dry sump pump

[Hector]

Originally posted by michaelwaltrip:
Short answer: Dry sumps are not worth the time/effort/weight/complexity when a simple trap-door style oil pan works great for this application.

In that case, nothing in racing is.

Good racing is a matter of millimeters and milliseconds. Maybe it isn't good for some teams, but I'm sure with enough improvements in other areas, going to a dry sump would be your best improvement. Plus, once you get the system designed the first time, it's fairly easy to recycle year after year.

Our pan's a half inch thick. Without frame tabs, the pan bolts are the lowest point on the car. That makes the single heaviest component (besides driver of course) several inches lower. I know our suspension guy appreciates it.

~2g has minimal effect on oil pressure.

~2g has no effect on our oil pressure. Lots of logs to back it up. The pressure vs. rpm histogram line is so well defined it's hard to make out the individual points. Looks like a nice, solid line.

In the end, if you think a dry sump is the best place to invest your efforts, or if you're just damn interested in doing one (this is a learning competition after all) then go for it. I'm all for them. However, when you say something like "We had never had a car running long enough to see the effects of oil starvation" it makes me think that just getting a car running and testing would be time better spent.

[Kevin Dunn]

I'm in total agreement with Hector. The dry sump we've had is proven and has required minimal development over the span of its use.

If I remember, I'll try and have someone snap some photos of our setup when I'm in the lab tomorrow or Saturday.

[Pennyman]

In that case, nothing in racing is.

To quote Pat Clarke, "This isn't racing...this is fun"

It's all about the justification.

[VFR750R]

Many a championship have been won without a dry sump. But the best solution to the problem performance wise, is a dry sump. I've seen pulley driven pumps, oil pump shaft driven pumps, and heard of pumps belt driven off the driveshaft (for vacuum assist only, no pressure sections).

I like the belt driven solution mostly because I don't like the idea of running an electric water pump (this isn't drag racing). But a really smart engineer could have both with some extra design work on the two pumps .

The belt driven solution also allows fine tuning of speed, easier packaging of lines/pump, although some design work will have to go into adding a drive off the end off the crank or cam. Some of these engines have dry flywheels, in which case you can get rid of the flywheel cover all together, those with 'wet' flywheels will require new covers and an oil seal, and then the water pump port option becomes more attractive.

[abinley]

We have run a student designed dry sump for the last 2 years on our 600f4i. We use the factory pump to feed the motor and a single stage to scavenge. We have also used a dual stage when we were turbocharged. The pump is driven off the oil pump shaft, where the water pump normally lives. We use an electric water pump in it's place. The first version of our pump did seize at one point shearing off the tang on the driving shaft. The reason for the failure was the lack of an aligning feature in the pump, which was fixed in the new version with dowel pins. Our new pump has been flawless, and is about the size of a small mandarin orange ha ha! Here is a shoddy pic of the old 2 stage pump:
http://fsae.uvic.ca/gallery/th.../Oil%20Plate%202.JPG

[michaelwaltrip]

Originally posted by poe21:
I realize that there are differing opinions. I appreciate all the information, and I need to do some digging and testing, but I really don't understand why people think that dry sump is failure. I thought I saw several of the top teams running dry sump (I'm pretty sure RIT and one graz school). I also heard from a guy that the new corvettes only run dry sump now. Maybe I was mistaken, but he did come to the car show with a brand new lingenfelter(sp?) corvette. Anyway, I would like to hear more positive and negative experiences from those who have tried dry sump. Also any pictures (I know that they are hiding around here somewhere) would be nice.

PS I am not trying to bash anyone's opinions, just wanted to get some more information about the dry sump system.

This is true.

Several of the top teams do run dry sump. But those teams (usually) bring more people to competition than we have working on our car the whole year.

Back when we used to run a dry sump (05-07), we had many problems. Most of them stemmed from having only about 3 people who knew anything about it. We had a pully driven off the oil pump shaft (in place of the water pump) and our custom-designed pump was housed in the rear box structure. The pump was inefficient, the tank was always a problem (finding places to mount it, running extra oil lines, de-aerating the oil), the pully drive system required near-constant maintenance, and the whole system was about 10 pounds heavier than our current wet-sump system.

I have no pros to report from our system. Maybe other teams have had better experiences, but we just don't have the resources to invest in it. Nearly all of our car failures in those years were a direct result of the dry-sump. At least 4 engine failures (that i know of) plus two endurance failures due to an oil leak and oil starvation.

