Engine oil

[embee 7,288]

I think the procedure for running an engine then stopping and allowing a couple of minuted drain-down time is just a more or less standard procedure adopted industry-wide, it keeps things simple and gives a correctly representative reading.

 

I've done lube system development work on a number of engines and each one has slightly different oil hang-up and drain-down characteristics. Doing this procedure at least establishes a more or less consistent condition for you to check at. Dipstick calibrations usually allow for certain amounts of over and under-fill (which inevitably will happen), and usually anywhere between the max/min marks will be nicely in the safe range for the engine. The calibration will take into account the true running levels, allowing for the additional oil hang-up at higher speeds.

 

Quite a lot of bikes don't respond well to any amount of over-fill, gearchanges can get difficut etc, and you're almost guaranteed to get more carry-over in the engine breather. I usually set mine to mid-way on the dipstick. The Integra handbook recommends setting oil level with the bike on the centre stand (the only NC model with it as standard).

[shiggsy 529]

Yes every handbook I have ever read says the same thing so I'm not saying write or wrong way here but I wonder how someone feels when they run their engine, leave it a few minutes, check the oil and theres nothing showing on the dipstick. 

 

If checked cold that can't happen and if its on the max mark you know your not over filled and your certainly not under filled.  Its just always struck me as an odd checking sequence.

[embee 7,288]

Yes, but if that's the way the dipstick is calibrated then that's the procedure which will give "correct" readings. If you adopt a different routine it may give the same or similar readings, or it may not. You can always cross check one procedure against another, then use whatever suits.

 

The couple of minutes drain-down allows "free" oil to return to the sump but doesn't usually result in oil galleries and oil pumps etc to drain. If you leave it hours then these "trapped" oil volumes may or may not drain back. One engine I worked on had 2 distinct cold oil levels, depending on whether the gallery drained or not. When doing oil consumption tests we had to establish which of these conditions it was in when taking measurements, there was something like 100ml difference.

Edited October 16, 2014 by embee

[shiggsy 529]

Would it ever be significant difference, i.e damaging? 

[embee 7,288]

Try it and see. 

[shiggsy 529]

Have been for about 25 years 

[Scootabout 2,245]

I'd be interested to know the amount of oil required to take it from min to max on the dipstick. Can't see that in the book anywhere.

Me too. I added some oil when the dipstick showed some oil loss - not sure how much, maybe half or two thirds the way down between the upper and lower marks - and the result was over-filling. I maybe added a third of a litre. I then spent quite a lot of time syphoning it out, as I was paranoid about damaging the engine (yeah, would have been quicker to loosen the drain plug, I know).

So yes, it would be helpful to specify the amount in the manual, but in my (single) experience the answer would appear to be " not a lot".

[kharli 100]

has anyone noticed any oil use at all ?..I am on 35k miles and the dipstick stays constant between changes...ive noticed the oil gets very slightly more brown is all.  My breather tube has collected about an inch in all that time..i think mostly on very fast motorway work. Water level not changed either ,though that gets changed on valve checks (which really needed no adjustment either ,kinda wish I hadn't bothered doing them .)