Dry Sump

Post by **Leatherneck** » Sat Oct 28, 2006 7:10 am

Start a topic here some might not know a lot about. What are the good and bad points to having a dry sump in your OFF-ROAD vehicle?

jowlz · Post by **jowlz** » Sat Oct 28, 2006 9:08 am

Good=

No oil sloshing around up and on the crankshaft=loss of power
You can make the reservoir as large as you want
More ground clearance

Bad=

More moving parts
More weight..depending on how large your reservoir is.

I'm sure there are more good and bads...but the good definately out weighs the bad. I am all for using a dry sump system when possible.

scott the viking · Post by **scott the viking** » Sat Oct 28, 2006 9:52 am

I personally run a dry sump on everything I can...one of the bigger downfalls in my opinion is price...to do it right is not cheap. As said by jowls...the biggy is windage...meaning...your crank running in liquid robs power... In example....take two men that run the exact same speed...and set up a race between them...put one on dry land and the other in waist deep water, start the race. No comparison really.

The other is that no matter how steep of a hill you are on...you will still have oil feeding the engine. A sump will do this too...but...if you roll the car on it's side...it will lose oil pressure with a sump...not really a big concern for carbureted engine because they will usually die in a roll...but an FI engine will just keep purring along with no oil pressure even when on it's side. Trust me when I tell you that you normally don't shut the car off the very first thing after rolling...you sit there stunned for a few seconds first...and that is all it take for an engine with no pressure to eat itself.

A dry sump is not what I would call "necessary" by any means...but..I would call it a good thing if you have it.

72bajaben · Post by **72bajaben** » Sat Oct 28, 2006 2:40 pm

whats involved in putting one in? are there kits. i really dont know anything about dry sumps. i have heard of them, but didnt really pay any attention.

Hot Wheels · Post by **Hot Wheels** » Sat Oct 28, 2006 2:46 pm

plus

Larger volume of oil so it cirulates less often.
Cools the oil more as its in the tank

Minus

complex to set up right your first time
Finding a place for that tank...

I bought my motor ruined by an improper dry sump hookup. The bypass was wrong and it lost pressuer as the engine warmed up. took me more than a week of research, questions etc... to figure out how to do it right when i re-built the motor.

takotruckin · Post by **takotruckin** » Sat Oct 28, 2006 5:23 pm

i would like to run one for ground clearance...

72bajaben · Post by **72bajaben** » Sat Oct 28, 2006 5:49 pm

where are you guys looking at to get one of these?

scott the viking · Post by **scott the viking** » Sat Oct 28, 2006 6:02 pm

72bajaben wrote:where are you guys looking at to get one of these?

I personally do not know where you can buy a dry sump for an air cooled engine as a "kit" I am sure someone must make one though...Mine is made up from different pieces...I made the oil tank...and all the lines/fittings...If I remember correctly...I bought the oil pump from aircooled.net...but may be mistaken.

72bajaben · Post by **72bajaben** » Sat Oct 28, 2006 6:50 pm

well scott since you have one, can you explain how it works then?

Post by **Leatherneck** » Sat Oct 28, 2006 7:37 pm

Yes Scott, please do.

scott the viking · Post by **scott the viking** » Sat Oct 28, 2006 8:14 pm

Magic

I will in a bit...

scott the viking · Post by **scott the viking** » Sat Oct 28, 2006 8:27 pm

Okay...this is really pretty simple. I assume everyone here has a basic idea of how a wet sump system works. In a dry sump system...the oil for the oil pump to feed the motor comes from a container on the outside of the engine. So...oil gets pulled from the container....pushed through the engine...then a second oil pump sucks the oil out of the engine and puts it back in the container so it can make another run through the motor. The idea being to have the very minimum of oil needed inside the engine.

Marty · Post by **Marty** » Sat Oct 28, 2006 9:16 pm

Thats a pretty good explanation. You can also get additional benifits using a multi-stage pump and scavanging from different areas of the motor.
I custom build dry sump systems too.
The MAIN benefit of a dry sump system in my mind is the bearinga are MUCH "happier". The oil is less aireated and you tend to have a much greater volume of oil flowing throw a dry sump pump over a conventional wet sump pump. You are also "sucking" oil externally from a tank that tends to have enough volume in it to keep the pump from cavitating and ever sucking any air.
The VW wet sump pump CAN suck air from inside the case and is very prone to cavitation. It works, but a dry sump system is 10 times better IMO.

Tank and dry sump system in a drag car I built.

72bajaben · Post by **72bajaben** » Sun Oct 29, 2006 12:37 am

holy man that looks complicated.

bajaherbie · Post by **bajaherbie** » Sun Oct 29, 2006 4:45 am

marty, is that one of those 1641 "big bore kits"?

on a serious note, how much oil does it hold?

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