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windage tray

Posted: Sun Jan 07, 2018 11:23 am
by sjre
This might be a strange question, but has anyone seen a hp loss on a bbc 4.25 stroke with a windage tray ?

Re: windage tray

Posted: Sun Jan 07, 2018 11:35 am
by ptuomov
sjre wrote: Sun Jan 07, 2018 11:23 am This might be a strange question, but has anyone seen a hp loss on a bbc 4.25 stroke with a windage tray ?
No experience with that specific engine, but it’s known by car factories that some windage trays cost a lot of power in V8s. The power loss comes from the piston pumping inside the crankcase taking more work because the windage tray blocks the gas flow. What the car factories do is they put very large holes on the one side of the windage tray. This recovers most of the power. There’s a Chrysler SAE paper on this whole thing, forgot the name and number.

This sort of holes:

Image

Re: windage tray

Posted: Sun Jan 07, 2018 11:36 am
by bigjoe1
I have never seen that, BUT, the biggest gain I have ever seen was by draining one or two quarts OUT of the pan.



JOE SHERMAN RACING

Re: windage tray

Posted: Sun Jan 07, 2018 12:08 pm
by sjre
Thanks guys i have seen this twice now with a milodon tray on a bbc and a factory tray on a big block mopar????????????

Re: windage tray

Posted: Sun Jan 07, 2018 12:28 pm
by Alan Roehrich
Usually, if adding a properly designed windage tray causes a loss in power, something else is wrong. Milodon's stuff is pretty sound. Those guys are actually racers and hot rodders, who have been in the business hands on, for decades. Call them, ask for help and advice.

Re: windage tray

Posted: Sun Jan 07, 2018 12:37 pm
by BigBlockMopar
How much loss are we talking about here?
Wasn't the purpose of a windage tray to actually free-up power?

Can imagine that the 'caught oil' on top of a windage tray could be whipped up again if not drained quick enough.
I've always punched a number of holes along the direction of the crankshaft's rotation to help get rid of the oil quicker back down into the oil pan.

Although I would *think* a simple steelmesh 'pan' with some reinforcing ribs would be more beneficial actually.

Re: windage tray

Posted: Sun Jan 07, 2018 12:44 pm
by ptuomov

Re: windage tray

Posted: Sun Jan 07, 2018 1:00 pm
by sjre
bbc milidon louvered tray,mopar perf tray. I did not cut any holes in either but did definitely see loss . Between 10 to 20 hp depending.I am not putting down milodon or anyone just saw what I saw.

Re: windage tray

Posted: Sun Jan 07, 2018 1:04 pm
by BigBlockMopar
Interesting.
As a result of the SAE paper I found a downloadable PDF thesis online here from a fellow who worked as an intern at Chrysler about a year later:
https://www.google.nl/url?sa=t&rct=j&q= ... G6LMdsVMyZ

Re: windage tray

Posted: Sun Jan 07, 2018 7:44 pm
by BOOT
My view on trays is with some you may lose dyno hp but you always gain oil control and that can mean better in the vehicle performance.

Re: windage tray

Posted: Sun Jan 07, 2018 7:57 pm
by Newold1
I am not sure how much actual power could be lost with an badly installed or designed SUMP WINDAGE DEVICE, but i am pretty sure its possible and it certainly can play havoc with oil in the sump and pan and that could lead to catastrophic engine damage. Almost all engine sumps can be different from the size of crank throws, stroke, pan size and configuration and windage conditions. I think this means that a tray may not always be the answer, as it may take a windage screen or louvered tray or baffles to eliminate the possible losses or disruptions in the pan and sump. I have seen very few engines today that don't incorporate some form of windage control in the sump.

Re: windage tray

Posted: Mon Jan 08, 2018 7:43 am
by ptuomov
Newold1 wrote: Sun Jan 07, 2018 7:57 pmI am not sure how much actual power could be lost with an badly installed or designed SUMP WINDAGE DEVICE, but i am pretty sure its possible and it certainly can play havoc with oil in the sump and pan and that could lead to catastrophic engine damage. Almost all engine sumps can be different from the size of crank throws, stroke, pan size and configuration and windage conditions. I think this means that a tray may not always be the answer, as it may take a windage screen or louvered tray or baffles to eliminate the possible losses or disruptions in the pan and sump. I have seen very few engines today that don't incorporate some form of windage control in the sump.
My thinking is that if you run the engine one a stationary dyno for a short pull, in most cases with a cross-plane V8 a windage tray will lose some power compared to no windage tray. Why wouldn't the windage tray lose power, its adding to the crankcase pumping work that engine needs to do. With the engine in a stationary position, separating the oil in the sump from the crankshaft usually isn't an important issue to worry about.

The purpose of the windage tray is to make the engine work better when it has been subjected to various external g-forces for a while in actual use. Like oil pans, I think windage trays should be evaluated in their actual use.

If you want to dyno test a windage tray, I think you need a dyno like this:

https://www.youtube.com/watch?v=mfuleS9rnzc

Somehow I have the sneaking suspicion that dyno time on that sort of dyno is a bit pricier than on the usual stationary dyno...

Re: windage tray

Posted: Mon Jan 08, 2018 10:18 am
by Newold1
Obviously you feel that if most engines are sitting absolutely stationary they do whip up windage in the pan and sump areas so its only when the engine starts movement and experiences directional changes in oil dispersion that it would experience power loss. Just take a look at the videos taken on engines with see in windows on their pan when they were on test stands or dynos. I think you might think differently ?

I would say that windage losses don't seem to be as important as the other potential issues like oil starvation, excess oil consumption and damages from aeration of oil. Are there losses in some engines from not controlling windage properly. You bet, but not as much as some seem to think. JMHO

Re: windage tray

Posted: Mon Jan 08, 2018 10:48 am
by ptuomov
Newold1 wrote: Mon Jan 08, 2018 10:18 am Obviously you feel that if most engines are sitting absolutely stationary they do whip up windage in the pan and sump areas so its only when the engine starts movement and experiences directional changes in oil dispersion that it would experience power loss. Just take a look at the videos taken on engines with see in windows on their pan when they were on test stands or dynos. I think you might think differently ?

I would say that windage losses don't seem to be as important as the other potential issues like oil starvation, excess oil consumption and damages from aeration of oil. Are there losses in some engines from not controlling windage properly. You bet, but not as much as some seem to think. JMHO
These are indeed just my beliefs and not facts.

I believe that those videos taken thru plexiglass windows aren’t very informative. This is because human eye can’t tell whether there is a lot of oil in the air or little oil in the air in terms of mass and density. It looks like there’s a lot of oil in the crankcase gas no matter what the truth is.

It also visually looks like the oil is hanging on the crankshaft when that not what I’d happening in terms of physics. In terms of what’s actually happening, I believe the oil is sprayed immediately off the crankshaft and some fraction of the time the droplets rebound back to the crank.

Piston pumping pulses are a first order issue in a large displacement crossplane V8. They have oiling implications, but I believe that during a short stationary dyno pull the crankcase gas pumping losses are much larger deal than anything related to oil moving in an undesirable way.

Once you actually use the engine in a car or a boat, of course the situation is completely different from short pull on a stationary dyno.

Again, these are not undisputed facts. Just my current beliefs.

Re: windage tray

Posted: Mon Jan 08, 2018 11:27 am
by sjre
ptuomov, I believe like you .Also if you can cut the tray as shown instead of holes ,inhalf longways so as to shear the windage and keep it seperated it probably would work better.When you are using a louvered tray, expecting oil to drain and not bounce back up when its a 1/2 in. away from counterweights at 6000 rpm I just dont think its going to happen.