Reputable links for horsepower from windage tray/crank scraper

[Kevin Johnson]

... Second, I can change my mind about things when someone has the data or a chain of logic that tells me I'm wrong. For example, before I read that 2013 paper, I also thought that the direct effects of the rotating crankshaft are meaningful in a large V8. However, after I read the paper, I contacted the authors, they gave me their data, and walked me thru it on the phone, I had to revise my views pretty significantly.

I thought that I pointed out (some of) the multiple errors in their logic.

Here's a biggie: They mistook elements of a subset of windage trays as defining the superset of all possible windage trays.

I may have made mistakes in extrapolating their findings too far, but I am not aware of any errors or impactful simplifications in the analysis.

For example, as a simplification, they don’t model the conrod big ends. This is a simplification, but given how little volume the conrod big ends displace, it can’t be impactful for the gas flow results. For oil flow results, it could have some impact.

So please elaborate on the errors in that paper.

Hold on a sec. I am busy with some photographs.

[Kevin Johnson]

Jon, it's all a blur. Too fast for the human eye. You just believe you watched it and you saw what you wanted to see.

Keep working on orthogonality and reading comprehension.

Smokey claimed to have seen it through plastic plates on the side of an oil pan, nothing about a strobe.
I have seen windows with oil on them, you can't see much of anything through them.

Let's see what Smokey wrote. I am pretty sure that he had a powerful strobe light at the Best Damn Garage in Town. At least now you know they existed in 1937, right?

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Wow. Just look at the crank scraper in that dry sump.

[Kevin Johnson]

... Second, I can change my mind about things when someone has the data or a chain of logic that tells me I'm wrong. For example, before I read that 2013 paper, I also thought that the direct effects of the rotating crankshaft are meaningful in a large V8. However, after I read the paper, I contacted the authors, they gave me their data, and walked me thru it on the phone, I had to revise my views pretty significantly.

I thought that I pointed out (some of) the multiple errors in their logic.

Here's a biggie: They mistook elements of a subset of windage trays as defining the superset of all possible windage trays.

I may have made mistakes in extrapolating their findings too far, but I am not aware of any errors or impactful simplifications in the analysis.

For example, as a simplification, they don’t model the conrod big ends. This is a simplification, but given how little volume the conrod big ends displace, it can’t be impactful for the gas flow results. For oil flow results, it could have some impact.

So please elaborate on the errors in that paper.

The major one:

The opposite of no windage tray is all possible windage trays. Being charitable, that could be constrained to all possible windage trays that fit this particular engine.

They then model only one particular example of existing windage tray and seem to think that just the three possible configurations of openings in this one particular example are sufficient to address their case.

The extant configuration of windows/holes in the Gen 3 Hemi tray is not considered at all.

Page 2.
When considering the case where there is no
windage tray above the oil level in an engine, there is an
increase in sloshing which leads to more chances of aeration
of oil. At the other extreme, if the oil sump is sealed off from
the crankcase, it will lead to increased pumping losses due to
increase in crankcase pressure. Thus it's important of have
optimized windage tray design so as to allow proper oil
drainage without compromising engine breathing.
-snip-

Page 3.
MODEL PREPARATION
All the surfaces wetted (partially or fully) with engine oil are
assembled together as a first step to form the computational
domain. This include oil pan, oil tube, oil pump (impeller and
housing), engine block, crankshaft, crankshaft bearings,
crankshaft retainer, crankshaft bearing caps, windage tray,
front cover, cylinder head, head gasket, pistons, connecting
rods, camshaft, camshaft bearings, target wheel, camshaft
sprocket, cylinder head cover, and cylinder head cover
gasket. Various parts/components are either simplified or not
included as part of model simplification and these include
connecting rods, bearings, oil pump impeller, oil squitter,
pulleys/chains and valves stem. Figure 1 shows the current
computational domain with windage tray, drainbacks,
counterweights and volume under the pistons.
-snip-


Page 5.
Three different designs of windage tray (shown in figure 5)
are simulated at the same operating conditions to assess the
effectiveness of crankcase breathing in terms of pumping
losses, flow through windage holes and drainbacks.
-snip-

Page 6.
In this
study where three different designs of windage tray are
simulated, flow pattern under the piston at a given crank
angle is almost identical in each case. However, velocity
magnitude differs from one case to another. This difference
can be attributed to different windage tray designs. Design-1
windage tray resulted in higher velocity magnitude under the
piston for any given crank angle. Quantitatively, peak
velocity (under the piston), for design-1 case are higher than
baseline case by almost 20%. In general, higher velocity
magnitude contributes to relatively higher flow restrictions.
Therefore, in this regard, design-1 is expected to result in
higher pumping losses.
-snip-

Page 8.
SUMMARY/CONCLUSIONS
Despite the simplifications, crankcase breathing simulation
provides a wealth of data that helped in detailed analysis of
flow field, both, qualitatively and quantitatively (with one
complementing the other). Multiple objectives were
accomplished through a single set of simulations. For
example, in order to assess the sensitivity of windage holes
(sizing, location and number) on pumping losses, PV work
calculated for each piston clearly identified the design with
least frictional work. Similarly, when assessing the breathing
of crankcase gases through windage holes for different
windage designs, the flow rate through the windage holes as a
function of crank angle gives precise information as to which
bay (of which design) is breathing better. However, breathing
of crankcases gases through windage holes needs to be
coupled with PV work done by pistons before a particular
design is selected.

[SchmidtMotorWorks]

Did he say he used a strobe?
He did say that he used plastic plates to view through.
I don't believe that anything useful could be seen through plastic plates even if he used a strobe.

[Kevin Johnson]

Did he say he used a strobe?
He did say that he used plastic plates to view through.
I don't believe that anything useful could be seen through plastic plates even if he used a strobe.

