Dry Sump??

[jack d]

I have seen the Tenere engine referred to as a dry sump engine on this forum. I see no separate oil tank, no oil in the frame, no sump extension below the engine and there does not seem to be a scavenge oil pump to return oil to the sump. It looks like every other engine that has a wet sump. Is there something I am missing?

 

[magic]

The oil tank is built into the crankcase. Hence the need for 2 drain plugs as the oil pan is divided into 2 reservoirs. This design only uses 1 oil pump. You're not missing anything, take a look at an exploded view of the engine it will all make sense. Rocky Mountain ATV has exploded views in their OEM parts section. Checking your oil level can be somewhat interesting as the level in the sight glass seems to change, but don't worry about it too much. Just dump in the 3.6 quarts or so when you change oil and forget about it. I check mine according to the owner's manual and have not seen any oil consumption yet.

 

[EricV]

@magic - Very nice explanation. ::008:: you nailed it.

 

[jack d]

Thanks for the explanation however I am familiar with this type of design and have no problems with my bike. I was curious as to why people refer to this as a dry sump when it is not.

 

[Sierra1]

My tech described it to me as a "semi-dry" sump. I don't know/care what it means; it obviously works well. I did notice a definite color difference in the oil drained from the front tank vs the rear tank. My tech also told me it adds a step to the oil change; no sweat. ::001::

 

[EricV]

Thanks for the explanation however I am familiar with this type of design and have no problems with my bike. I was curious as to why people refer to this as a dry sump when it is not.

Hmm, then you should be able to understand the description above. It is a dry sump, it's just not a stand alone design with a mechanically separate reservoir. The engine only has a quart or so of oil in it at any one time. The oil pump draws oil from the separate reservoir, pumps it thru the engine and back to the reservoir. There is no wet sump at the bottom of the engine with any significant volume of oil present and rods skimming thru it with wipers, etc.

If you don't feel it's a dry sump design, what type do you believe it to be?

The lack of an external reservoir, (aircraft or older HD, for example), does not preclude it from being a dry sump. The two drain plugs are part of the giveaway to the nature of the design. Another is the sight glass and very specific nature of the oil level check routine in the owner's manual.

 

[jack d]

I finally did find a diagram of the oiling system and saw that there are 2 separate oil pumps in the oil pump assembly. The feed pump pulls oil from the rear section of the crankcase and supplies the engine and transmission. Oil drains from the engine and transmission into both the front and rear sections of the bottom of the engine. The rear section is considered the oil tank while the front is what would be called the dry sump as the scavenge pump pulls oil from there to keep it "dry" and returns that oil to the rear section or tank. So yes it is a dry sump engine. Thanks for the comments.

 

[jack d]

So after debating this and researching on the internet I happened upon a different thread pertaining to oil level and there was some very detailed explanations of the oil system and the unique dry sump of the Tenere. Should have done a forum search before posting.

 

[Checkswrecks]

No problem and this thread was probably enlightening to a few others.

 

[Paletes3]

Try these videos, they explain the S10 dry sump system:

https://youtu.be/rb5yq46IHmo

https://youtu.be/eE3JiG2ni18

 

[jack d]

Thanks, a picture is worth a thousand words.