Oil pan windage screen

[toolmakeron]

Drag race application, BBC.Wet sump. Awhile ago I thought I saw a post about the pros & cons of a windage screen VS a louvered solid windage pan. My search on here came up short. Does this post subject ring a bell? Thanks guys

[Alan Roehrich]

I quit using the screens, because at the end of every season, no matter who balanced the assembly, or how, I found broken sections of screen in the pan.

[Kevin Johnson]

Screening needs to be supported so that it resists flexing. Studies of oil droplets being ejected show they come in waves correlated with rpm. The waves will excite the screening structure. This is why it needs to be supported. This is independent of assembly imbalance which would certainly be another issue. Another important way the screening can be excited is by the pumping exchange within and between bays.

The smooth metal interior of louvered windage trays allows oil droplets to bounce and be struck by the rotating assembly. This bouncing off of smooth surfaces will occur in dry sumps under full vacuum as well. You can never recover the energy that is lost and when an atmosphere is present, the even smaller droplets produced will lower the rpm level at which air flow will carry or entrain the droplets back into the rotating assembly. If you look at oil witness marks in trays from well used motors you can see the pattern of flow: Honda I4 motors to Chevy V8s'.

An aside: if you examine droplet ejection patterns from rotating assemblies with the oil pan removed, keep in mind that the flow dynamics within a confined volume are different in many ways. Read about the tea-leaf paradox investigated by Einstein -- it was one of his more famous papers (http://en.wikipedia.org/wiki/Tea_leaf_paradox).

Baer's law: In geology, Baer's law, named after Karl Ernst von Baer, hypothesises that, because of the rotation of the earth, in the Northern Hemisphere, erosion occurs mostly on the right banks of rivers and in the Southern Hemisphere on the left banks. In 1926, Albert Einstein wrote a paper explaining the causes of the phenomenon.

Ideally windage trays should be of multiple layers -- at least with the technology that exists today. Screening with small louvers will capture the droplets better and dissipate their impact energy. I would suggest suspending the screening over the tray to allow flow beneath it.

[Alaskaracer]

IMHO, if you have the room, run the deepest pan with the largest kick out you can get, and no windage tray unless it's built into the pan.

[rally]

I like the original factory Chevy Big Block Windage tray where fit works. I have a original factory Chevy BB soild windage tray, semi circular with small holes on the bottom, GM Part number 3879640. These were used in the 1960s era. Bill Jenkins used these with the 6 quart deep sump pan 3879633 in his 67- 68-69 Camaros. I have this windage tray for sale. Shoot me a messgae if interested. This tray is very rare and are hard to find these days. Its a semi circular soild tray with three small holes located on the bottom, a lot like the 69 Z-28 302 Trays which were installed in the 302 motor.

[Dan Timberlake]

Here is some info from a 1966 SAE paper 660742 - "The Coventry Climax racing engine 1961 - 1965 ".
For 1960 the Formula 1 rules chopped displacement from 2.5 to 1.5 liters / 90 cubic inches.

CC went from a 2.5 l 4 cylinder to a 1.5 liter V8. The first few iterations were 181 HP at 8500 rpm with 10.5 to 1 Compression ratio.
195.5 psi BMEP.

the image includes the paragraph describing oil windage problems, and a few details of the "solution."

[Dan Timberlake]

Hi Kevin,

The SAE paper is not explicit when the screen baffle "eventually" appeared, but the Coventry Climax V8 development began in 1960 when the new for 1961 rules were suggested (but resisted by Briish participants unitl late 1960), but were not deemed ready to race until the 1961.
So presumably the basic development, including reduced "oil churning" (which was credited with "sizeable gain" in HP) was complete in 1960.

FWIW Wikipedia says the Triumph six first appeared in 1960. Were they fitted with screen windage tray/baffles from the beginning?

Which series Porsche first used screen baffles?

Seems like Screening baffle/windage trays was maybe mentioned in the mid 70s Jenkins book. I wonder how long he had been using it, and what his inspiration was.