Wet Sump or Dry Sump?

[scandelous]

What is the difference between a wet sump and a dry sump #6 drive and motors?

[Chris]

The technical difference is that on the wet sump, the gears run fully immersed in oil. On a dry sump, oil is injected at the gears contact point and then suctioned from below and into a holding tank. The real-world advantage is you lose the drag associated with turning the gears in a very viscous fluid. That equates to a decent amount of "found" horsepower.

As has been said before, when you get to a certain point, a dry 6 is the cheapest 50 to 75 horsepower you can ever find. That point is probably around 1k/HP.

[scandelous]

The technical difference is that on the wet sump, the gears run fully immersed in oil. On a dry sump, oil is injected at the gears contact point and then suctioned from below and into a holding tank. The real-world advantage is you lose the drag associated with turning the gears in a very viscous fluid. That equates to a decent amount of "found" horsepower.

As has been said before, when you get to a certain point, a dry 6 is the cheapest 50 to 75 horsepower you can ever find. That point is probably around 1k/HP.

Chris, Does the same apply with engine power also?

[Chris]

Not exactly. With an engine, what you're trying to avoid is oil on the crankshaft and reciprocating assembly. You would think that it would be like a tire- as soon as it turn, the centrifugal force would spin the fluid off. But oil in an engine actually looks like a rope as it's being pulled along with the crank. Good windage trays, crank scrapers and other devices are good at keeping it off and having a dry sump adds to that. But not dramatically. In some cases, racers are changing to roller cam bearings to keep the oil down and also ducting the top end oil outside and around the reciprocating assembly and directly into the pan. Dry sump scavenging the top end makes that even more effective.

The real benefit of a dry sump system is in the volume and consistency of supply. Volume helps because as the oil is returned to the dry sump tank, it has a brief opportunity to settle and de-aerate. You also don't have the concern of exposing to pan pickup and pumping air to your bearings- something that can and does happen in a wet sump engine in a boat being tossed hard.

[BraceYourself]

If you can affoard it, you want drysump. Less hp loss.

[scandelous]

Chris, Are there any maintenance issues I should be cognoscente about?

[Chris]

With which one?

I guess the answer on either is not really. One BIG advantage of the dry 6 vs. the wet is the dry uses a fraction of the lube that the wet one does. That can save you major $$. The dry sump engine is going to mean some more hardware in the bilge but it uses the same oil, although a bit more, and the same filters. I would make sure to keep an eye on the drive belt. But they're cheap.

[OldSchool]

With which one?

I guess the answer on either is not really. One BIG advantage of the dry 6 vs. the wet is the dry uses a fraction of the lube that the wet one does. That can save you major $$. The dry sump engine is going to mean some more hardware in the bilge but it uses the same oil, although a bit more, and the same filters. I would make sure to keep an eye on the drive belt. But they're cheap.

I'll vouch for that one!! My drives (wet-sump#6's) hold 4.5 gallons of fluid each! Dry sumps hold 4 quarts...or something like that.

But I don't have to worry about clogged screens or failing pumps!!

[scandelous]

Ok, are the pumps mechanical or electric?

[2112]

Gilmer belt off the crank, usually.