Big Boost lots of Revs? Dry Sump

[pdxmotorhead]

Starting a new thread,, Something I didnt think about till a day or so ago,, but makes sense to me is a dry sump BMW engine... ANY BMW engine..

So I handle several race cars that have dry sump engines.
Random thoughts....
All 911 engines are dry sump... For many reasons.
Pretty much all real high performance bike motors are sort of a dry sump.
You still need a crank scraper.


Good things about a dry sump:
- Creates solid crank case vacume.
- Cools the oil.
- Allows any amount of engine oil you care to pack around.
(a 2.0 911 motor holds between 6 and 14 quarts of oil depending on the year car and phase of the moon.)
- Allows massive volume and pressure. (2.0 cosworth sprint, 100lbs pressure and 10x the volume if you want it...)
- Allows you to raise the bottom of the oil pan up to the shallow level, and then drop the motor lower center of gravity.
- Oiling is almost never a problem.
Bad things:
- COST. youll spend 2500 on a dry sump system if your a cagey shopper.
- Its work to put in, a bunch of the cost is the Aeroquipe hoses to make it work.You NEVER use plain hose on a dry sump system...
- Need a oil tank and for it you need space. A typical tank is 10" x 24 to 30" tall.

How they work.

A dry sump system has a tank to hold the oil. (Usually at least 2 gallons.)
there is a special multi segment pump that does three things,
1. scavenges all the oil out of the sump. (Usually at least 2 pump stages.)
2. Pushes it back to the tank (Scavenger section does this.)
3. Pushes the oil into the engine. (1 Pump Stage)

The scavenger pump stages job is to keep oil out of the motor, its a very high volume low pressure part of the pump. It will pull enough vacume to suck your valve cover gaskets inside. You NEED to use adhesive on both sides of all crankcase gaskets on the engine. Wicked nasty adhesive.....

The oil is then blown back to the tank

The oil settles through a series of weirs in the tank till its foam free in the bottom of the tank. (Huge benifit here for turbo engines.)

The supply stage of the pump sucks the oil out of the tank and shoves it into the engine via the filter and cooler, the pump has an adjustable bypass to set your oil pressure with.

The pump is driven by a cog belt like a itty bitty supercharger. Usually at about 2/3 of the engine RPM. The belt seem to last forever. They are the same style as drive a lot of harley motorcycles just shorter..

Cool stuff about a dry sump,,,
1. It will work upside down... (Scary but true...) Almost all the stunt planes are dry sump....
2. It adds power, mostly due to the vacume but also because it almost eliminate oil mist (Windage) from the enigine.

Youe engine will need some changes,
1. You'll need to re-work the stock oil pump mounting area to be flow through, the pump will be gone... Ive seen stock pumps gutted and the un-needed drive holes welded shut.
2. You'll need to rework the oil filter mount, it will become a flange to attach the large (1" hose supply line) from the pump.
3. Oil pan. You'll need one with scavenger ports welded on and the sump removed. (These are made by Canton for MANY engines.)
4. The engine HAS to be 100% as air tight as you can make it ccv, pcv etc all gone... Plug every unneeded hole. Other wise you get the reverse of oil leaks...

Turbo?
1. You add a T into the main supply oil line and use a Hillborne "Pill" holder from mechanical fuel injection to provide the correct size orifice to get the volume you want to the turbo.
2. on one of your scavenger hoses you put in a T and connect the drain of the turbo to it. There will be NO oil buildup or foam issues after this...

Ok so hope this is interesting to others...

Link to diagram of a dry sump system.
http://www.stockcarracing.com/techar.../photo_01.html
Cheers.
Dave

[xxxJohnBoyxxx]

Very cool Dave. Thanks for the good detail on this. How reliable are the dry sump pumps for daily driving? Could you expect 200,000 miles out of one or do they need a rebuild like every 25K miles?

Thanks, John S

[pdxmotorhead]

They are the last thing to wear out in a porsche...

Basically its 4 oil pumps in a stack, so I'd expect the pumps to last as long as any oil or hydraulic pump. The housing is usually anodised aluminum and the gerotor pump gears are just like your factory pump (Maybe bigger )

With a careful install making sure the belt is properly tensioned I cant imagine it being a wear item. I can have one rebuilt (Another benefit) for about the price of a stock oil pump. You would probably do it yourself, its just a few flat gaskets o rings and maybe new internal gears. The only ones I've had to rebuild had digested shrapnel from blown motors at the track. ( hey NOTHING likes a 11K rpm money shift.... ) Of course if you ran the thing out of oil, it would be just like running a stock pump dry, eventually you'd toast the unit.... I've seen pumps that are over 15 years old that have outlived multiple race engines...

The new Vette is dry sumped as well. They started with the comp package cars and now all the hot ones are.

Based on watching your threads, I'd say for any of us that are HP addicts or just motor heads the pump is likely not going to be what we wear out or break.. LOL..

The only mystery to a dry sump is sorting the oil flow through the engine block so you make sure the oil goes in one point, and comes out in the pan... all the ones I've helped do or done used the stock oil filter location as the input supply point for the main oil, that means plugging a gallery to make sure all the oil is going into the main oil galley. Not rocket science, I check them with a bare block on a stand with a garden hose hooked ot the main input point. Make sure I have water coming out where I expect.

One more oddball item, a dry sump can easily over oil the engine top end, sometimes we plug the oil galleys in the block and drill a hole in the head so we can put a dedicated oil line with a restrictor in it to keep the top end oiled but not over-oiled...
Or you drill the supply galleys in the block, and put in threaded restrictors, depends on the engine... Its also possible to mock the head on and drill a new access port into teh exisitng oil galley down into the block then stepping the hole so you can externally remove the restrictor plug to change the hole size.

You treat it just like putting in a high volume oil pump in any rebuild, you need the right amount of oil everywhere...

It would be a cool project, I'd check out Speedmart or one of the dirt track sources, there are big ones in your state. (FL?) youll need to build the bracket to hold the pump. and the hoses should drape naturally form tank to pump as possible, try and avoid hoses that climb and drop between the pump and tank on the main supply leg or the scavenger tubes.

There are dirt track swap meets all over, good places to pick up lightly used stuff.

Dave

[Jean H.318TI]

i was just thinking about this the other day and they already make the oil pans for the m4x motors just need to figure out the pump mounting and stuff but this would be a great idea, would be perfect for my turbo car, because the turbo needs lots of cooling specially after drifting