Dry Sump Oil Pan Design?

[Orphan]

Hey guys,

I have been working a bit more with solidworks of late and had a go at drawing up a basic dry sump oil pan. The question of this thread is how to design the optimum dry sump pan + scraper for a v8 road/race engine with 4 scavange stages (will be for use with 5 stage pumps).

Now as far as I have seen there are only two main designs for a v8 engine. The first of which has the scavange pick ups on the side of the pan with a sloped surface leading to them. The second I have seen more in relation to Ford and GM engines which has a trench down the centre of the pan with the pick ups drawing from that. I would assume this is more for set ups running something less than 4 scavange stages.

On a random note does anyone know what the pan design for modern F1 engines is?

http://i96.photobucket.com/albums/l200/Orphan707/sump_1.jpg

Above is just a basic drawing I did and is the design I am leaning towards - also has provision to bolt on a scraper. I just recived a sump flange drawing from a guy I know so just waiting on a drawing to locate the main caps by and I will do a more realistic drawing which would technically fit the engine (1UZ-FE).

Does anyone have any thoughts on the best design for a dry sump pan? I think I have a basic idea regarding the pan I think more the issue is scraper design, i've seen quite a few different designs some including a steel mesh.

One thing I have been wondering is if it would be a better design to angle the walls of the pick up end inwards towards the scavange point so the oil gets there more directly as well as eliminating it hitting the side wall as it will go straight to the scavange point. This also would in my thinking mean that scavanging would be more effective as there is less area for the oil to ocupie.

http://i96.photobucket.com/albums/l200/Orphan707/curved_pickup_2.jpg

Now that I look back on it the design I used there wasn't very good but you'll get the general idea of what I mean from that picture. As long as the crank clears the angled walls I can't see too much of an issue with something along these lines besides possible oil pooling on the extra top area which could be solved by crank scraper design or sloping the walls down on a 30ish degree angle. Probably not the best idea, just trying to figure out what would work best.

Any thoughts?

http://i96.photobucket.com/albums/l200/Orphan707/honda-k20-dry-sump.jpg

Here is a Honda K20A dry sump pan, it also has the mesh I was refering to. It looks like there is some form of rounded corners to help direct the oil to the pick ups if the oposite side is anything to go by.

Ultimately the engine I want to design a dry sump for is the one pictured below. It has a full bottom end brace that the main cap bolts go through as well as side bolts. The main cap walls on the final sump will obviouly have to clear all the bolt heads and designing a scraper with that brace could prove to be interesting. Not bad for a standard engine, even a forged steel crank. Too bad its not a 180 degree.

http://i162.photobucket.com/albums/t246/unharmonix/rebuild/Bottom End Rebuild/rebuild_bottom_011.jpg

http://i162.photobucket.com/albums/t246/unharmonix/rebuild/Bottom End Rebuild/rebuild_bottom_017.jpg

I just want to get as much info as I can first and have a go designing one around the toyota 1UZ-FE as I have drawings for that then once I'm ready I'll get my VH41/45 scanned. Already got a quote for full bottom end scan as well as intake and exhaust flanges and ports for $1000. Not too bad considering I would probably shoot myself before measuring it all up by hand and putting it into cad.

Any thoughts or info? Thanks guys.

 

[IceStationZebra]

Your bulkheads and girdle appear to be solid. And your oil pan renderings show a continuation of this solid wall. This brings up one a concern with regard to air movement. Consider leaving a port between cylinder pairs to allow air to move front to rear. I remember reading that Chevy messed with this on some LSx race engines.

With regards to the mesh - some people don't mess with the precise fit necessary for a scrapper and only use the mesh. In general I would think that the mesh would cause some portion of the oil to bounce back at the crank/rod assy, but on the other hand it will help to keep the stay in the pan. Obviously it is directional so install it correctly.

With the pan design I favor #2, since it will reduce the amount of oil bouncing back at the crank/rods.

I believe it was Smokey Yunik who ran an engine on the dyno with no oil pan to see where all the oil was coming from!

