is starts to come out of the engine - what is causing that to happen?

if you keep ading oil to an engine then surely the nextthing to happen is the crank starts churning it up resulting in aerate oil - not a good thing. presumably when that happens, you top up just to below that point.

The reasoning behind the post was that it has been subject of discussion in the past and here was an alterbative view on determing where the natural oil level of a modded engine is.

The point is not to keep adding it until the crank whips it up - far from it. The point they are making is that particular engine, in its state of tune, will throw a very small amount out if its driven hard (ie trackday). It is also sensitive to oil starvation therefore they suggest if someones isnt breathing a little then it may well need a top up - hence the addition of 250ml at a time being suggested.Now there are several other types of engine that display similar characteristics, mine for one. So following that advice adding a little at a time to find the happy level seems good advice. Add too much and the breathing is excessive. Add way too much and the crank hits it and causes way too many issues to dig up again.

Summary - this post is about fine tuning the upper oil level on dipstick to suit a particular engine.

Or just have a tuned crossflow - mine would chuck out whatever was in it , regardless of the actual level