View Full Version : Dry Sumping... (I know its punny.. oh ha!)
beagley
07-27-2010, 09:02 AM
For any of you that have dry sumpped an engine... how difficult is it? Does it require totally revamping how the engine lubrication system works? I'm interested in making an engine dry sumpped, just because, but I don't want to go over my head. If any of you have pictures and you don't mind, I would appreciate getting to see how the system is all linked together. Thanks in advance!
Beags
if the engine has good clearance between the pavement and the sump, why there is a need to dry sump?
can you explain if there is advantage?
MHKflyer52
07-27-2010, 11:49 AM
if the engine has good clearance between the pavement and the sump, why there is a need to dry sump?
can you explain if there is advantage?
One advantage is the oil is pumped from a source (the reservoir) that is usually much larger than the standard oil pan and there is very little chance of cavitation from cornering (high G loading) as I understand it, another is the pump is usually external of the engine for less engine drag and easier servicing I would suspect but not sure of so don't hold me to that.
BrunnyS1
07-27-2010, 11:57 AM
A dry sump offers many advantages, namely increased oil capacity and a lower center of gravity for the engine. Because the reservoir is external, the oil pan can be much smaller in a dry sump system, allowing the engine to be placed lower in the vehicle; in addition, the external reservoir can be as large as desired, whereas a larger oil pan raises the engine even further. Increased oil capacity by using a larger external reservoir leads to cooler oil. Furthermore, dry sump designs are not susceptible to the oil starvation problems wet sump systems suffer from if the oil sloshes in the oil pan, temporarily uncovering the oil pump pickup tube. Having the pumps external to the engine allows them to be maintained or replaced more easily, as well.
The oil capacity of a dry sump can be as big as you want. The tank holding the oil can be placed anywhere on the vehicle.
In a wet sump, turning, braking and acceleration can cause the oil to pool on one side of the engine. This sloshing can dip the crankshaft into the oil as it turns or uncover the pump's pick-up tube.
Excess oil around the crankshaft in a wet sump can get on the shaft and cut horsepower. Some people claim improvements of as much as 15 horsepower by switching to a dry sump.
(by allowing a lower hoodline).
The disadvantage of the dry sump is the increased weight, complexity and cost from the extra pump and the tank.
One advantage is the oil is pumped from a source (the reservoir) that is usually much larger than the standard oil pan and there is very little chance of cavitation from cornering (high G loading) as I understand it, another is the pump is usually external of the engine for less engine drag and easier servicing I would suspect but not sure of so don't hold me to that.
Thanks
True, it can hold more oil but some wet sump has big oil pan too.
My Esprit holds like 6 quarts.
Cavitation? wet sump is used since we invented the car and perhaps logged in centillion of miles. Morosos design has anti-cavitation slots, feeder grooves and an enlarged bypass area machined into the housing to bleed oil back to the inlet side of the pump.
Wet sump less something to go wrong (simplier).
beagley
07-27-2010, 12:35 PM
How much heavier could a dry sump system be? 20 - 30 lbs at most? I know it depends on the number of pumps that you have installed in the loop. I've tried to upload a picture of how I understand a dry sump to work but I can't access that part of the site... anyway, here is how I see it working:
Reservoir ---> Pump 1 ---> Manifold ---> Engine Block ---> Pump 2 ---> Reservoir
This is probably due to my inexperience with engines, but does this require a manifold type setup so that you run oil to all of the different points of the block or is there just a single access point somwhere and the oil passageways determine where the oil goes, like this?
Reservoir ---> Pump 1 ---> Engine Block ---> Pump 2 ---> Reservoir
Edit: In this case the "manifold" just refers to a way to take in one supply line of oil and have multiple out lines to the engine block.
WestTexasS2K
07-27-2010, 01:54 PM
Dry sumps work with a stacked pump arrangement. Usually you have a pressure section and then suction sections that pick up the oil at different places on the engine. You can have 2, 3 or 4 suction sections depending on your needs. You will have a oil resevoir usually several quarts more than your normal pan holds 8-12 qt is common. You will usually have a oil pressure bypass valve to set your pressure. Then an external oil filter is in a normal set up. You may have to block off engine oil galley where the stock pump feeds into it so it doesnt just dump oil straight to the pan.
There are alot of associated hoses required to plumb all this in.