ISZ

 

[Orphan]

Thanks IceStationZebra. I've thought about your first comment before. My initial thinking was if they are relatively sealed then there would be less turbulence in the crankcase and simply be the two pistons oposing eachother. That said I later realised the pistons aren't exactly oposing in opperation which could lead to some sort of weird pressure varience ie pressure would be going up and down within each chamber. How big do you think the port should be and what kind of design?

I dislike the idea of mesh quite a lot personally but crank scrapers make sense to me. I see mesh as being more useful in a wet sump system to stop oil splashing around and getting back onto the crank. I can't really see the need for the mesh in a dry sump as the system should be good enough to not leave any large amount of oil sitting in the pan to slosh or splash back up. I'm getting the bottom end of this engine 3d scanned so precise measurement isn't really an issue when it comes to the scraper, i'll just have to make sure I allow for any expansion seeing though it shouldn't be much. From what i've seen 1mm clearance seems to be the go.

By #2 do you mean the design with angled walls to the pick up point? I think at the very lease there should be no flat wall on the pick up side besides the pickup itself and the corners should definately be curved but I think the model I did might be slightly too extreme for actual use. The real issue with it for me is oil pooling on top of the extra pan wall area.

http://www.daileyengineering.com/main.h10.jpg

Picture of a pretty normal GM/Ford dry sump pan, it seems no one is too worried about oil sitting on top of the scraper.

I just read up about Smokey Yunik. A 51mpg car that does 0-60 in 5 seconds, not bad at all haha. He doesn't happen to have any literature regarding dry sumps does he?

As for where the oil is coming from as its a DOHC v8 it should only really be coming from the crank + whatever comes off the pistons and down the block walls, is this correct?

 

[tbuelna]

Orphan,

That dry sump pump assembly by Bill Dailey is a nice piece. I did the original development work on that pump design for Nissan's GTP car back in 1989. I stole all the best ideas from Cosworth's DFX Champ Car engine oil pump and John Butera (Mr. Gasket) machined the parts to my specs. After Nissan's GTP effort folded, Bill Dailey took the pump, made some improvements, and began selling them.

Here's where I stole the design from:

Regards,
Terry

 

[dicer]

As a note, if this car is used for both left and right hand turns, you will want pickups on both sides.
Just curious what manufacuter is the engine based on?
Is the block an after market unit?

 

[Orphan]

tbuelna, do you have any comments on who makes the better pumps these days or any pan design tips? I don't like the shape angles of the bill dailey pan but i'm sure it works just as well. I quite like the machined oil lines to the pump, saves having 8+ fittings and lines to leak or get damaged.

Yes this car would be used in both left and right turns but the G forces aren't enough to make pick ups on both sides nessisary in my thinking as the pickups are located on the side of crank rotation so naturally the oil flings down and in this direction. Another consideration is that would require another 4 scavange stages on the other side, and while this might be fine for a race engine I think its a bit overkill and costly for a road engine. I mean the point of a dry sump is to stop oil starvation and with a 7.5L oil resevour I doubt there would ever be any issue. If someone has thoughts on this i'd love to hear just to get another perspective.

I have seen the 8 pickup design on a lot of the newer indy engines and formula one have a similar system two offset pick up points in the bottom of the pan on opposite sides with a seperate scavante pump for each.

The engine is a Nissan VH45DE or VH41DE they are very very similar, same block etc but one runs duplex timing chains and other updates (the 4.1L). The engine in the pics is a completely stock bottom end, the guy just put the 4.5L crank in the 4.1L to bring it out to 4.5 as they share the same bore. They are using them over in new zealand for superstock cars, running built internals, sleeved down to 4L as its a class restriction, carbed and most limited to 9,000-10,000. 550hp out of them so not bad. There are basically no aftermarket parts for them but there are a few places that make them. We are still trying to get more info out of the guys in NZ who build them but they don't like giving away what they have found

http://img225.imageshack.us/my.php?image=sumprevbvl5.jpg

Piccy of a sump pan designed by a guy I met. Its for a 1UZ-FE for use on a reynard open wheeler, was around 580hp out of the 4L toyota v8. Should see the intake on it A very tasty slide throttle set up he designed himself.

