When is Overfilled Really Overfilled?

[Leo]

I always thought there should be sufficient clearance between the oil at max level and the windage tray because they have to take into account the road gradient. There's no point having such a small clearance that you'll get aeration on small inclines. So 10% overfills shouldn't be a problem.

 

[BuickGN]

It's engine specific. I run the TL almost half a quart high.

When the GN engine was out for a rebuild I filled the oil pan with water just to see how much it took to get it within an inch from the top of the pan which is still far below the bottom of the crank in this deep skirt design. Factory is 5 quarts with filter change. I go it somewhere around 8 quarts and still in the safe range. I don't run it that high but I have no problem doing 6.5 quarts knowing it's still at least 4" below the crank.

 

[1993_VG30E_GXE]

Basically Buick, to do the initial fill after my overhaul, should I just put in the amount in the service manual WITH oil filter change?

My dipstick is wonky, it looks like it's not fully seating at the bottom so I don't trust it. And after that, should I just stick with the Service Manual amount and refill it with that.

Like when I drain the oil later, how much would you suspect is still trapped in the engine after I remove the used filter.

 

[BuickGN]

Originally Posted By: 1993_VG30E_GXE
Basically Buick, to do the initial fill after my overhaul, should I just put in the amount in the service manual WITH oil filter change?

My dipstick is wonky, it looks like it's not fully seating at the bottom so I don't trust it. And after that, should I just stick with the Service Manual amount and refill it with that.

Like when I drain the oil later, how much would you suspect is still trapped in the engine after I remove the used filter.


Back when I ran the preluber on the GN, I would drain it until oil stopped coming out of the pan and then hit the preluber which would purge the oil system of oil. I got a good 1-1.5 quarts more out of it but this was including the volume of the oil cooler and lines. I would say at least half a quart is sitting in the engine be it in the heads, oil galleys, crankshaft, etc.

The factory recommended capacity with filter change is a safe bet after the first fill.

I would use an extra 1/2 quart for the first fill.

 

[mechtech2]

Older road racers filled their crankcases a bit high, to help ensure the pic up would not suck air.
Other high performance guys add a bit more because at high revs, a lot more oil could be on the top end, with less in the sump.
The downside is that we may have more windage problems, under some conditions. Having the crank hit the sump oil sucks power.