Dry Sumps And You.......

[Risking]

This may or may not work but I thought let's get a thread together for all those dry sump questions people have but either never ask or the threads get lost on the interweb.

I get pm's constantly with little questions about things that info is not easily available for. If everything can go in here the info will be easy to find for future dry sumpers.

It would be good if the handfull of guys who actually do set up dry sumps can spend some time to answer questions accurately. Dont want arguments but obviously there is more than one way to skin a cat so opinions are going to be had.

If it doesn't work the thread will go to the bottom and it's no great lose, but I know a few years back when I did my first RB dry sump there was no info around about sumps, breathers or anything else so if this can help so be it.

[Willis]

We could start with some basic info .. such as, what is a dry sump? what is the advantages of a dry sump system? why should i invest in a dry sump? etc etc.

Excellent idea though Risking as i have wondered about the specifics of a dry sump system and what is involved, rough costs etc.

[Risking]

A basic setup for an RB Will have an external belt driven pump, modified sump and a tank.

The pump is crank driven usually at 50% of crank speed. It creates a vacuum inside the engine and draws the oil from the engine and feeds it to the tank. These are refered to as scavenger stages. The pump draws back from the tank and pressurized the oil before feeding it back into the engine through one of several ways. That's a pressure stage.

Pumps are described as being an "X stage pump" 4 stage= 3 scavengers 1 pressure, 3 stage = 2 scavenger 1 pressure and so forth.

There are a few types of pump which only becomes relevant when you want to buy one really.

Tanks and sumps are a science all to themselves which I'm sure will end up as a topic in here eventually.

Costs can be up to and over 15k for a well thought out system using top shelf fittings and good quality gear. Costs can be cut using rebuilt 2nd hand gear which works fine an is 1/4 the price of new.

Advantages and disadvantages there are sooo many. A quick google search will teach you everything you need to know there.

[Angus Smart]

I was keen to do this... if i ever get my engine back.. was going to do it on the cheap however and get second hand parts from the Usa as its rather cheap option!! whether it will be too cheap (break blow up etc) is yet to be found out

should be able to get things made up if need be on the cnc machine my friend now has..

Brad... what would be an ideal pump to get? 3 stage? or 4 stage? i have a ton of photos i collected on my computer of rb's with dry sump/pumps

[wrxkilla]

Fantastic idea.

Good question Andrew. When I first purchased my dry-sump setup I thought more was better and went for a 5 stage pump, but it's never as simple as that lol. You tend to learn from experience!

Care to give us some more detail as to why you would choose, 3 or 4 or 5 stage Brad?

Cheers

Michael

[Risking]

The more stages the more oil you can circulate and the more vacuum you will pull in the crank case.

On a race car I normally use either a 4 or 5 stage. On a milder street car/weekend car I'd go a 3-4 stage tops.

Alot of people use a 4 stage and scavenge 2 from the sump and one from the head. It's not wrong but it's not ideal. The idea is create vacuum In the crank case and putting a scavenger in the head is not exactly helping to draw the oil to the sump pan where the remaining majority scavengers are trying to work.

Vacuum is always equal in all directions if the container ( engine) is sealed so scavenging from the head won't effect the vacuum levels but it is best if you can get all the oil flowing in one direction with gravity to the bottom.

With a 4 stage I'd normally run three pick ups in a sump channel. One from one center and one rear. With a five stage like my old race car had I'd use two channels one in front of the subframe one behind both with two scavengers feeding from them.

There is hundreds of sump design ideas out there nothing is really right or wrong, people scavenge in all different ways from all different positions.

I'd be interested to hear from others as to what they do with their scavengers and positioning.

On my road car I have a 3 stage to use. Two scavengers one at the rear ( scavenger on acceleration) and one 1/3 the way down the pan towards the front ( enough for heavy braking but far enough back to scavenge on acceleration too) usually with a 3 stage you will end up with excess oil in the pan, depending on the sump and channel design.

I'm doing a pan for an s15 at the moment for a 4 stage Peterson pump. The pump will be build into the pan and have internal scavengers when it takes some shape I'll put up some photos.

[bigmikespec]

Is going to a 5-stage purely to achieve constant vacuum around the 12-15" vacuum? If that is the case a "better" (i.e. Weiss, Auto Verdi)pump should be able to pull sufficient vacuum with 4 stages (maybe 3?) making it a lot more managable in terms of fitment, hoses and fittings.

What are people doing in terms of pressure and flow? i.e. how much of both? Obviously pressure is regulated easily but flow not so.

