windage tray

General engine tech -- Drag Racing to Circle Track

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ptuomov
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Re: windage tray

Post by ptuomov » Wed Jan 10, 2018 4:03 pm

bigblockmopar wrote:
Wed Jan 10, 2018 3:08 pm
How about maybe that windage trays on modern days engine are installed closer to the crankshaft than on older engines? Or larger internal block webbing? Providing less room for air displacement/movement between cylinders.

Another thought; how about the thicker oils used in the older engines would show more benefit with a tray in draining/keeping the oil away from the crank than on modern engines with thinner oils.

Then again, why would modern manufacturers spend the resources to design and fabricate something that will limit its engine power.
There must be more (economy/efficiency?) benefits at the lower rpms that offset a little loss in the upper ranges I would think.
I think that a well-designed windage tray definitely has a real benefit in a wet-sump car engine when the car is in actual use. There's a reason why car manufacturers create these complex and expensive-to-manufacture trays. They aren't doing it for fun.

The external g-forces cause the oil to splash out of the sump. The windage tray acts as physical blocker keeping most of the oil out of the rotating crankshaft. You really don't want the oil to surge into the crankshaft, say, when braking into a corner.

The V8 windage trays also usually have devices that shield the head oil drains from piston pumping pulses that disturb oil drain. It's not an effect that one will notice in a 9-second dyno pull, but run the car hard on a track or twisty road for an hour and there's a difference in oil drain and oil aeration.

The block webs and skirts coming further down in newer engines are definitely another issue. The modern, very stiff blocks with main girdles instead of main caps and deep skirts dramatically reduce the area that is naturally available for piston pumping pulses to communicate between bays. In fact, the designed now usually accept the fact that some fraction of the bay to bay pumping gas flows are going to communicate in the valve cover cavities, via the head oil drains. All of this makes it harder to design a windage tray that doesn't increase crankcase pumping losses and reduce power. These modern engines need big breathing holes in the main webs and in the windage tray.

My opinion (not a fact) that modern V8's get a real and meaningful reliability benefit from well-designed windage trays in actual use and possibly a real and meaningful power benefit in actual use by keeping the oil from sloshing into the crankshaft because of the external g forces. My opinion is that most of those well designed trays aren't helping and may be slightly hurting power when the power is measured using a short pull on a stationary dyno.
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Re: windage tray

Post by pdq67 » Wed Jan 10, 2018 9:55 pm

I finally got around to reading this thread!

A lot of good info.

Now if I was worried about this, I would make the front part of my frame such that I could install a deep open, "shoebox", type oil pan that would allow the spun off oil to just go DOWN!

And I would have the normal or whatever flaps and doors to guide the oil and keep it around the oil pump pickup as needed for spirited road-race type driving.

Am I missing anything here unless it is that my vehicle is so low to the ground that I can't fit a deep sump oil pan! Then I would have to rethink everything like is being done here.

pdq67

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Re: windage tray

Post by MTENGINES » Wed Jan 10, 2018 10:04 pm

pdq67 wrote:
Wed Jan 10, 2018 9:55 pm
I finally got around to reading this thread!

A lot of good info.

Now if I was worried about this, I would make the front part of my frame such that I could install a deep open, "shoebox", type oil pan that would allow the spun off oil to just go DOWN!

And I would have the normal or whatever flaps and doors to guide the oil and keep it around the oil pump pickup as needed for spirited road-race type driving.

Am I missing anything here unless it is that my vehicle is so low to the ground that I can't fit a deep sump oil pan! Then I would have to rethink everything like is being done here.

pdq67
A wide pan will do more than a deep pan.