 

[tbuelna]

Orphan,

The windage effects caused by the crank webs and rod big ends will be more powerful than anything else in the sump area. So having a sump shape that directs the oil flow towards the scavenge pump inlet is most effective. Racing engines tend to have low ground clearance sumps, so efficient dry sump systems are essential. High speed rotating crank components passing through oil can cause huge windage horsepower losses.

The pressure/scavenge pump volume ratio is also important. High RPM race engines use a scavenge/pressure volume ratio as high a 4:1. This high scavenge ratio ensures a dry sump and also creates a low ambient crankcase pressure, which helps to reduce compression ring flutter at high piston speeds/accelerations.

One of the nice features of that Dailey pump is that it has a mechanical de-aerator for the scavenged oil flow. Air bubbles entrained in the oil is hard on the crank main and rod journal bearings.

Also, make sure that the cylinder head oil drain passages into the sump are not adversely affected by the crank windage.

Regards,
Terry

 

[Orphan]

So stick with the current idea yeah.

Mechanical de-aerator? I've never heard of that before how does it work? I know the resevour is designed to do that, do most new pumps have a de-aerator or just a couple?

One question I have is what kind of pan depth do you think is nessisary? By my thinking I would make it as shallow as possible, so basically whatever size the pickup fittings are. On another forum a guy mentioned they are usually #12, any comments as to preferable fitting size?

THe cylinder head oil drain is definately not something I have looked at yet, i'll see what I can figure out. I can't imagine it being too bad in a modern engine but still.

Any comment on scraper design? As it stands I am just leaning towards a flat 1 or 2mm plate cut to size with an angle on the leading edge of maybe around 60 degrees, will know more once I see the rotating diamiter of the crank.

 

[IceStationZebra]

I have heard of engine builders using seperate head drains. This helps the windage losses because the oil doesn't have to go through the crank first. On a drag, street or round racing car you could get away with drains only on the rear, but a road racing car would almost certainly need drains front and rear.

"How big do you think the port should be and what kind of design?" Sorry I can't help here. Obviously larger opeings will reduce pumping losses. I imagine you could rationalize the opening size based on the volume of air you need for each pair vs. some maximum air speed...but I don't know what this speed would be. I would keep the openings on the side opposite of the pick-up points. This would help keep the air moving throught the openings from aerating the oil. You could even make a gallery that runs the full length of the side, thus you could keep the stiffness in your design while allowing the air to move.

ISZ

 

[tbuelna]

Orphan,

I don't know if a scraper is really all that important, but I suppose it wouldn't hurt either. It's just a piece of sheet metal that doesn't weigh much.

If you really want to use a scraper, just make sure to allow adequate clearance to any rotating parts. Crank webs and rods can move quite a bit, especially with an aluminum block. Make sure to support the scraper well (don't cantilever it too much, because the cyclic impact forces of the oil being slung against it may cause it to vibrate) and make it from a ductile material like mild steel (so that it bends instead of breaking).

As for the depth of your sump, unless you are lowering the engine mounting position in your chassis and need the extra ground clearance, then there is no real benefit to a shallow sump.

Not too many dry sump pumps incorporate a mechanical de-aerator. Most dry sump systems use a device called a "swirl pot" in the dry sump tank. It's just a tangential scavenge discharge inlet to a cylindrical structure in the tank that causes the heavier liquid oil to centrifugally separate from the less dense entrained air.

Regards,
Terry

 

[Orphan]

Thanks for the reply tbuelna,

That swirl pot you posted is how I have seen it done most, oil coming in at an angle and more often then not a drilled out plate to help aid seperation.

I'm going out to my parents house this weekend to help around the place so hopefully when I get back this week i'll actually draw up a new design.

I guess one question about sump depth I have is is there any point having it any deeper than it needs to be? id if i'm using a #12 fitting that + floor + sump flange are the only other real dimensions to its thickness. Are there any other considerations you can think of as why to make it thicker? Lowering the engine is always a positive as well but most have a good 30mm overhang on the transmission bellhousing so there is only so low you can go in many cases.

Be back in a couple of days.