Technical Figuring out oil capacity

Figure out oil capacity ??

just look at the dip stick !

gosh, with to much, or not enough pot.
Let that brain cool off
Too much thinking.

 

not always that easy - have seen more than one aftermarket dipstick that was marked wrong - some are "universal", and people never mark them for their motor - others have marked the stock dipstick incorrectly

 

Here is the video I forgot to add to my last post. Went back and added it. Sorry bout that!
Skip to the 2:30 mark............

 

That's the type of answer I was exactly NOT looking for. Too bad I'm too drunk at the moment, I have no pithy or otherwise well thought out reply.

I don't give a hoot what the stupid dipstick says. I'm looking for an engineering answer, not a parts changer answer. Why is the oil level engineered to be where it is is what I was looking for. LOL overthinking.... What an answer.

THAT is why I lurk. Thanks but I'll get it on my own. Good day parts changers.

 

Oil capacity, from what I have been taught in trade school covers a bunch of issues with the engine.

1. Is quite obvious Lubrication, the engine needs enough oil to keep its vital parts lubed.

2. Depending on the amount of oil in the pan, extends oil changes. 12 litres in a Mercedes v8 equals 16,000 km between services
A Mazda or Toyota 4 banger with 6-7 litres of oil can go 8-10,000 kilometres.

3. Covers a bunch of grey areas such as engine life, emission control, noise, heat and cooling.

sorry you think we are a bunch of parts changers, but even after 5 years of college, multiple corses and almost 25 years in the trade, I don’t have a straight and black and white answer to this question.
So just like most on here I go by the manufacturer recommendation and look at the dip stick.
Some engineer got paid big bucks to make sure that thing makes sense for the engine it’s in.


Parts changer signing out !

 

VW among others use "Longlife service" with oil change interval up to 30 000km. Sure, there has been some issues and I'd prefer to change oil more often, but this factory interval is way longer than the numbers you mention.

 

This isn't an engineering forum, it's a hot rod forum. Good luck in your search.

 

This is exactly what I need to keep in mind. I say this with out meaning insult but I see this board as an anchor of knowledge. It is also the internet after all where everyone's opinion has meaning and they're free to express that opinion. And that's fine, but no one, and I'm not counting the 2 outliers out there, needs to be told to check the dipstick as a reply to that question. Duh, yeah, thanks.

I think you guys generally know your stuff, that's why I came here and asked. And I've been ignoring the nice to know replies and conversations, that's all good. But the look at the dipstick bit sort of... well I should have ignored that too.

There's lots of books out there but I tend to want quick answers, not bogged down in reading. I'd rather be in the garage. But for this I'll have to read.

 

If your wondering about your dipstick, wouldn't you put the recommended amount in then read the dipstick? Lippy

 

As far as why the certain amount I suggest you get ahold of the engineers at GM, Ford or whatever and ask them? And I'm not trying to be smart. They may give you an answer. Lippy

 

So say you just started at GM and had nothing to do so you get given the job of sump capacity.
I’d go about it by measuring the diameter and length of every oil passage ( would be on the blueprints) oil pump and filter capacity. Then a mathematics guess at how much oil is contained within all crank cam and rocker arms bearing/shafts and lifters when running. Now you have a bare minimum , but you need to cover the oil pick up at all times during normal use, add that in . Now consider how much might get stuck up in the heads (drain back) add a bit for that. Add in what’s sitting on the crankcase walls , cylinder walls etc ( I bet they have a number for that you could just use) Add in the bit for normal use ( that which gets burnt off ) you cant run minimums on the road, race car maybe, this is the bit above add on the dipstick . So now you need to design a sump that fits the car and carrys your oil. The oil needs to be kept away from rotating parts , you don’t want airated oil or windage losses. You might need baffles to keep the oil around the pickup. Then I’d suggest some dyno time to confirm drain back and oil use at the upper rpm limit. Add a cooler and remote filters and you have more work to do. Then some road testing. If your making a sump the manufacturer probably has the capacity correct. If your going much higher in rpm you really need to look at the level in the sump at the new max rpm (on an engine dyno). Easiest is to buy a sump and pickup someone else designed and tested.
TMI?

 

And the ironic thing is that checking the dipstick will actually give the engineering answer. Because the dipstick marks were specified by the engineer, to keep the oil level where it really needs to be.

Whatever, it's another fun HAMB thread.

 

There are so many variables between the way the vehicle will be used. I would say the manufacturers as stated would do dyno at different rpm and load levels and real world testing of a lot of different conditions to come to an answer. Like outrunning the cops, going to the grocery store ect... LOL. Lippy