[RacingManiac]

Not being an engine person and all I can only comment on this based upon my observation of how our(Toronto) system works. When we are running the F4i we run a 2 stage(I believe) dry sump off the waterpump shaft, with custom pump sourced from UK, we also run the stock waterpump inline off the same shaft(imagine layout being [o][o][w]). The issues we've had have more to do with the shaft seal and face seal between the pumps may leak, mostly due to manufacturing tolerances. Most years that we've run the system its been pretty good AFAIK. Dry sump also allows for the chassis designer to place the motor a lot lower to gain some CG advantage. The system is no longer in use in 09 because of the engine switch to 450 single Honda.

If other Toronto guys read this maybe they can chime in...

[Joe the plumber]

Originally posted by VFR750R:
I like the belt driven solution mostly because I don't like the idea of running an electric water pump (this isn't drag racing). But a really smart engineer could have both with some extra design work on the two pumps .

The belt driven solution also allows fine tuning of speed, easier packaging of lines/pump, although some design work will have to go into adding a drive off the end off the crank or cam. Some of these engines have dry flywheels, in which case you can get rid of the flywheel cover all together, those with 'wet' flywheels will require new covers and an oil seal, and then the water pump port option becomes more attractive.

Seems like a lot more work to not run an electric water pump. For the fact of easier packaging maybe but you now have to design new ways of running the pump. We have been really successful with an electric water pump. Oh and Hector you must of had one great oiling system designer if your oil pressure curve is a straight line.

[James Waltman]

I’ve been trying to decide for a few days if I should bother saying anything on this topic.

I guess that this means I will.
First up, we ran a dry sump on our ’04 car. There are topics on here with pictures of it.
We used this logic: Real race cars have dry sump systems, we’re using a motorcycle engine that wasn’t meant to corner like we do (oil starvation will probably be an issue), and we can lower the engine/car CG.

That was enough to get us started – and we didn’t hold back.

How much were we actually starving an engine with the stock oiling system? Dunno.
How much did we actually lower the CG? Dunno.
How much drag (in HP) does the new belt drive system add (a question during the Design event at comp)? Response: “Uhhhhh…..”

It was a very cool system though. And we really did lower the engine.
Then it failed on us at competition. The pump, plumbing, pan, seals, bearings, fittings, and most everything else worked well. It was an oversight on the modification to the crank cover that let the starter’s idler gear go wonky, fail, and ruin the block.
I’m sure we had hours of engine cranking on the dyno and in the car before competition. If we had been able to get two more minutes of cranking it would have lasted us through competition. No luck.
So, it was a system that we inadvertently modified that failed on us.

Originally posted by poe21:
…and have been using a carbon fiber oil pan with no baffeling up to this point. We had never had a car running long enough to see the effects of oil starvation (which I believe we are occasionally seeing).

So, you have an assumption that, on occasion, the engine isn’t getting enough oil but you have no baffles and no data. You’re proposing spending hundreds of hours to solve a problem that you might not actually have (or at least you can’t put numbers to the severity of it).
Same thing we figured.
Some basic baffles are less than 1% of the effort required to do a dry sump and would have a huge part of the benefit.

Wesley outlines the perfect method. Go back and read his post. He describes an engineering approach.

Identify a problem. Put some numbers to it. Set a target. Design, build, test. Achieve the target. Do it with the most efficient use of resources (time, people, weight, cost, etc).

Originally posted by poe21:
Since I am in the department of powertrain, I will focus on my problems at hand.

Finally, about the idea that you should be focusing on the engine while the rest of the car/team is having trouble: it’s wrong.
The point of this is to build a car – not a sweet engine. If they’re having trouble and you’ve got time to think about dry sumps – you should be helping them.
I really like Geoff Pearson’s way of looking at this: “If you are finishing under 800 points you don't have a car problem.”

This isn’t meant to be preachy and I’m not trying to talk you out of it. If the numbers say you need a dry sump you should figure out if you can afford it (in terms of time, people, resources, and money (probably in that order)).

[flavorPacket]

James, good post. BUT, I think you left out the pressing question, "What are you trying to get out of FSAE?" By all means, if the kid wants to learn how to design dry sumps, FSAE is the place to do it.

Second, the original poster is making the most common mistake in FSAE development: trying to do it all in one year. Do yourself a favor and spread the project out. Talk to your chief engineer and get a game plan. Get some newbies ready to take over. Give your system a full summer of testing. THEN, put it on your car.