Dry sump system?

[stretch]

I'm thinking about converting my street / strip car to dry sump oiling.

Can someone please have a look at the attached sketch (apologies it's a little rough), and just confirm i've got the basic layout correct?



I've got a few questions for you guys as well, what size oil lines are recommended?  Do you need to put a stop valve in the line from the tank to the pump to stop the sump filling up under gravity when the car isn't used?  Does anyone have the dimension of a 2 stage autocraft pump from the surface that mates with the case to the end of the pump?

Cheers.   

[owdlvr]

Basic layout looks good, will you have an oil cooler plumbed into the system?

For a street/strip car you can probably get away with using the factory pickup location (depending on the drysump pump you select). I'm using the bugpack in my rallybeetle, as is Mark Huebbe in his stage-rally beetle. Depending on where the tank is located, you will absolutely need a stop valve between the tank and the engine. The only way around this is if you mount the tank low enough that the oil can't drain back into the engine. With my tank I drain about 2L in a 24 hour period. So if I'm parking in the garage overnight, I don't need to close the valve...but if I think I might have the car parked longer, I definitely close the valve.

-8AN hoses are used for all lines in my car, some guys will say -10AN from Tank to pump, and from pump back to tank...but as the fittings on my pump were all 1/2" I didn't feel the need to bore them out without testing first. 2.5 years and I haven't had any issues with oiling as far as line size is concerned.


Shut-off Valve is on the right hand side, just above the cylinder tin. With the race seats reaching the tank proved too difficult for daily use.


There have been a bunch of changes since this photo, but general layout remains the same and gives you an idea of where my tank is installed. Note that I raised the package tray 3", so my tank sits "halfway" under a stock package tray.


-Dave

[hotrodsurplus]

To prevent cavitation make the lines from the sump to the pump and from the tank to the pump as big (large diameter) and short as possible. Any restriction in those lines will create a negative-pressure environment that reduces the vapor temperature (the temperature at which oil vaporizes, aka cavitates).

Still run the larger lines even if the fittings are smaller than the line size. Remember that resistance increases with length. So an oversized line will flow quite well even if it has small fittings at the ends. A few feet of the small line will really diminish the flow capacity.

I think -8 is more than adequate for any line that endures positive pressure. I wouldn't be afraid to step up to even -12 on the lines that may potentially see any negative pressure. It may be overkill but it can't hurt either.

 

[stretch]

Thanks guys, that's really useful information.   

Dave, not sure about a cooler, I don't have one at the minute with the standard wet sump & i've never needed one.  Oil temp's have never been a problem.  I'm planning on mounting the tank on the parcel tray, behind the rear seat, so i'll definitely have to fit a stop valve.

Do you still need to vent the rocker covers to a breather box with a DS system?  Or is it a better option to 'force' the oil back to the sump under pressure?  i.e. drill & tap the case & take a line directly from the rocker cover back into the base of the case.

[hotrodsurplus]

Why not run an electric hydraulic valve? Years ago a family friend ran one with an Accusump. It worked great. When you turn on the ignition the valves open. When you shut off the ignition the valves shut. You can get them in different sizes for hotter operating temperatures and greater pressure but this should give you an idea.

http://www.grainger.com/Grainger/RED-HAT-Solenoid-Valve-2HTX5?Pid=search

The lowrider crowd uses similar valves for lifts in its low-lows so you could probably get an even better deal in that market. The valves are usually referred to as dumps.

The lowrider crowd originally used aircraft surplus parts (some still do) and you can probably do the same. You can find dumps in industrial junkyards that have trucks with hydraulically powered components like lift gates and tilt beds. Just be careful because some big trucks use 24-volt electrical systems. But you could probably get a high-quality dump for 1/10th the price of a new one. They live forever too.

[owdlvr]

The electric valves, commonly used with accusumps, have their drawbacks. I can't remember if it's a flow restriction, or what the issue is, but they recommend them only for street cars and not for race cars. One would need to hit the Canton Performance website to confirm.

Stretch:  On my high-revving 1776 I have vented the fuel pump mount, the oil filler, the 1/2 valve cover and the dry sump tank. I really think the venting takes a little experimentation, as what works flawlessly on my engine is definitely not the "usual" or recommended setup!

-Dave

[hotrodsurplus]

The electric valves, commonly used with accusumps, have their drawbacks. I can't remember if it's a flow restriction, or what the issue is, but they recommend them only for street cars and not for race cars. One would need to hit the Canton Performance website to confirm.