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Re: windage tray

Post by SupStk » Wed Jan 10, 2018 11:12 pm

Kinda late joining this party.
Read an interview with Bill Jenkins years ago, where he said there is 60 hp in the pan. At the time they were discussing small block Pro Stock engines.
Since I just was getting into NHRA Super Stock I was keen on finding my missing 60 horses. There is power to be had on the dyno and more in a car running down the strip.
It isn't a one part fix but a combination of trays, screens, scrappers, baffles, vanes and other oil pan features.
If a person don't look for it, you will never find the power in the pan. By the way I haven't found the full 60 yet.
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Re: windage tray

Post by ptuomov » Thu Jan 11, 2018 8:04 am

MTENGINES wrote:
Wed Jan 10, 2018 10:04 pm
A wide pan will do more than a deep pan.
I would think that a lot of volume under the bays and between the bays would be the most important thing to making power on a stationary dyno, just the most volume one can get. I can see how widening the pan with a kickout on one side will help trap the oil, much like where the holes are on modern factory windage tray.

My question would be that if you have a very large volume oil pan with that kickout one side, would an additional windage tray add to power on a stationary dyno? And if it would, why?
[b]Paradigms often shift without the clutch[/b] -- [url]https://www.youtube.com/watch?v=cxn-LxwsrnU[/url]

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Re: windage tray

Post by pamotorman » Thu Jan 11, 2018 8:25 am

MTENGINES wrote:
Wed Jan 10, 2018 10:04 pm
pdq67 wrote:
Wed Jan 10, 2018 9:55 pm
I finally got around to reading this thread!

A lot of good info.

Now if I was worried about this, I would make the front part of my frame such that I could install a deep open, "shoebox", type oil pan that would allow the spun off oil to just go DOWN!

And I would have the normal or whatever flaps and doors to guide the oil and keep it around the oil pump pickup as needed for spirited road-race type driving.

Am I missing anything here unless it is that my vehicle is so low to the ground that I can't fit a deep sump oil pan! Then I would have to rethink everything like is being done here.

pdq67
A wide pan will do more than a deep pan.
that is why NASCAR has a pan width rule.

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Re: windage tray

Post by Newold1 » Thu Jan 11, 2018 8:37 am

Putomov

What you appear to be saying is that oil pan baffles and windage tray scrapers don't seem to be important on stationary engines such as when they are on a dyno , etc.

My argument for that idea is that if you look at a very recent GM 8.1L Vortec engine there seems to be contradiction to that idea.
This engine was produced as both a truck, industrial and marine versions and if you look at the images I've attached you will see that GM made sure this engine especially in the industrial stationary versions where it was used and is used today in nearly millions of uses i equipped with a very deep full length pan with both scraper trays and lower oil pan baffles to separate oil from the rotating assemblies even when the engine was remaining stainary and in most uses in continuous moderately low rpms. I am sure GM did extensive testing and measurements to make sure this type of oil control was very important even when the engine is aALWAYS stationary for thousands of ours of continuous use?
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industrial-mobile-81L-2.jpg
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Re: windage tray

Post by ptuomov » Thu Jan 11, 2018 8:57 am

Newold1 wrote:
Thu Jan 11, 2018 8:37 am
Putomov

What you appear to be saying is that oil pan baffles and windage tray scrapers don't seem to be important on stationary engines such as when they are on a dyno , etc.

My argument for that idea is that if you look at a very recent GM 8.1L Vortec engine there seems to be contradiction to that idea.
This engine was produced as both a truck, industrial and marine versions and if you look at the images I've attached you will see that GM made sure this engine especially in the industrial stationary versions where it was used and is used today in nearly millions of uses i equipped with a very deep full length pan with both scraper trays and lower oil pan baffles to separate oil from the rotating assemblies even when the engine was remaining stainary and in most uses in continuous moderately low rpms. I am sure GM did extensive testing and measurements to make sure this type of oil control was very important even when the engine is aALWAYS stationary for thousands of ours of continuous use?download.jpg881653_4_site.jpgindustrial-mobile-81L-2.jpg
I was specifically talking about a short dyno pull on a regular engine dyno. If the engine runs for a very long time, I can see the windage tray having benefits for the oil even in a stationary engine. I am not sure if there's a power benefit, but blocking the piston pumping pulses from blowing air into the oil inside the sump will help with reliability. The windage tray will by my guess allow the air to separate from oil quicker in the sump.