I wouldn't recommend a dry sump unless you are having oil starvation problems usually only occurs on the race track where your lat Gs are getting up in the 1.5+ range. The Honda engines we use do fine for most tracks, but we have damaged a few engine at Run and Gun due to the banked oval that allows for high G load and engine is turning 7500-8000 rpm. At this engine speed we are pumping alot of oil and can uncover the pump even with it over filled with 6qts.
beagley
07-27-2010, 02:27 PM
Dry sumps work with a stacked pump arrangement. Usually you have a pressure section and then suction sections that pick up the oil at different places on the engine. You can have 2, 3 or 4 suction sections depending on your needs. You will have a oil resevoir usually several quarts more than your normal pan holds 8-12 qt is common. You will usually have a oil pressure bypass valve to set your pressure. Then an external oil filter is in a normal set up. You may have to block off engine oil galley where the stock pump feeds into it so it doesnt just dump oil straight to the pan.
There are alot of associated hoses required to plumb all this in.
So then this http://usa7s.com/vb/picture.php?albumid=18&pictureid=95 is really what the set up is like, except with more pumps.
jimrankin
07-27-2010, 03:08 PM
You can only lower the engine to the point where the pan now sits level with the lowest part of the flywheel so on some motor/trans units you don't gain a lot of ground. Dry sump does however gain a bit of horsepower by keeping the splash off the crank. It also helps keep the oil cooler so it keeps the motor cooler in turn. Unless your seriously tracking the car it's a bit of overkill, but then again, we all have thought about it. LOL
7evin
07-31-2010, 08:51 PM
If you are only using it for the street or just doing lite track days stay stock. It will always pump oil and do what it is suppose to do. :)
Most dry sump systems are belt driven, so alignment of you pump to the center line of your crank is critical. (see pic)
Of course ground clearance is a definite pro to this. Saves on JB wield. (if anyone needs
an oil pan for a s2k I have 2 that are still in the box) It eliminates the issue in the pic when
finished, you are about even with the frame.
Hoses and lots of hoses make for issues, (con)
where to mount the oil tank? or in our case custom build a tank to fit.
Lots of challenges, but I think that is what we all enjoy about these cars. :)
I would be happy to share more if you are interested.
beagley
08-05-2010, 02:11 PM
Lots of challenges, but I think that is what we all enjoy about these cars. :)
I would be happy to share more if you are interested.
Not that it makes sense for me to do it on my build, but I am interested in how you develop and/or decide to use a dry sump system. Do you have a build log of your car(s). What made you decide to use the s2000 engine? I've always thought they were a bit tall for use in a 7. Is yours track only? How do you determine how many lines and pumps are necessary? Is it a magic mathematical formula or is it based on the amount of oil that needs to be sent to the individual channels? I aplogize if I ask 19187642 questions, but I am quite a curious little boy, at least thats what my mom used to tell me.
Thanks,
Beags
jimrankin
08-05-2010, 03:13 PM
(1) How much ground clearance did you gain? I have a stainless steel skid plate that sits about 1/4"+ below the pan that so far has worked out pretty well, lots of road rash on it but the stock aluminum pan seems to still be intact. I looked at the engine sump casting to bell housing castings ratio and it looked like a really marginal gain (without modifying the bottom castings for the flywheel/clutch housing)
(2) What do you want for one of those pans? I've got a big Honda dealer about two blocks from work but they never seem to have what I want in stock. Either those Hondas never break or these guys have learned to work with zero inventory and live buy UPS overnight.
Third bonus question. Did you do the sump mainly for serious track use? The tank looks really trick by the way, nice work.
7evin
08-05-2010, 10:28 PM
Beagley:
1) how you develop and/or decide to use a dry sump system?
It became a necessity for us because we were pulling more lateral acceleration out of the
car then Honda had designed the oiling system to handle. RD rocket (chuck) was the first
to come across this. The development came from hours of research and phone calls.
Then buying the hardware and making it work.
2) Do you have a build log of your car(s)?
Our (Loren and I) whole goal was to push the envelope as far as we thought it could be
pushed, find the weak spots and make it stronger. We have a semi build log here on the
USA7s site. @ http://www.usa7s.com/vb/showthread.php?t=2107
Some of the stuff we were doing was kept quite because of development for the company.
3) What made you decide to use the s2000 engine?
Honda test these motors at 9000 rpm, max load for 100 hours.... It is one of the best
4 cylinder motors on the planet (IMO)
4) Is yours track only?
Our car is in full street trim. We could easily shave 200 + pounds off the car if it were
track only. We have everything from intercom, to suit heaters, to navigation to mp3
on the car
5) How do you determine how many lines and pumps are necessary?
Lines.... if there was a hole where oil leaked out of it we put a line there... :D
Pumps, We looked at the volume that the VTEC motor flows while in VTEC and pumped
it accordingly.
6) Is it a magic mathematical formula or is it based on the amount of oil that needs to be sent to the individual channels?
