CB Performance Dry Sump Pump Installation

[andy198712]

http://www.vwspeedshop.com/product.php? ... 485&page=1

thats the top half of there kit.....

bmd sounds good though

[FJCamper]

Above: Tank measurements. Average for 3-gallon style rectangular types.

Hi jim.fernish,

Here's the info on our type of tank. The taller cylindrical tanks are supposed to be better at deaeration, as described here:



Something else we'll be looking for is foam blowout at the vent from the shorter tanks. Taller tanks allow some expansion
space. We picked the shorter tank for space consideration, and we could get it mounted lower to avoid drainage back
to the engine.

We'll see.

FJC

[Devastator]

Thinking about going with a dry sump, so I'me resurrecting this thread.
What is the advantage of running the CB pump over adding a sump to a full flow system with a stock style high volume pump?

[Piledriver]

Less oil in the case= less oil to blow around.
Going around long sweepers at high RPM, (or a long series of hard left/right cranks) esp with a large pressure stage pump=run out of oil, amazingly fast.

The former I assume would lead to somewhat less oil usage on the street.
The latter keeps your bearings... intact.

[Devastator]

I understand the reason for dry sumping, but I don't understand the oil pump change.

[Piledriver]

I'm not following... You cannot dry sump with a single stage pump, so the question boils down to dry sump vs wet sump.
If a large deep sump is not an option, DS is the only sane method, and if I were to ever build a T1, I would not think twice about a CB drysump pump setup, it would be a given. I'd even consider it on a stocker (along with a sand seal and case evac)

On a T4 or WBX that will (in reality) hold 5 quarts in the wetsump, it's more a question of usage.

The CB DS pump is "tiny" by most standards, but that also means it clears most fan pulleys, which is a win.
(on a T4, it will clear a stock T1 size conversion pulley)
A 21mm pressure stage is also plenty if you feed it only a steady diet of actual oil, vs an intermittent frothy air/oil milkshake mix.

Given a little love on the feed to the pressure stage and perhaps larger, more direct plumbing on the scavenge side, as well as ideally rerouting the pressure relief flow back to the tank rather than having to resuck it out of the sump constantly... it is plenty of pump for most applications.

[owdlvr]

I understand the reason for dry sumping, but I don't understand the oil pump change.

To make it as simple as possible, you need two pumps in a dry sump setup. One pump pulls oil from the tank, pressurizes it, and sends it through the motor. The second pump removes oil from the motor and puts it back in the tank. Each pump has a suction side, and a 'pressure' (or pushing) side. Think about removing one of those two pumps in the system, what it would do. Now you should be able to understand why a special pump is required.

Now, there are a number of ways to package the pumps or "stages" needed. And it gets complex from here. But the first thing is to understand why the pump (which is multiple pumps packaged as one) is special.

Hope that helps,

-Dave

[Devastator]

My confusion is, apparently, coming from the pics of the pump shown at the beginning of this thread. It looked like a single stage pump. Is it, indeed, a 2 stage? If so, where are the other inlet and outlet ports?

Thanks Dave. I understand the basic dry sump setup, and appreciate your response, but as I wrote above, it is the pump shown that is confusing me.

[Steve Arndt]

CB is a two stage dry sump pump. 21mm pressure, 26mm scavenge stage. The difference is that the CB isn't full flow in the normal plumbing fashion we are used to (it can be though).

[Fiatdude]

Just me coming up with a crazy idea -- -- about the issue of oil leaking back into the engine,,, I wonder if using a mechanical fuel injection high speed by-pass with a,, say 10 - 15# spring in there,,, would that be enough to hold back the oil when the engine is off and yet enough to allow the oil to be pulled through when running -- don't know if they come in #10 an -- I think the biggest I've seen is a #8 -- -- maybe double up #8's -- just thinking at keyboard LOL

http://www.hilborninjection.com/product ... &CatId=213

[Piledriver]

My confusion is, apparently, coming from the pics of the pump shown at the beginning of this thread. It looked like a single stage pump. Is it, indeed, a 2 stage? If so, where are the other inlet and outlet ports?

Thanks Dave. I understand the basic dry sump setup, and appreciate your response, but as I wrote above, it is the pump shown that is confusing me.

It is indeed a 2 stage drysump pump.

The CB pump is designed to plug into a T1 case... the pressure stage output takes a tortured path down through 2 layers of pump and out at the stock case oil pump output port...Sort of a bug for hipo/full flow use, but on a typical DS setup its already cooled and filtered by that point. 26mm scavenge side is a bit small for scavenge side filtering and cooling, though.

It would take (you) all of 10 minutes to plug that and stick on a full flow cover and blow the inlets/outlets up to -8 or -10 or maybe even larger. The pressure stage inlet port allegedly needs to be as large as possible, several folks have said over the years that's the main "required" mod for good oil pressure.

On a T4 or WBX case, the pump can easily be converted to a straight through setup, using the oil filter outlet ports for the scavenge outlets, by plugging the pressure pass through and opening up the "factory" case ports for scavenge side flow, and using a full flow cover on the pressure stage outlet.

[squeakie]

My confusion is, apparently, coming from the pics of the pump shown at the beginning of this thread. It looked like a single stage pump. Is it, indeed, a 2 stage? If so, where are the other inlet and outlet ports?

Yeah! Where are the other ports? I double-checked the pictures at the beginning of this thread and even the diagram doesn't show the case scavenge ports. Now, what if the existing internal to the case ports are open and being used to scavenge the case - these won't be seen, but shouldn't it still have at least one more port to allow this case oil be put into the external tank?

I think we all understand how a dry sump works. I think we can also agree that these pictures are slightly confusing.

[Piledriver]

My confusion is, apparently, coming from the pics of the pump shown at the beginning of this thread. It looked like a single stage pump. Is it, indeed, a 2 stage? If so, where are the other inlet and outlet ports?

Yeah! Where are the other ports? I double-checked the pictures at the beginning of this thread and even the diagram doesn't show the case scavenge ports. Now, what if the existing internal to the case ports are open and being used to scavenge the case - these won't be seen, but shouldn't it still have at least one more port to allow this case oil be put into the external tank?

I think we all understand how a dry sump works. I think we can also agree that these pictures are slightly confusing.

It uses the factory oil pickup for scavenge suction, and the scavenge outlet is on the 3/4 side.
The "hidden" pressure stage outlet is the factory pump outlet port... the pressure passage goes all the way down through both stages, "non full flow" style. It's easily corrected for full flow cooling/filtering if desired by plugging that port and using a full flow cover. (Iron or steel cover, preferably)

I posted some pics ages ago showing an extensively modded CB pump that I set up to fit in a 914, between the factory engine mounts.
...pass side mount was modded to allow a 3/4" tube for the pressure stage feed from the tank to pass through the mount.. in retrospect 3/4 tube is probably too large, but I only paid $20 for that pump at a swap meet, so I got to experiment

inner-plug.jpg

[squeakie]

ahh, thank you, Pile. That makes perfect sense - I had assumed it was like that, but wanted to be sure.

[Devastator]

Thanks Steve. That answered my question.
I believe there is an electric solenoid available that turns on and off with the ignition and can plumbed into the sump.