GermanLook Forums  

Go Back   GermanLook Forums > Technical Section > Engines

Reply
 
Thread Tools Display Modes
  #1  
Old February 13th 2003, 13:33
fast70's Avatar
fast70 fast70 is offline
Registered User
 
Join Date: Jan 2003
Location: Gibson City, IL
Posts: 54
Dry Sump

I have been wondering about a dry sump for some time now and have a couple of questions. First, does it require a special dry sump case or will a stock T1 version work? Can the oil from a full flow mod just run through a dry sump tank? What does a dry sump pump do that makes it special? What are some of the advantages of having a dry sump?


These questions are probably stupid,
fast70

:stupid:
Reply With Quote
  #2  
Old February 13th 2003, 14:36
kdanie kdanie is offline
Registered User
 
Join Date: Aug 2002
Location: Petaluma CA
Posts: 358
A dry sump oil pump will have multi stages, that is more than one pump. A normal pump will scavange your case to the tank but you have no way to get oil from the tank to the system under pressure. A dry sump pump will have a scavange pump (sometimes more than one) to pull oil from the engine and put it in the tank and a pressure pump to suck oil from the tank and pressurize the engine.

A normal case can be used.

Advantages? More HP due to less drag on the crank from oil sloshing around it. More consistant oil supply, the stock oil system can suck air in certain circumstances.

Is a dry sump system necessary? Yes, if you need one, like road racing where cornering can expose the stock oil pickup or drag racing where every possible HP is desired.

ken
Reply With Quote
  #3  
Old February 13th 2003, 17:41
lightning bug's Avatar
lightning bug lightning bug is offline
Registered User
 
Join Date: Jul 2002
Location: Philadelphia, Pennsylvania USA
Posts: 462
Not a stupid question at all. CB's dry sump system only uses 1 pump. It has 2 sets of gears so an external pump isn't needed. Its also not all that expensive. The above is true and also you never have to worry about starving your bearings of oil. You also eliminate the need for a sump extension. With a dry sump you'll have a remote tank to hold your oil. CB's is something like 8 or 10 quarts and is baffled to eliminate foaming. I'm going to use this system on my T1 2276T street car.
__________________
Julian
'74 Super

"If you are under control you're going too slow" - Parnelli Jones
Reply With Quote
  #4  
Old February 14th 2003, 06:11
Chris Percival's Avatar
Chris Percival Chris Percival is offline
Registered User
 
Join Date: Jul 2002
Location: Bristol, UK
Posts: 396
How does the crank get lubed on a dry sump system?
Reply With Quote
  #5  
Old February 14th 2003, 13:21
Shad Laws Shad Laws is offline
Registered User
 
Join Date: Nov 2002
Location: Stanford, CA
Posts: 125
Hello-

I'm going to elaborate a bit in an effort to clear up some confusion...

Let's ignore the oil cooler for a sec because there are many different variations on how to do it.

A typical wet sump system works like this:

Sump -> Pump -> Filter -> Pressure Relief -> Engine Oil Galleries -> Sump

The sump is basically a "catch" below all the engine components, using gravity to get the oil back in the sump.

A typical dry sump system works like this:

Oil Tank -> Pump Pressure Stage -> Filter -> Pressure Relief -> Engine Oil Galleries -> "Sump" -> Pump Scavenge Stage -> Oil Tank

The oil is drawn from an external oil tank (where aeration is removed and there are no moving parts to create windage) and put through the engine as normal. Then, one or more scavenge stages suck the sump of the engine dry, often taking up air, too. Additional stages could suck from rocker boxes or turbos.

Usually, the oil coolers for a dry sump system are placed on the scavenge side of the system - after the pump scavenge stage and before the oil tank. This means that they have no pressure running through them. It also means that the pressure stage of the pump takes oil as directly as possible straight from the oil tank to the engine.

Take care,
__________________
Shad Laws
Reply With Quote
  #6  
Old February 15th 2003, 14:47
Type 5 Joe Type 5 Joe is offline
Registered User
 
Join Date: Jan 2003
Location: High Desert, Central Oregon, Redmond
Posts: 10
I actually use these on my motors...

Any application would benefit from these...

I do mostly off-road.

Positive piston displacment, the main benefit. Less combustion pressure in the back-side of the pistons, frees up the power.

You'll need to run an inlet hose (from the tank to the pressure pump) that has three times the flow volume, or you'll get low oil pressure readings.