Is this the tray you refer to?

Chevy81WindageTray.jpg

If it is, this tray is for an engine that is not just for stationary engines but also for trucks and boats, as you say. Boat engines in particular can bounce off a lot, and one would definitely want to have a windage tray in a wet sump boat engine keeping the oil from sloshing from the pan into the crankshaft. To the extent that this engine is used for multiple purposes, I can see why they would keep it identical or nearly identical between truck, boat, and stationary use even if the stationary use wouldn't really need a windage tray. Just one possibility.

A second thing to note about that tray is that it doesn't (appear to an untrained eye) have any scraper devices close to the rotating assembly. Certainly not mm's away.

In fact, the distance between the crankshaft and the tray looks pretty long to my untrained eyes. This means to me that there's ample room for piston pumping pulses to communicate between the bays without large holes in the tray. Those large-holed trays, like the Chrysler new Hemi trays, are bolted close to the crankshaft and the block has limited breathing space.
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[b]Paradigms often shift without the clutch[/b] -- [url]https://www.youtube.com/watch?v=cxn-LxwsrnU[/url]

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Re: windage tray

Post by Ken_Parkman » Wed Jan 17, 2018 4:53 pm

Late to this discussion, but to add a few comments. There is some serious weirdness that can happen in an engine sump. It is not intuitive on what is going on, and to explain where the power is going you have to revert to fundamental physics. The potential power loss in a sump is huge and it does depend on oil control, even in a stationary engine. The issues relate to 2-phase flow.

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Re: windage tray

Post by Newold1 » Wed Jan 17, 2018 5:52 pm

Ken

Would you please explain the physics of two phase oil flow and how it relates to power losses in an oil pan?

Thank You

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Re: windage tray

Post by BenE64 » Wed Jan 17, 2018 6:48 pm

Newold1 wrote:
Wed Jan 17, 2018 5:52 pm
Ken

Would you please explain the physics of two phase oil flow and how it relates to power losses in an oil pan?

Thank You
What he said! :mrgreen:

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Re: windage tray

Post by Ken_Parkman » Wed Jan 17, 2018 7:56 pm

I could not even begin to explain the physics of 2 phase flow! That's a whole sub science of fluid mechanics.

But a couple thoughts are the 2 phase mixture of air and oil could be closer to one end or the other. And the drag effects are wildly different depending on which end you are closer to. Another really deep thought is the constituents of the phases can have a significant effect on the mach number - not the speed. And if the mach number gets driven closer to the speed of the assembly the drag effects multiply. But I'm still trying to get my head around that one, don't have it figured out.

It seems it's a real good idea to try to get the flow phase much closer to the air.

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Re: windage tray

Post by In-Tech » Wed Jan 17, 2018 8:07 pm

Study the concept inside a GM computer where aeration is considered.
Heat is energy, energy is horsepower...but you gotta control the heat.
-Carl

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Re: windage tray

Post by MadBill » Wed Jan 17, 2018 9:56 pm

Ken_Parkman wrote:
Wed Jan 17, 2018 7:56 pm
... Another really deep thought is the constituents of the phases can have a significant effect on the mach number - not the speed. And if the mach number gets driven closer to the speed of the assembly the drag effects multiply. But I'm still trying to get my head around that one, don't have it figured out...
Can the Mach number really be a concern, given that for example the surface velocity of a 4" radius counterweight turning 8,000 RPM is only ~ 140 ft./sec.?
Felix, qui potuit rerum cognscere causas.

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Re: windage tray

Post by rustbucket79 » Wed Jan 17, 2018 11:53 pm

No amount of trap doors and baffles will maintain oil pressure on a long and hard braking episodes in a full length box oil pan with little or no sump. :wink:

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