Ummm...

One of the defining characteristics of professional mechanics is that they are intelligent. They do not try to check the timing on an engine by looking at a timing indicator whirling past at hundreds or thousands of rpm sans a stroboscopic timing light.


http://www.solarglide.com/products/wipe ... ular-wiper Use a lipophobic coating.

[SchmidtMotorWorks]

I built a custom strobe system to view motion of sensors in an intake duct. I am quite familiar with them.

[Kevin Johnson]

dis·in·gen·u·ous
/ˌdisənˈjenyo͞oəs/

adjective
not candid or sincere, typically by pretending that one knows less about something than one really does.
"this journalist was being somewhat disingenuous as well as cynical"
synonyms: dishonest, deceitful, underhand, underhanded, duplicitous, double-dealing, two-faced, dissembling, insincere, false, lying, untruthful, mendacious;

[ptuomov]

The major one:

The opposite of no windage tray is all possible windage trays. Being charitable, that could be constrained to all possible windage trays that fit this particular engine.

They then model only one particular example of existing windage tray and seem to think that just the three possible configurations of openings in this one particular example are sufficient to address their case.

The extant configuration of windows/holes in the Gen 3 Hemi tray is not considered at all.

I don't understand your comment. The windage tray (and it's placement) that is used as the starting point for the experiments is by my understanding the base windage tray for the gen 3 5.7L "Hemi" engine with it's four breathing holes in the active area. Am I mistaken?

[Kevin Johnson]

The shape of a breathing hole is not trivial: ovate or rectangular (or...). Cross-sectional area is not a sufficient discriminant.

[MadBill]

Did he say he used a strobe?
He did say that he used plastic plates to view through.
I don't believe that anything useful could be seen through plastic plates even if he used a strobe.

It's not mentioned in the text that Kevin presented, but elsewhere Smoky wrote that he couldn't see a (bleep) until he moved the light to inside the pan.

[SchmidtMotorWorks]

Did he say he used a strobe?
He did say that he used plastic plates to view through.
I don't believe that anything useful could be seen through plastic plates even if he used a strobe.

It's not mentioned in the text that Kevin presented, but elsewhere Smoky wrote that he couldn't see a (bleep) until he moved the light to inside the pan.

Sounds like it wasn't a strobe light.

I am not hearing anything remotely convincing that this taffy story is anything more than peoples imaginations.

[Kevin Johnson]

Smokey Yunick put a plexiglass window in a chevy oil pan and watched what happened to the oil. I believe he ran it up to around 7000 rpm.
The oil would 'follow' the crank and looked like ropes.
Then he designed a windage tray for it and that took care of that.
He also used plexiglass valve covers and a variable strobe light to watch and photograph what was going on at various rpms like valve float.

Five and a half years ago.

[Kevin Johnson]

Originally posted by SpoolingWOT
BTW, I wonder how clear of a view that clear sided oil pan gave while the motor was spinning at 7500 rpm?

A number of people *have* actually put plastic windows and stroboscopic lights in the side of oil pans to observe how oil behaves in an operating engine. The windage cloud observed looks like taffy wrapped around the crank. The Shelby turbo guys have told me that one of the Chrysler engineers used to make custom oil pans (back in the 1980s). He brought an engine display with him to car meets so that people could see the effects of scrapers and windage trays -- apparently it was a very dramatic presentation. I know that Smokey Yunick did the same sort of thing when he was trying to develop wet sump pans and pickup tubes for road racing (he was a very famous Chevy small block race engine builder who ran the tech column for Circle Track before he passed away -- he actually did development work for Chevy).

Oh, and the SRT 2.4 has a crank scraper on it as well.


(Answered my own question, I get a tree:tree: )

Sounds like Ed Peters.

[SchmidtMotorWorks]

Originally posted by SpoolingWOT
BTW, I wonder how clear of a view that clear sided oil pan gave while the motor was spinning at 7500 rpm?

A number of people *have* actually put plastic windows and stroboscopic lights in the side of oil pans to observe how oil behaves in an operating engine. The windage cloud observed looks like taffy wrapped around the crank. The Shelby turbo guys have told me that one of the Chrysler engineers used to make custom oil pans (back in the 1980s). He brought an engine display with him to car meets so that people could see the effects of scrapers and windage trays -- apparently it was a very dramatic presentation. I know that Smokey Yunick did the same sort of thing when he was trying to develop wet sump pans and pickup tubes for road racing (he was a very famous Chevy small block race engine builder who ran the tech column for Circle Track before he passed away -- he actually did development work for Chevy).

Oh, and the SRT 2.4 has a crank scraper on it as well.


(Answered my own question, I get a tree:tree: )

Sounds like Ed Peters.

Just like UFO's the sightings decline after mobile phones with video cameras become common.

[Kevin Johnson]

...
Just like UFO's the sightings decline after mobile phones with video cameras become common.

Meh.

Thank goodness: now when a fireball passes over there are usually hundreds of reports and multiple videos.

Windage is accepted science now. It is quite an amount of trouble to rig up an engine like this. As I mentioned, many reports from people that saw videos while in technical programs several decades ago. You yourself saw a film clip from the 1930s.

My high school had an automotive trade program 40 plus years ago. That's gone now. So is drivers ed.

Another example: 87 years ago the Ford V8 was new and exciting. Cutaway engines were interesting. That film also discusses the baffling that was needed in the oil pan to combat oil surging. The engine of choice for Clyde Barrow. [Engine below is a straight six for a truck]
https://www.youtube.com/watch?v=3RB3z1er9Sw

Screenshot_2019-05-31 1932 - The Invention of the Ford V8 Engine - YouTube.jpg