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Oil Pan Baffle

2698 Views 12 Replies 6 Participants Last post by  Gary
I am currently cleaning up an old oil pan to use on my new engine. Boy, is it grungy! Anyway, as I'm looking at it, I'm thinking that a little baffling in the sump couldn't hurt, as I plan to use the car for track days and autoX. Do I need to get fancy, or would just about any type of material to cause sloshing restriction be benificial? Should I just have it tacked into place? I'm thinking of using aluminum strips that I drill with holes down it's lenght. Any ideas?
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I raced with the stock Aluminum pan for about 4 years with no "slosh" problem. BUT, the "windage" does rob HP... about 5HP by some accounts. So if you want to get back the HP, then you will need to build a "windage" tray into the pan. It's about impossible to describe in words... so go to your local speed shop (or maybe on line) and look at some of the SBC oil pans with built in windage trays. Then build one for your engine.

whats a windage tray? And what does it do?
Just an educated guess here... "windage" refers to the air movement caused by the rotating mass of the crank/rods and piston movement. High RPM's can cause the oil in the sump to be blown around and the oil pick up could suck in some air. A "windage tray" would be a baffle in the pan to prevent this.

RallyBob brought a baffeled oil pan to Carlisle a few years back that would keep the oil in the pan during hard cornering and acceleration.

Bob, if you read this, the door is always open for an occasional post. ;)
A windage tray prevents the oil from splashing back up onto the crank. It's not to prevent running the pump dry as with baffles but rather to help reduce the weight of the crank as well as reduce the density of the air the crank is moving through.

To complicate things even more, they also make scrappers that actually scrap the oil off the crank to allow it to drain back into the pan quicker with out the HP loss of the counter weights hitting the liquid.

Oh well, bottom line was that I got in a hurry to get the engine together and didn't build any of them!

Now, how many miles (Break in) do I need to put on this engine before I autoX it? Missed one Sunday, but there's another one May 18th.

A few words on "windage" trays

While your crank is spinning around at a zillion RPM, oil is being flung everywhere. A couple of things happen here. First, the crank whips the oil into a froth. This is bad... it actually creates air bubbles in the oil. Second, the oil creates a greate deal of resistance to the spinning crank. It's kind of like trying to push a boat oar through water (although not as much resistance). It is this second part that "robs" HP. It takes someware around 5 HP to turn the crank through the oil "froth".

So, the solution to this is the "windage" tray. First, the windage tray has "scrapers" built into it to scrape the oil off of the crank. "Scrapers" is actually a bad word for this since they don't actually touch the crank. Rather, they come close to the parts of the crank spinning near the oil pan. (Actually the oil is being flung off of the crank in long "strings".)

So, as you can see, the windage tray has to be close to the crank. With this in mind, think of the windage tray as a flat plate welded to the top area of the oil pan. Now imagine that the flat plate has a lot of holes cut in it so that the oil from above can drain into the bottom of the pan. Lastly cover the holes with a screen (like from a screen door but coarser). This screen is there to de-areate (take the ari bubbles out of) the oil. Lastly, just above the screen, are little "louvers" angled up at the crank. These louvers are the scrapers. As the crank spins by the lip of the louver, oil near the crank is "scraped" away from the crank, down onto the screen, and then drops through the hole to the bottom of the pan.

The word "windage" is almost a "mis-nomer". I think it comes from the idea that the spinning crank (counter weights, rod journals, etc) creates a "wind" spinning around with the crankshaft. Just like the wind behind a semi truck pulls in road side trash after it passes by... the "windage" from the crank pulls in the strings of oil. Hence "windage tray" to eliminate some of it.

(If I had a picture, that would have been a lot easier to explain... I'll take one and get it posted in a few days.)
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Gary... if this keeps up you could be 100% right by the time its all over :)

thanks for the detailed explanations. Now it sounds familiar. I've heard it being talked about before but never new it was refered to as windage.
Here's a page with pictures of windage trays. Unfortunately, no one makes one for an Opel, so us Opel folks have to make our own.

Here's another way of doing a windage tray. On this page, the "tray" is mounted to the engine instead of in the oil pan.

James was also asking about an "oil pan baffle". A baffel is sort of a little box that is built in the area of the oil pickup down in the bottom of the pan. The baffel has one way trap doors so that the oil can flow into the box... and to the pick-up... but not out of the box. The idea is to keep the oil around the pick up during hard corners.

Here's a page with a picture of a "do it yourself" baffle kit. This kit also includes the stuff to increase the volume of the pan with "kick-outs"

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