You have one input to the block, 1 pump that is adjustable for that and then you determine what you need to scavenge and
add pumps accordingly. Chuck runs 3 I think
on his XR7 we run 2.
http://auto.howstuffworks.com/fuel-efficiency/fuel-consumption/question331.htm
Jimrankin:
1) How much ground clearance did you gain?
At the end of the day most likely not much because we can now run the car lower to the
ground. I will post a picture of it before it was lowered.
2) What do you want for one of those pans?
I think I paid 2 something for them, I take
$100 each
3) Did you do the sump mainly for serious track use? The tank looks really trick by the way, nice work.
Thanks, We built the car in 8 weeks and there were alot of things we wanted to change
but were unable to because of our dead line. The last year and half we have be doing
just that. The Mojito version 2.0 should be right as rain... :) We expect it to out preform
version 1.0 on multiple levels. So we are trying to cover every base.
Sumpin it must occur when you are humpin it this hard... :D
Thanks for the interest guys if I can be of further assistance let me know.
JohnK
08-05-2010, 11:02 PM
check out http://www.speedracersportscars.com.au/PRBS2K.htm; for a schematic, here's a sketch of a typical setup.
My take on this is that parasitic losses from rotating parts slinging oil is considerable. Also, the scavenging can lower pressure in the crankcase considerably, which makes less work for the pistons going down and is partly responsible for the increased engine power output. Pumps are sold stacked so you can add stages. It's common to scavenge the head(s) as well as each crank throw bay (read Porsche, Ferrari engine specs). Lower engine mounting: lowering the center of gravity yields the greatest improvement in handling. The PBR project illustrates what you can do.
7evin's setup is very cool. I'm taking notes and saving my money!
JohnK
08-05-2010, 11:57 PM
7evin,
What are you running off the crank on the LEFT side of the engine? Power Steering?
7evin,
What are you running off the crank on the LEFT side of the engine? Power Steering?
I think he's running a supercharger.
beagley
08-06-2010, 08:39 AM
So it seems that the benefits of setting up a dry sump system (less friction in crankcase, no possibility of oil starvation, better control of oil temp and delivery) outweight the cons (extra weight of pump and oil, complexity with extra hoses, slight draw of hp from running the pump from the belt). Would that be a correct statement? I really want to develop a fairly bullet resistant (bullet proof is impossible) engine that goes like mad and will just work. I have grand ideas of what I want the engine bay to look like, but time will tell if thats realistic. :)
Thanks for the replies 7evin, what else do you know and are able to tell without fear of punishment?
7evin
08-06-2010, 08:44 AM
7evin,
What are you running off the crank on the LEFT side of the engine? Power Steering?
Good eye :) We call that POWER steering for the Rear tires .. :D
Hank: Bingo
It is our Rotrex Super Charger. C38-61
http://www.rotrex.com/Home/Technology/Product_Overview.aspx
Beagley: You pretty much nailed it. What motor are you running in your car?
pros
-more power with dry sump
-consistent oil pressure
-increase ground clearance for extremely lowered cars (oil pan is pretty low
-larger oil capacity
-inline oil cooler easier to run
-return lines for turbo easier to run
-less aeration
cons
-cost....
-belt breakage on external pump
-weight
-complexity
Know.... I find the older I get the more I realize I Know very little... :D
Fear.... That is reserved for the current form of Government we find ourselves under.
Punishment.... When my wife takes the Keys to Mojito and tells me I have been a bad boy...
This usually happens at the end of the month when she figures out how much money I have spent on
what she calls the other women in my life (Mojito). :D
Look around the site there are some really incredible people here that are way more knowledgeable than I,
who have posted some fantastic info. My Friend WestTexasS2K is one of them.
beagley
08-06-2010, 12:31 PM
Beagley: You pretty much nailed it. What motor are you running in your car?
Don't know yet. Feels like ive been in the planning stage forever now. The big problem is I don't have a place to build it. My wife and I are "hoping" to move in the next couple of years at which time I have already begun petioning for a bigger garage or detached workshop at which point my build will begin. My motor will probably come down to what I can find readily and the cost. I've got several ideas that I would like to use. I'm always up for some good discussions on which engines people use and why. For instance....
I've read a build log using Ford's 2 liter Duratec which was then supercharged for that "little" extra. Did a great job http://gtslocost.locostsites.co.uk/ (http://gtslocost.locostsites.co.uk/)
I've seen several using the S2k motor which are pretty awesome <insert 7evin here>.