Making an effective oil breather system for the oil/air (tank) is the big problem. Nobody makes a good one, and I've got about 25 hours into mine.

Shad is basically correct on his post.

- Joe
Reply With Quote
  #7  
Old February 16th 2003, 13:50
chigger chigger is offline
Registered User
 
Join Date: Sep 2002
Posts: 142
I just finished a major search on this subject the other night.
CB has the least expensive and easiest to use pump. You would have to blue print it just like a regular pump. The large quantities of oil the tank holds would definitely help with cooling the engine. Another reason to use it is so you can set your motor lower or the car lower without worrying about the ground clearance problem of a added on sump.
The only problem the mod seems to have is I think they recomend a smaller pulley to clear the pump. The information on the site was not exactly clear. Without the actual parts it is hard to know.
Reply With Quote
  #8  
Old February 16th 2003, 23:06
CLKWRK's Avatar
CLKWRK CLKWRK is offline
Registered User
 
Join Date: Aug 2002
Location: St. Catharines, Ontario
Posts: 382
Dry Sump

Helo everybody,

I am running a dry sump in my ghia. It takes 15 liters of oil to fill the system, so oil changes are not cheap.
I tried using a CB pump, but I diddnt like it, so if anyone is looking for a used CB two stage dry sump pump, I have one for sale.

Bry
__________________
GL ghia restoration:
http://s473.photobucket.com/albums/r...20restoration/
__________________________________________

Last edited by CLKWRK; February 16th 2003 at 23:16.
Reply With Quote
  #9  
Old February 17th 2003, 03:21
Wally's Avatar
Wally Wally is offline
Registered User
 
Join Date: Nov 2002
Location: The Netherlands
Posts: 2,542
You guys mention that the windage effect of the crank and piston back side is drawing power. Doesn't the factory 914 ' windage tray' eliminates that effect largely?
Also, neutralizing the windage effect by the windage tray, I thought that the a multi stage dry sump pump costs more power to drive it than it freed, thus resulting in a less power situation with a dry sump system? The mean benefit then left being the secured lubrication with racing applications...
Poor quality dry sump pumps leak and lose pressure losses because of different materials expanding differently (iron/aluminium) and bearing issues of the pump gears. Therefore good dry sump pumps are very expensive ($ 500,-- - $ 700,-- or more).
Also, most all reputable tuners in Germany use a stock 24 mm pump in their own (!) engines and make regular drag starts with it, even in 226 DIN hp (tested) 2733 cc cars that do 0-62 in 4,5 sec.
My guess therefore was that although the system in itsself is very good, we obviously don't need it in a street car application.
But if anybody did any testing and found they gained hp, I would definitely reconsider...
Walter
Reply With Quote
  #10  
Old February 17th 2003, 04:40
Chris Percival's Avatar
Chris Percival Chris Percival is offline
Registered User
 
Join Date: Jul 2002
Location: Bristol, UK
Posts: 396
I thought parts of the crank were splash lubricated?
Reply With Quote
  #11  
Old February 17th 2003, 13:19
lightning bug's Avatar
lightning bug lightning bug is offline
Registered User
 
Join Date: Jul 2002
Location: Philadelphia, Pennsylvania USA
Posts: 462
Clockwork

What didn't you like about the CB system? Thanks!
__________________
Julian
'74 Super

"If you are under control you're going too slow" - Parnelli Jones
Reply With Quote
  #12  
Old February 17th 2003, 13:50
Alex's Avatar
Alex Alex is offline
Registered User
 
Join Date: Aug 2002
Location: Oakville, Ontario, Canada
Posts: 1,115
In the engine gallery you will find a picture of a dry sump pump that Eddy Remmele made. It is 30/26 I believe but from the setup identical to the Schadek (CB) pump. He told me that he will not make them anymore. It was not cheap. If there is enough interest maybe be would get him to do them again.


Alex
Reply With Quote
  #13  
Old February 17th 2003, 16:16
kdanie kdanie is offline
Registered User
 
Join Date: Aug 2002
Location: Petaluma CA
Posts: 358
Chigger, The large quantities of oil do not help cool the engine, it just prolongs the warm up time until all the oil is up to a useable temp. All the oil must be at 180 deg. F before you run the engine hard our you may have problems. You must run a good cooler and thermostat in the system. Most racers that use drysump systems have heaters installed to preheat the oil and reduce warm up time.

