Reputable links for horsepower from windage tray/crank scraper

[dhidaka]

Other than the Ishihara-Johnson site, where can we send him to read up on what to reasonably expect from a windage tray and crank scraper?

Maybe you will find something useful here:


https://www.collectionscanada.gc.ca/obj ... A-5208.pdf

[Kevin Johnson]

To add to his citations: 1994, SAE paper 940792 from FEV Motorentechnik, Aachen. There are also a couple of MIT Theses that explore the V6 Duratec.

Porsche did the original engineering on the Duratec 2.5 engine which you will pick up on if you study enough Porsche design work. The engine sump and windage control was modified by three additional OEMs for their own use: Ford, Jaguar and Mazda. It is interesting to compare the philosophies of the companies involved.

In addition to doing CFD studies, it is important to examine the oil witness marks on well-used engine parts to get an idea of what the suspended oil is actually doing versus what the modeling predicts that it is doing.

If you follow the development of engine families over decades you can see windage control technology being employed as it wends its way through the various design groups.

[pamotorman]

scraper and windage tray on LS engines and you can bet GM put a lot of dyno time on this setup

[ptuomov]

scraper and windage tray on LS engines and you can bet GM put a lot of dyno time on this setup

They won’t put those things in for no reason.

However, I think the question in this thread is whether it’s there to make more power on a dyno or to make the engine more reliable in actual use.

[Kevin Johnson]

Second hand from a racing group that spoke with GM engineers, removing the tray cost about 8 hp.

[digger]

so a windage tray and scraper perform different functions. so which should be used and when? or do both?

[ptuomov]

Second hand from a racing group that spoke with GM engineers, removing the tray cost about 8 hp.

I spoke to a Chrysler engineer about related topics. They have all sorts of simulation models for this nowadays, but the strategy seems to be (my interpretation) to keep increasing the drain/breathing hole size in the windage tray until the power comes back up to the level where it was without the tray.

Of course then in practical use the engine with the tray is in many ways better, including more reliable, etc.

[ptuomov]

so a windage tray and scraper perform different functions. so which should be used and when? or do both?

I’m going to go on a limb here with my opinion: you don’t see car factories putting scrapers in large displacement cross-plane V8s. They do all have windage trays now, however.

[Kevin Johnson]

A lot of times people do not recognize when scrapers and trays are blended together. Louvers are more obvious but the edges of the openings in the Hemi tray below serve that function. There are so many patents for this sort of thing that an OEM needs to tread carefully. NUMEROUS other examples. Examining existing technology is time consuming. OEMs are usually trying to reduce the number of components and costs.

[Jeff Lee]

What has not been addressed; is there a need for either a windage tray and / or scrapper when using a (drag only) big box, limited (or no) sump oil pan. One that only has a few inches of oil at any one time at the bottom?

[Kevin Johnson]

Picture please -- some potential elements of pan design can be considered defacto trays.

[gunt]

sorry kevin , i thought the duratec from ford was robbed from mazda

[ptuomov]

A lot of times people do not recognize when scrapers and trays are blended together. Louvers are more obvious but the edges of the openings in the Hemi tray below serve that function. There are so many patents for this sort of thing that an OEM needs to tread carefully. NUMEROUS other examples. Examining existing technology is time consuming. OEMs are usually trying to reduce the number of components and costs.

To me (and this is an opinion) that Chrysler windage tray is 100% a windage tray and 0% a crank scraper. I judge this based on my personal definition that it’s not a scraper unless it comes close to the volume swept by the rotating assembly.

[Kevin Johnson]

...
To me (and this is an opinion) that Chrysler windage tray is 100% a windage tray and 0% a crank scraper. I judge this based on my personal definition that it’s not a scraper unless it comes close to the volume swept by the rotating assembly.

Different OEMs have different design manuals to guide their engineers. When I was at the Chrysler tech center looking at engines, the dedicated Viper V10 scraper was a full .120" away from the rods (closest approach). Moreover, the juxtaposition of the then new Hemi tray to the extant V6 one was instructive.

[ptuomov]

Instructive as in none of the factory V8 windage trays come anywhere close to the crank or the rods.