How to determine correct Oil Capacity

[bruce]

Hi,
SR20DET engine swap. The SR20 has a few different versions with difft oil capacities, so even finding the correct amount is difficult.
Typhoon sump fitted, so capacity has changed. Asked Typhoon and they said add an extra litre. That is bananas, as the new sump is a much lower profile than the factory sump.
The dipstick has been modified, so raises more questions. Showing overfilled.
I drained and replaced the same quantity, around 3.5 litres, which is close to standard unmodded capacity. Typhoon were advising an extra litre!
I don't think I will ever know what is correct.
Ta
Bruce

[plohl]

Keep putting less, and less oil in until something stops working.

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[bruce]

Tis the reason for my question!

[Steampunk]

Good story.
Thanks for sharing.

[smy0003]

Jumped on the Penrite website and was surprised to read that the SR20DET takes 3.5L of oil, less than our tiny BP's.
Thai-phoon say their sump has increased oil capacity, but 1L seems like a lot extra.

[bruce]

I too was surprised that a 2 litre turbo has only 3.5litre capacity.
If you look at the sump it is flat and not bulbous like a factory sump.

[Aiming Faster]

You'd never want the puddle of oil in the sump to touch the spinning crank, at least stationary, or it would want to aerate.
Could you measure the volume of the sump sitting below the crank? LxWxH, reduce H by 2cm(?) windage clearance. Compare that to original sump sizing, that'd be a rough volume difference.
You'd be aiming to replicate factory oil height with your enlarged capacity.
If the unmodified dipstick doesn't bottom out on the new sump pan, wouldn't that be the original oil height still?
If Typhoon suggest an extra litre, they may have calculated that will still sit below the crank?

[bruce]

Dipstick spout has been lengthened a little.
It sounds like there is no straightforward way to measure...

[manga_blue]

You measure the oil level in some engines and gearboxes with an over-long dipstick that reaches easily to the bottom of the sump. You just feed it in until you feel it tap the sump. That gives you a direct reading of how deep the oil really is in the sump, rather than how far down from the top of the conventional dipstick it is. The metal strip out of a windscreen wiper blade works well.

[RS2000]

That's ok if the engine has the correct amount of oil in it, but OP wants to know the correct upper level.

All I can suggest is find someone with a standard sump SR20, filled with 3.5L of oil (including filter) & insert your dipstick. Don't insert all the way, just to the equivalent height of your extended filler tube, then mark the level on your stick.

[NitroDann]

You want as much oil as you can fit without causing windage issues.

Do you know the height of the pickup?

Assuming the pickup is the right height you just have to fill it as high as it will go without the crank hitting it.

This is easy to figure out by just visualising where it sits, consider it's size and location based on the crank nose Bolt.

Then calculate the volume of the sump below that point.

Dann

[greenMachine]

Dry sump FTW.

[bruce]

Thanks for the advice guys. It will take some point to figure this out.

[hks_kansei]

I'd just look up what the standard SR20 should have.

Then what the extra size sump has extra. (1litre as you said)

Add stock to extra, then you have total capacity.

And subtract maybe 300ml to cover the stuff that doenst drain during a change (most engines have about 1litre safe zone from low to high)

Add the measured amount then see where it sits on the dipstick and use that as your normal level next time.