Chris, All the bearings are pressure lubricated, the pistons and cam/lifters get "splash" for lubrication but if there is too much oil getting wrapped around the crank it costs HP. I think squiters to the pistons, cam/lifters with quick drainback is the best way to go.

Wally, I have heard that the 914 windage tray can actually make the problem worse by not allowing enough oil drainback on high volume systems. I don't have any experience with it though.

ken
Reply With Quote
  #14  
Old February 17th 2003, 17:42
Chris Percival's Avatar
Chris Percival Chris Percival is offline
Registered User
 
Join Date: Jul 2002
Location: Bristol, UK
Posts: 396
Thanks Ken, so you need to rig up some lubrication of the cam/lifters and what about the big end bearings, they pressure lubriated too? Sorry for hijacking the thread guys, just a good chance for me to learn something.. Might be somthing to think about in the future for the track, though for now its just a deep sump for me...
Reply With Quote
  #15  
Old February 17th 2003, 22:07
Shad Laws Shad Laws is offline
Registered User
 
Join Date: Nov 2002
Location: Stanford, CA
Posts: 125
Hello-

You guys mention that the windage effect of the crank and piston back side is drawing power. Doesn't the factory 914 ' windage tray' eliminates that effect largely?

It helps, but not as much as a dry sump.

Nowadays, just about _every_ production engine has *some* sort of windage tray, whether integrated into the block (for an aircooled example, look at a Corvair) or in the oil pan.

A good dry sump system helps quite a bit more, though.


Also, neutralizing the windage effect by the windage tray, I thought that the a multi stage dry sump pump costs more power to drive it than it freed, thus resulting in a less power situation with a dry sump system?

No. The higher you go up in racing, the more stages they use...

They also use vacuum pumps to drop the air pressure in the crankcase, further reducing windage.


Poor quality dry sump pumps leak and lose pressure losses because of different materials expanding differently (iron/aluminium)

Iron gears in an iron-bodied pump will give the highest pressure. Simply seal the iron body to the aluminum case on the outside and you're golden. Yes, I know this is contrary to "common knowledge," but think about it...


and bearing issues of the pump gears. Therefore good dry sump pumps are very expensive ($ 500,-- - $ 700,-- or more).

The closer and closer you want to get to *perfect*, the more it costs.

For a situation where competition isn't that heavy, i.e. a street car or amateur race car, a simple 2-stage pump is *often* the best bang-for-buck.


Also, most all reputable tuners in Germany use a stock 24 mm pump in their own (!) engines and make regular drag starts with it, even in 226 DIN hp (tested) 2733 cc cars that do 0-62 in 4,5 sec.

The stock pump isn't that bad...

My guess therefore was that although the system in itsself is very good, we obviously don't need it in a street car application.

Of course you don't *need* it. But it's a nice thing to add :-).

But if anybody did any testing and found they gained hp, I would definitely reconsider...

All well-built dry sump systems save power.

I thought parts of the crank were splash lubricated?

A dry sump system lubes the main, rod, and cam bearings, and the lifter bores (and therefore pushrods, rocker arms, and upper valvetrain) the _same_ way as the wet sump system. It's pressurized from the oil galleys, after the last pump stage (which, for a wet sump system, is also the only stage :-).

The lifter faces, cam lobes, wrist pins, and cylinder walls are splash-lubed from the oil spray coming off the main rotating assembly. Of course, other modifications can change this a little one way or the other.

In the engine gallery you will find a picture of a dry sump pump that Eddy Remmele made. It is 30/26 I believe but from the setup identical to the Schadek (CB) pump. He told me that he will not make them anymore. It was not cheap. If there is enough interest maybe be would get him to do them again.

There's a 914 racer somewhere on the East coast that custom-makes them, too. But, like Remmele, I think he's kinda lost interest in making more due to tiny quantity. If curious, ask Chris Foley for more details - I'm just repeating what he told me.

Chigger, The large quantities of oil do not help cool the engine, it just prolongs the warm up time until all the oil is up to a useable temp.

_Absolutely_ correct.

If you use a dry sump, you _really_ need to use a real, temperature-based thermostat, not the pressure-based stock one.

Take care,
__________________
Shad Laws
Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 03:48.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2022, vBulletin Solutions Inc.
© www.GermanLook.net 2002-2017. All Rights Reserved