windage tray

[Newold1]

I feel like other than trap doors baffles my inadequate education in gobbledy gook and double speak that my understanding of the descriptions of 2 phase oil flow movement is a case of , if I can't baffle them with brilliance then I will mystify them with bullshit!

[ptuomov]

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.

It's a funny coincidence that about a year ago I asked a job candidate this same question. He had an engineering degree, and was looking to switch to finance. I asked him how does he model the two-phase flow in the car engine crankcase. Gave a decent answer, at least to the point I could understand it. It's a perk of the job to ask people explain things about their field.

[n2xlr8n]

I'm just shocked that we had a robust discussion of windage without Kevin and Jon.

[Krooser]

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.

How many remember the big Moon breathers we used down low on the block or oil pan 50+ years ago?

[Mattax]

ptuomov,
To answer your question about Chrysler windage trays: numerous publications. This is one from my Mopar Performance handbook, published by Chrysler: 'We ran the B-RB windage tray on our new 440 dyno engine. 400 hp without, 416 hp with tray'. Engine was run to 6000 rpm.

Yes, sometimes. It also has an exception.
Starting with the B & RB Engines as that's what's been referenced. The stock pan is center sump with shallow front and rear.
From (Chapter 5) Mopar Engine Chrysler Corporation, Direct Connection p/n P4349340 1984
With the recommendation to modify Stock Pan by increasing depth of sump by 2" (or purchasing basically the same from Chrysler) the text says stock based pans must have the rear acceleration baffle sealed to sump. Illustration 5-18 states "Include Windage Tray with this Modification!" (in capital letters). So the tray is in addition to the horiontal sump baffle.
Two pages later it states "Every high performance "B" or "RB" engine should have a windage tray." Similar to the quote above, this bulletin then goes on to state "It's worth 15 Hp at 6000 rpm!"
However the same pages note that with the full Race Oil Pan (10" deep rear sump with with swinging pickup, and 6.5" deep front half) the windage tray should not be used. With this race pan "the windage tray should be removed resulting in increased car performance. If the car slows down when the tray is removed, the pan has been compromised too much and the tray should always be used with that particular pan."

So it would seem that the use of the windage tray is, at least in part, related to depth of the pan's return areas and sump. They further clarify this in the chapter on race oiling systems. Specifically stating that if the front portion has to be made shallower in one of the options illustrated, its likely that the windage tray will be needed.

It should also be mentioned that the stock 340 cid smallblock v-8s were equiped with windage trays from the factory. However, there was a bulletin or ? advising racers to open up the louvers, as the exit areas were too small. Sorry I can't find that one quickly.

[Geoff2]

Mattax,
No exception. Direct quote from MP book #4452790, page 316.

[ptuomov]

In an unrelated thread, here’s a windage tray example from pre-computer-everything era:

viewtopic.php?f=1&t=52080&start=15#p713427

Oiling problem in a shallow sump, which gets cured by either 2” deeper pan and no windage tray or a 5/8” deeper pan and windage tray. No word whether the test was under g-forces or not, or whether the screen met or only approached the deep pan power level.

[Kevin Johnson]

Well, if nothing else, it's a widely-held mass delusion, shared by a number of O.E.M.s...

A couple of references:
https://www.google.ca/search?q=OEM+cran ... 45&bih=885

https://www.crank-scrapers.com/

https://www.google.ca/search?q=the+tea+ ... e&ie=UTF-8

Which car factory puts a crank scraper in a modern crossplane V8? I don’t recall seeing any.

Almost all of them have fairly complex and expensive to manufacture windage trays, though. The trays are reasonably far from the crankshaft, and all have generously sized breathing hole area.

Dodge used a crank scraper in the cross-plane V10 in the Viper. I measured the clearance in a Chrysler tech center and the closest approach was about 3mm or .120". I know the different OEMs have differing design manuals for how far away a fixed part should be from the rotating assembly.

Nissan went as close as 1mm with a scraper louver in a baffle plate attached to the bearing beam of an SR20.

[Kevin Johnson]

I have not used one of Ishiharwa-Johnsons scrapers. I have read about them and the teflon wiping technology and it seems to work well. I will have to try one and see for myself. I know that all scrapers definitely seem to work best at certain rpm ranges and I worry that if I tighten scraper to throw clearances any tighter I could end up with metal in engine, a lot of creepy noises, unhappy engine owners and warranty work! With metal to metal possibilities I like the Horse Shoes and Hand Grenades" idea - CLOSE!

The engine in my car has a heavily modified I-J system in it. It does solve a very specific problem with my engine very well. It's not scraping anything off the crankshaft, however.

The system I designed for the Porsche 928 had three separate scraper arrays. The company that copied the design retained them.

[ptuomov]

The engine in my car has a heavily modified I-J system in it. It does solve a very specific problem with my engine very well. It's not scraping anything off the crankshaft, however.

The system I designed for the Porsche 928 had three separate scraper arrays.
The company that copied the design retained them.

"The company that copied the design retained them."

What would you conclude from that, given the company in question?

[Kevin Johnson]

The engine in my car has a heavily modified I-J system in it. It does solve a very specific problem with my engine very well. It's not scraping anything off the crankshaft, however.

The system I designed for the Porsche 928 had three separate scraper arrays.
The company that copied the design retained them.

"The company that copied the design retained them."

What would you conclude from that, given the company in question?

That they were pleased with the performance of the product as were many other companies that copied our designs.

I designed bespoke stroker versions of the system for them for crankshafts they had manufactured. They asked me not to sell those designs to other customers and I never did. I don't make the 928 sets any longer. They consume too much time.