My apologies. I assumed that this was for a street application since you posted it to the cal-look forum and cal look refers to a style of road-going cars. I do know that drain-back valves are discouraged because they can impose a restriction on the inlet line which can cause cavitation. However, I think that a sufficiently oversized electric valve would work. I just checked the Canton site. The company actually sells electric valves for racing applications.

Peterson is a HUGE name in the sprint-car world. It makes some of the best pumps going. It also posts a lot of information on its FAQ. There's good information there about cavitation and how to vent a dry-sump system.

http://www.petersonfluidsys.com/tech_faq.html

[stretch]

Yes, it's a street car.   

Looks like this is going to take some experimentation / setting up.  Oh well, what else is there to do over winter.   

[hotrodsurplus]

Oh well, what else is there to do over winter.   

Loose women, scotch, and cocaine?

[dannyboy]

Yes, it's a street car.   

Looks like this is going to take some experimentation / setting up.  Oh well, what else is there to do over winter.   

forget it and fit nitrous 

[hotrodsurplus]

Just out of curiosity, what will the dry sump give you that a conventional wet-sump system can't? I know the virtues of dry sumping but I think they would be lost on a street application. Many here regularly prove that a modified wet-sump system is more than adequate for a very high-performance engine. The beauty of a VW is its simplicity and a dry sump adds a lot of complexity. If it solves a real issue then it justifies the complication and expense.

I may be wrong but I think a dry sump on a street car (especially one that goes mostly in straight lines) is a solution to a problem that really doesn't exist.

[Lids]

ground clearanace 

[Neil Davies]

Yes, it's a street car.   

Looks like this is going to take some experimentation / setting up.  Oh well, what else is there to do over winter.   

forget it and fit nitrous 

If I had Facebook I'd hit the Like button about now...

[Fiatdude]

The only change I can recommend is moving the filter (and possible cooler) to the line going from the pump to the tank -- the reasoning is this, IF you have a failure and start getting debris in the oil it goes immediated into the filter and then you won't have to worry about flushing the tank, cooler and all your lines and you only possibly lose one stage of your pump rather than 2 or 3

[peach_]

The only change I can recommend is moving the filter (and possible cooler) to the line going from the pump to the tank -- the reasoning is this, IF you have a failure and start getting debris in the oil it goes immediated into the filter and then you won't have to worry about flushing the tank, cooler and all your lines and you only possibly lose one stage of your pump rather than 2 or 3

Sorry to disagree but i wouldnt do all of  the above, my back ground comes from Gt and historic circuit racing, i would leave your system as it is with the filter on the 2nd stage, due to the fact that if the motor shits its self the oil pump will seize with the broken parts and not make its way back into the engine causing more damage. In my experience of dry sumps the massive red light of no oil pressure on the dashboard when the pumps seizes and alerts the drive to the problem is a better/faster warning than a slow gradual pressure drop that you might not notice till its to late, thus causing more damage to more expensive internal parts  than a gear on a pump or a complete new pump.

If your running a cooler yes put it inline from the pump to the dry sump tank.

Also is your vent on the dry sump tank your only breather and is it going straight to atmosphere ?

Cheers

[Ron Greiner]

Your oil line from the the oil pickup of the motor to the pump is incorrect!
the oil pickup tube goes to the right side of the motor but the fitting closest to the block!
attached is the correct oil line pathway

[stretch]

Your oil line from the the oil pickup of the motor to the pump is incorrect!
the oil pickup tube goes to the right side of the motor but the fitting closest to the block!
attached is the correct oil line pathway

Thanks Ron, so basically I had the pressure & scavenge round the wrong way.

[Fiatdude]

...

[dannyboy]

Your oil line from the the oil pickup of the motor to the pump is incorrect!
the oil pickup tube goes to the right side of the motor but the fitting closest to the block!
attached is the correct oil line pathway

Thanks Ron, so basically I had the pressure & scavenge round the wrong way.

that wont end well mate 

[stretch]

Your oil line from the the oil pickup of the motor to the pump is incorrect!
the oil pickup tube goes to the right side of the motor but the fitting closest to the block!
attached is the correct oil line pathway

Thanks Ron, so basically I had the pressure & scavenge round the wrong way.

that wont end well mate 

Only on the drawing Danny, I haven't even bought the pump yet !!