Wildguzzi.com
General Category => General Discussion => Topic started by: Littlefield on March 20, 2026, 08:47:51 AM
-
Just curious. The dry sump is vented to the crankcase, yes? Must be something more than just a hole that separates the 2.
How is this done? Does a high level in the sump result in oil blowback into the inlet air?
-
If it helps, here’s a photo of a V85TT engine from underneath (so you’re looking up into the sump ceiling):
(https://i.ibb.co/9322fstX/IMG-9667.png) (https://ibb.co/9322fstX)
And here are pics of the engine looking down from above:
(https://i.ibb.co/MkjHKRtW/IMG-9670.png) (https://ibb.co/MkjHKRtW) (https://i.ibb.co/CKDYxZz8/IMG-9672.png) (https://ibb.co/CKDYxZz8) (https://i.ibb.co/zH5Nq98h/IMG-9669.png) (https://ibb.co/zH5Nq98h)
More pics of the engine at the following eBay link:
https://ebay.us/m/Fs7K0p (https://ebay.us/m/Fs7K0p)
-
I think it's called a simi dry sump and no over filling doesn't blow it out like on early v7 serries.
-
It is a wet sump with a floor in the crankcase. A dry sump would be just that and an oil tank mounted to supply oil. You can do the same on a bigblock with a sheet metal plate between pan & block.
-
It is a wet sump with a floor in the crankcase. A dry sump would be just that and an oil tank mounted to supply oil. You can do the same on a bigblock with a sheet metal plate between pan & block.
I believe Guzzi refers to it as a semi-dry sump system because it isn't JUST the same as a big block with a windage plate. Unlike the other Guzzis with which most of us are aware I'm reading that the V85 uses dual oil pumps, one for oil feed and one for recovery (just like a remote oil tank dry sump might).
-
It is a wet sump with a floor in the crankcase. A dry sump would be just that and an oil tank mounted to supply oil. You can do the same on a bigblock with a sheet metal plate between pan & block.
My understanding—and feel free to correct me—is that the defining characteristic of a wet sump is that the internals are dipped in the oil bath to a degree as they move, whereas a dry sump means none of the internals are dipping as they rotate. A wet sump causes windage, if I’m using the term correctly, which keeps the crank, cam, etc. from spinning as fast those in a dry sump.
-
If the site glass shows the level in the sump, not the crankcase, and the only way oil gets into the sump is by the scavenger pump, no drain hole, it’s hard to imagine how the sump oil level rises when the engine shits off.
-
If the site glass shows the level in the sump, not the crankcase, and the only way oil gets into the sump is by the scavenger pump, no drain hole, it’s hard to imagine how the sump oil level rises when the engine shits off.
I wouldn't assume the return pump is the "only" way. There may be drain back that takes time and isn't a factor when the motor is running.
But I don't have a V85 so I have no experience with how much and how fast the level rises.