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What is the difference betwen the wet sump and dry sump ??/ any BIG dissadvantage ??

Pwrbt33

iTrader: (2)

A dry sump takes less HP to turn and holds a lot less oil. Dry sumps also have a filter you should change every year as well and the wet sumps do not.

LubeJobs42

iTrader: (2)

The skeg also make a difference especially on cats. I had wet sumps on the Motion. Over 150 I would loose steering due to the shape of the skeg. hen I changed to dry sumps with the sept back skeg, the boat handled like a different boat. Hord to believe something so minuscule can make such a big difference!!

fountainguy214

i dont even think that they still make the wet stumps....do they??????

bouyhunter

The very little I understand of it...
The dry sump puts more of a spray of oil where it is needed, the wet sump slops it all over the place to make sure everything is covered.
Too much oil actually "sludges" the drive instead of just lubricating, slowing it down because it's losing power by pushing oil instead of using it to lubricate.
I don't mean "sludging" by thickening the oil, but more, wasting HP to draw a puddle of oil to cover everything, vs. spray to cover the vital parts only, and not the items that don't need a bath.

HUSTLEthis

Hey Todd.....what boat are you looking at....

both drives have the same gears, bearings and shafts...
wet sumps hold approx 4 gals of oil..
dry sumps hold approx 1 gal of oil....however the Merc "dry sump" isn't a true dry sump because it holds the gal of oil in the lower unit (submersing the lower unit gears and bearings)... the oil is then pumped and sprayed on the upper gears and bearings by a pump that is in the lower unit.
It is more efficient than a wet sump, but not as efficient as a true dry sump like PatW (Shifter on OSO ) installs. He is the expert.
Ours are wet sump with the Hering skegs....I don't think the horsepower loss is that much more compared to the Merc dry sumps because we run full synthetic oil...but I could be wrong...
If you think about it your Bravo's are wet sump drives....

cougarman

Wetsumps as mentioned are about 4 gallons of oil and are completly full of oil. So All your gears, bearing's and shafts are getting a full oil bath. Takes more power to turn all that oil cause you are constantly fighting the resistance of the oil.

I can't remember the exact number but I thought Pat W. said you drop well over 100 degree's in drive temperature too, when you switch from the wetsump to the drysump. This is running temp at speed.

Herring Skeg is nice for speed and handling. I have been told by all the major #6 shops until your running 120 mph it's not even needed. Other's argue at 100 MPH it's noticable.
I don't have to worry about either with my big ole pig.

Also told depending on if you have a Cat or a V-bottom there are speed increases of up to 3 mph. 7XChamp said they only picked up 1 mph on the APACHE HERITAGE race boat.
Told depending on your speeds and RPM's you can pick up 50 to 80 HP.

Mercury runs about 2 1/2 gallons of oil in there drysump.
The lower half holds the oil and there is a pump in the nose cone that pumps the oil to the top and sprays the top half of the drives.

Pat W. Full drysump has the pump in the upper housing and runs scavage lines to the bottom to keep it dry. Oil is pumped to a tank inside the boat and then returned to spray the drives.
Pat Sold the mercury conversions to Vern Gilbert also in California.

I have 3 #6 wetsumps available that will be in OSO classifieds shortly . RH and LH ( 1.61 ) and a RH ( 1.5 )

Jon

BraceYourself

I've been told the wet sump 6's have less problems. More oil in the drive means if you neglect the frequent oil change the more oil in the drive the better.

Why are 6's RH or LH? Couldn't the prop determine that.

tanner

Tom, Extreme powerboats has a 38 gun with Cobra power and # 6's, just was thinking of looking at tit someday. Just don't know about the Cobra power .

Lucky Strike Jr

I heard that boat can be bought right too.