[Kevin Johnson]

ptuomov,
To answer your question about Chrysler windage trays: numerous publications. This is one from my Mopar Performance handbook, published by Chrysler: 'We ran the B-RB windage tray on our new 440 dyno engine. 400 hp without, 416 hp with tray'. Engine was run to 6000 rpm.

Yes, sometimes. It also has an exception.
Starting with the B & RB Engines as that's what's been referenced. The stock pan is center sump with shallow front and rear.
From (Chapter 5) Mopar Engine Chrysler Corporation, Direct Connection p/n P4349340 1984
With the recommendation to modify Stock Pan by increasing depth of sump by 2" (or purchasing basically the same from Chrysler) the text says stock based pans must have the rear acceleration baffle sealed to sump. Illustration 5-18 states "Include Windage Tray with this Modification!" (in capital letters). So the tray is in addition to the horiontal sump baffle.

The B-RB stock windage tray flange was modified by Chrysler to include a trapezoidal shaped baffle that deflected rearward surging oil downward and hindered its entrainment by the final counterweight.

[ptuomov]

That they were pleased with the performance of the product as were many other companies that copied our designs.

That company advertises the scraper system with a "dyno" "data" that isn't from 928 and doesn't satisfy the hp = lbf-ft * rpm / 5250. Everyone is welcome to draw their own conclusions.

[Kevin Johnson]

That they were pleased with the performance of the product as were many other companies that copied our designs.

That company advertises the scraper system with a "dyno" "data" that isn't from 928 and doesn't satisfy the hp = lbf-ft * rpm / 5250. Everyone is welcome to draw their own conclusions.

Yes.

Well, that does confirm the veracity of what I said. They are reposting the dyno data for the SRT4 kit that I put up over 14 years ago.

This is now the third time you have brought it up. Twice in recent Speed-Talk posts and previously many years ago on the Rennlist. My public response has always been the same:

Some visitors have commented that the hp and torque figures in the charts below apparently do not conform to the formula

HP = [TQ X RPM]/5252

There are at least two commonly used hp and torque measurements made by sophisticated dynamometers: inertial and steady state. Often components will show improvements in terms of one versus another. For example, a lightweight flywheel, ceteris paribus (all other things being the same), will likely show an improvement in inertial measurements but not steady state.

The engine that Ed tested was going straight into a race car and like most teams he would not release actual hp and torque charts of the engine. The hp and torque data seen are a combination of results from inertial and steady state measurements; the oil and coolant temperature readings are explicitly from steady state readings. In this way the changes in performance strictly from the addition of the windage tray and scraper assembly can be seen but the proprietary underlying ultimate performance of the engine is still masked from casual inspection.

September 12th, 2005

Ed Peters, retired Chrysler engineer, active racer and owner of Magnum Force Engineering, performed back to back dyno tests today on the Ishihara-Johnson standard steel combination scraper, dual-windage tray and baffle setup for the 2.4 Dodge engine (see pictures below). Magnum Force Engineering has a state of the art environmentally controlled dyno room where, among other parameters, ambient air temperature of 71 degrees Fahrenheit was held to within +/- .5 degrees. Experimental conditions in the dyno room and for the engine were normalized for both back to back pulls.

The tests were run on a normally aspirated 2.4 liter P.T. Cruiser engine with a modified engine management system allowing it to exceed the normal factory redline. The balance shafts in this engine were removed and, notably, it was equipped with the factory oil cooler for the SRT4 and P.T. Cruiser Turbo. The engine was equipped with a 195 degree F thermostat. Five quarts of fresh Mobil 1 10W-40 synthetic oil were used during each pull.

Prior to both pulls, the engine oil pan temperature (oil temperature in the reservoir) and coolant temperatures were allowed to stabilize. At each rpm increment in the tables below the temperatures were allowed to again stabilize in order to give an accurate reflection of the steady state operating conditions in the engine at that speed.

At peak rpms, use of the windage tray setup accompanied a 24 degree Fahrenheit drop in oil temperature, an 11 degree drop in coolant temperature and a 7 hp and 13 ftlb boost in power.

Ed Peters remarked that "this setup is the most significant bolt-on change for oil and windage control that he has witnessed since 1986."

In 1986, while at Chrysler, Ed performed joint research with Mobil Oil on windage losses in the 2.2 Shelby Turbo engine. He developed a performance oil pan that regained 9 hp at 6000 rpm when using Mobil 1 oil. Earlier in his career he was involved with the Dodge Daytona / Plymouth Superbird that dominated NASCAR racing for a period of time.

It is important to note that a turbocharged version of the 2.4 engine would have higher windage losses and oil heating due to the increased level of normal blow-by in the crankcase. Therefore even more benefit would be found in the use of a proper windage control system.

[Kevin Johnson]

In an unrelated thread, here’s a windage tray example from pre-computer-everything era:

viewtopic.php?f=1&t=52080&start=15#p713427

Oiling problem in a shallow sump, which gets cured by either 2” deeper pan and no windage tray or a 5/8” deeper pan and windage tray. No word whether the test was under g-forces or not, or whether the screen met or only approached the deep pan power level.

The SAE paper referenced was from the mid 1960s. (https://www.sae.org/publications/techni ... nt/660742/) The lessons learned were incorporated by Triumph in their straight six sump. More interesting is that over a decade later, Porsche also used a wire gauze screen over the sump in the 928. They even experimented with different mesh sizes (this was in production vehicles mind you).