I though that using the supercharged LSJ engine which was used in the 2005 - 2007 Cobalt SS. A step up from that would be the turbo charged LNF engine which was used from 2008 on in the same car. Fairly small power plants but produced a decent amount of power in their stock form. You could go crazy and add all the extras but wouldn't be necessary. The L67 mentioned earlier is fairly easy to find, but they are rather large and heavy.
edit: Then you also have the 13b and Renesis wankles to use......
I've even though about using some motorcycle engines, but the thought of running down the highway at 9,000 rpm doesn't sound like much fun. But blasting around a track does..... I guess I should just build 2 cars then huh?
Now, if I had limitless funds I would definitely be using the Hartley H1 v8. http://www.h1v8.com (http://www.h1v8.com)
What are some engine chioces any of you guys have done and what reasons did you pick it? I haven't seen too much on alternative engine designs either (I'm not opposed to running an EV or something like that). Sorry for the looooooooong rambling post.
Beags
Any ideas on running a dry sump on an Alfa Romeo-engined Se7en? (four-cylinder or V6)
JohnK
08-06-2010, 11:05 PM
Don't know yet. ...Beags
A suggestion here, with 20/20 hindsight. I gathered info for years and even spent time working in two different shops to gain experience in se7ens and performance development. When I finally took the plunge I couldn't believe how many "Oh, S***" situations I ran into, in spite of all my planning and experience. What I thought would take me no more than a year is going on 6 years. Now I have had a great time, but had no idea how much work it would take to turn a "kit" into something I could have some faith in. A rational person looking over my shoulder could well have suggested that I just push the thing over a cliff and buy an ordinary Caterham - and such advice probably wouldn't have been bad.
7evin
08-07-2010, 08:55 PM
(1) How much ground clearance did you gain?.
Here are a couple of pics to show the difference between wet sump and dry sump,
as far as ground clearance goes.
Keep in mind the engine has been lowered in the car a bit
7evin
08-10-2010, 04:54 PM
I have invited Gary from ARE to join our forum. He should be able to answer any and all
questions about dry sumps. He has a great deal of knowledge.
snookwheel
08-10-2010, 05:44 PM
Here are a couple of pics to show the difference between wet sump and dry sump,
as far as ground clearance goes.
Keep in mind the engine has been lowered in the car a bit
Those pictures should sell the dry sump idea! What a difference. It looks like you went from having to be VERY careful on the street to no issue!
JohnK
08-10-2010, 11:58 PM
I have invited Gary from ARE to join our forum. He should be able to answer any and all
questions about dry sumps. He has a great deal of knowledge.
OK, how about HEAT? I.e., getting rid of it. A wet sump gives you a big finned surface stuck in the air stream so it can shed heat under the car - unfortunately at the expense of ground clearance and power losses and ... When you put a dry sump in, you have all that hot oil now contained within chassis space, which there isn't a whole lot of in a Se7en. Standard equipment in a dry sump system is an oil cooler, which also has to be located somewhere, preferably not where it adds heat to something else like the engine's cooling system. Supercharging adds more power at the expense of more heat output, and thus more cooling problems. Little by little the guys who design successful race cars begin to appear pretty damn clever! My favorite is C. Chapman putting the radiators on either side of the chassis.
So... what are the different solutions for locating all the parts and keeping everything cool enough to work correctly?
7evin
08-11-2010, 10:29 PM
OK, how about HEAT? I.e., getting rid of it. A wet sump gives you a big finned surface stuck in the air stream so it can shed heat under the car - unfortunately at the expense of ground clearance and power losses and ... When you put a dry sump in, you have all that hot oil now contained within chassis space, which there isn't a whole lot of in a Se7en. Standard equipment in a dry sump system is an oil cooler, which also has to be located somewhere, preferably not where it adds heat to something else like the engine's cooling system. Supercharging adds more power at the expense of more heat output, and thus more cooling problems. Little by little the guys who design successful race cars begin to appear pretty damn clever! My favorite is C. Chapman putting the radiators on either side of the chassis.
So... what are the different solutions for locating all the parts and keeping everything cool enough to work correctly?
You are very correct, We use a Mocal oil cooler that uses coolant from the radiator. Of course you can see the oil tank is mounted above the passenger compartment.... this keeps the driver cooler... :) For us, we are spraying loads of alcohol... Nice cooling effect.
Of course these are all considerations when building the car, We will not be able to tell
how these things work until we test it. Allot of it gets lizard skin, but that only goes so far...
We are trying to make it as fast as possible but still keep it street-able.
7evin
08-11-2010, 10:31 PM
Those pictures should sell the dry sump idea! What a difference. It looks like you went from having to be VERY careful on the street to no issue!
Defiantly decreases the pucker factor wondering if it going to clear...
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