To Deep sump or not to Deep sump

[TheRookie]

Hi Guys

Having a chat to a friend about deep sumps

In his opinion it just a mechanism to hold more oil and that's it

Many claim oil runs cooler with sump but what happens when all the oil is at operating temp.

What your views on this

[58 Plastic Tub]

It's a place to hold more oil (and in the case of oil capacity, more is more).

It's not an oil cooler. If you want an oil cooler, get an oil cooler.

The added capacity only means that the oil takes longer to come up to temperature -- once it's there, it's there.
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Stan Galat
"A single point in isolation is a reference point. Two points is a line. Three points is a trend. Trends don't lie."

[Glenn]

^^^^^
What he said.

Longer to heat up and cool down. More stable temps.

More oil can't hurt.
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Glenn
74 Beetle Specs | 74 Beetle Restoration | 2180cc Engine
"You may not get what you pay for, but you always pay for what you get"

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[bedlamite]

Oil starvation is less likely in hard cornering.
More likely to hit that rock ...

[Glenn]

[jpaull]

More oil means more heat dissipation. The oil is never "all the same temp as the engine". At different spots its different temperatures. Check your oil temp at the sump vs at your pressure sender area. The oil is consistantly different at many areas.

Circulating more "different" oil through the cooler will have a heat dissipation advantage.
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[daveblank]

More oil capacity is always a good thing. I would think that the new sump hanging below the engine would catch some air & offer some heat dissipation/cooling, how much I don't know but in theory it should.

[Alstrup]

[arminyack]

keep the oil level at the lower dipstick mark instead of the upper....reduce crankcase pressure with larger motors?

[oprn]

I would be interesting to poll those that claim a temperature advantage with an added sump. My guess is that they also mount their temperature sender in that sump. If you think about the way the oil circulates (or not!) it makes sense that the corners of the sump where you would put a sensor would be cooler.

The hot thin oil comes down out of the engine right beside the pickup tube is going to get sucked up by the oil pump way easier than the cold viscus oil in the far corners. The slipstream of air under the car is going to keep those corners cooler too.

We added a deep sump to the '69 Bay window Bus and it did not change the oil temperature at all but then the sensor was on the oil filter base not on the sump.

Yes the added oil volume is not a bad thing. Good insurance on tight curves, steep slopes and side hills and can extend your oil change intervals.
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Our cars get old, we get old but driving an old VW never gets old!

[Glenn]

More oil is just a larger hear sink.

My sender is in the filter base also.
_________________
Glenn
74 Beetle Specs | 74 Beetle Restoration | 2180cc Engine
"You may not get what you pay for, but you always pay for what you get"

Member #1009

#BlueSquare

עַם יִשְׂרָאֵל חַי

[58 Plastic Tub]

The OP had a question about which fork to use first at dinner, and we're all telling him how forks are made, what grade of stainless steel is commonly used in forks, and the history of flatware in the western hemisphere. He was asking if an extended sump would reduce his oil temperature in a meaningful way -- not if it's theoretically possible that an extended sump might make a difference of a degree or two in the absolute. We're all posturing here, flexing our engineering chops for each other.

I'll grant that it's possible that adding an extended sump could make a very small difference in peak absolute oil temperature (because of the increased surface area), but the reduction would be minimal to the point of being de minimis. The only surefire way to reject a meaningful amount more heat from the oil and cool it appreciably is with another or a bigger oil cooler.

An extended sump is a reservoir for more oil. That is its purpose. If you have a deeper sump, you can run a lower oil level in the case, thereby reducing windage. Reducing windage has much more potential to reduce the temperature than a chunk of thick aluminum hanging down an extra 1-1/2".

Also, the idea that oil is lazily moving through the engine like a river of molasses is kind of silly -- even the smallest oil pump moves a LOT of oil. There's a hurricane of oil being thrown everywhere inside the case, oil spraying everywhere. Oil is in the bearings (hopefully), up in the heads, and hopefully down in the bottom of the case covering the pickup tube so that it's not sucking air.

More is more in the case of oil -- the stock 2-1/2 quarts is nowhere near enough to make sure that the pickup is always submersed, especially if the car is driven in a sporting manner. Not using an extended sump is playing with fire.

I try to keep things simple when I can. I feel like if an engine has a remote filter, it needs an extended sump (and I can't understand why you WOULDN'T run a remote filter). If it's modified in any way, I'd run a remote oil cooler. I've never understood why there's so much resistance to just doing stuff that we know will help and cannot hurt in any possible way.
_________________
Stan Galat
"A single point in isolation is a reference point. Two points is a line. Three points is a trend. Trends don't lie."

[Glenn]

[BFB]

[oprn]

[EVfun]

[58 Plastic Tub]

[oprn]

A high engine/oil temperature has never ever left me high and dry far from home or close to home for that matter. The driver is in total control of temperature with his right foot. If it starts to get dicey... just back off a bit. 5 mph less can make for a 10* to 15* drop in oil temperature.

This comes from many years of driving a Bay window Bus with a 1600 SP. If any engine is ever going to get hot, that is the one! And like I said before the addition of the deep sump did not change that.
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[TheRookie]

Wow Guys

Awesome responses and perspectives

One that caught my eye was build for the worse case scenario. This guy will pop up some time or other .

[94touring]

It's been a few years so I don't remember exactly, but in my bus under a certain speed, 45mph or something, I didn't even need an oil cooler. However over about 65mph I need more than a stock cooler. I went with the biggest one I could fit underneath because when I am in extreme scenarios I don't want to worry about it. I'm not always on a flat grade, no wind, in 80 degree weather with an empty load.