[Super_Dude]

What about tricks to seal the motor up, max vacuum, when to use a regulator. I have a 4 stage pump scavanging the front middle and rear of the pan. Its on an rb30 (no oil squirters) What is the max amount of vacuum I can run to ensure my engine lasts as long as possible while still freeing up some horsepower?

[bigmikespec]

From what I have read around 10-15" Hg to get the horse power gain; beyond that not many more gains to be had and it is more difficult with OEM seals etc.

[Risking]

With sealing up the engine using good quality seals is a must. I also machine up alloy half moons for the rocker covers, they don't always get sucked in but I have had it happen.

Normally I drill and tap the dip stick tube's hole and put a 1/8th npt fitting in there with a 6mm barb end. Let's me quickly and easily connect a vac gauge to the crank case.

Like mike said 10-15 is typical but 15 I personally think can be a tad high leading to little end wear. my engines I try to get them at a max of 12 or so. There is a few ways to do it. An adjustable bleed on the rocker cover, or I have used the same fitting tapped into the rocker cover with a vac line off it connected up to the air filter inlet pipe. I machine up some small restrictors with various size orifices and change them till I get the desired vacuum. A little harder to set up but costs nothing to do.

I also know a few people who run open breathers with no crank case vacuum.

[bigmikespec]

Good little tricks there Brad.

There are some sneaky oil mods to prevent starving the little end one is to have a hole bored all the way through the length of the con rod (usually using EDM) so when the oil drilling on the crank lines up with the hole in the big end of the rod you get a squirt of oil up to little end.

Some of the top racing teams in the US run up and over 20-25" Hg vacuum

[r33_racer]

You could get your pins DLC coated and with minimal lubrication should help that problem in the higher vacuum ranges. One possibility, though quite expensive I'd imagine.

[Ryan1200]

What system is adequate if the belt comes off at high rpm to stop the motor from damaging?? Is a low oil pressure engine cut out in the ECU enough to save you if the pump stops dead at 9000rpm? With a full cut out you still need to disconnect the engine from the transmission to stop it turning..... then you start praying you got to it quick enough i guess..

[Super_Dude]

I would rather just have a low pressure warning, if your coming around a corner and your engine quits instantly you might lose control and cause even more damage.

[r33_racer]

You can hook up an electric pump that can kick in if something goes wrong. However with the right guide discs on around the belt, it shouldnt ever come off unless something seriously big and bad attacks it.

[Risking]

I've never had a belt come off.

If the thing is designed properly and aligned there should never be a problem. It's not a common problem like people tend to stress about

I use a guide plate for the belt to run against.

[Evocoop]

Mine is a Hi octane kit with a 4 stage Barns pump. I've got it scaving from the lowest point on the front one at the very back in dash 12 lines and a dash 10 line from the back of the head. Kept one in the head as it was already there fron the old motor and had always planned to run open breathers. 1 Dash 16 line outta the pump into the tank and a dash 12 back to the pump. -12 outta the pump through the filter and into a water to oil oil cooler. Water to oil seems to help getting the oil up to working temp quickly as it now takes about 12 liters of oil. It goes back into the motor with a Grex adaptor into where the standard heater coil used to be with an RB30 oil filter nipple.

It's been running faultlessly for 2 seasons now and gives you every confidence when you don't have to worry about oil serging and having your rod and gudgen pin end up in the bell housing again.

The only time I have heard of a belt coming off is if the car throws a power steering belt and in turn flicks the dry sump belt off. But with the right balancer it shouldn't happen. I do however have a Defi advance system that has an audible alarm for oil pressure set just below 2.5 bar which is just under the idle pressure when oil is hot.

Plenty of other little things I've learned about it since it went in but they are definatly worth the investment.

[Beer Baron]

the hi octane kit seems to be pretty good value for just over $8K. still a bit to spend in terms of lines and not sure if it includes a balancer (another $800-$100) but considering all the gear is brand new and it inlcudes 4 stage pump, fittings, sump, bracket, drive system etc it's not too bad. proven on plenty of cars these days too.

[bigmikespec]

Not being rude Mr Baron but I think it is hideous at $8k for what you get. It is convenient for a builder with more money and no knowledge or inclination to do it themselves but it is way out of most reach for most who don't want oiling problems.

That being said it is proven on the track!

[wrxkilla]

I didn't end up using the hi-octane kit, but workshops do deserve a return for the time and effort testing locally developed products for our benefit..