Wet Sump vs. Dry Sump [Archive] - Yamaha R1 Forum: YZF-R1 Forums

: Wet Sump vs. Dry Sump


Loudpipe
09-28-2009, 01:46 PM
Why are all modern sport bikes wet sump designs, as opposed to dry sump? Seems like dry sumps (which are used in high performance and racings cars) would be the more "stable" way to lubricate a high performance engine, especially one whose attitude (leaning left/right) changes quite a lot. Don't have to worry about the crank getting bogged down in the oil, or whipping it into a froth, thus creating a problem with oil pressure. Even my old CB750 had a dry sump system.

iceman4357
09-28-2009, 02:01 PM
...especially when they put the sump at the FRONT of the damn engine which can cause the engine to starve for oil.

turd1
09-28-2009, 06:49 PM
it probably involves cost and room/design.

Loudpipe
09-28-2009, 07:14 PM
it probably involves cost and room/design.

I don't think so. The MotoGP bikes use a wet sump as well, and cost isn't a problem for them. Gotta be another reason.

Loudpipe
09-28-2009, 09:15 PM
But MotoGP bike teams don't really have a budget.

That's the whole point. If a dy sump system is better, than surely a MotoGP bike would run it, regardless of cost.

yankin&bankin
10-02-2009, 11:01 AM
Why are all modern sport bikes wet sump designs, as opposed to dry sump? Seems like dry sumps (which are used in high performance and racings cars) would be the more "stable" way to lubricate a high performance engine, especially one whose attitude (leaning left/right) changes quite a lot. Don't have to worry about the crank getting bogged down in the oil, or whipping it into a froth, thus creating a problem with oil pressure. Even my old CB750 had a dry sump system.


ALL modern sport bikes DO NOT use wet-sump oiling, as you infer.:fact

Most Aprilia motorcycles use dry-sump oiling, as well as the KTM Super Duke and 1190 RC-8.

Other sportbikes, the names of which you would recognize, use dry-sump oiling systems - I just can't think of any more examples right now.

I would agree with Blu that the reason is probably cost...the Japanese OEMs are trying to maintain a certain price point in their bikes as one of the ways to differentiate them from the European bikes.

A hallmark of Jap bikes has always been the ability to equal or exceed the performance of Euro bikes, at a lower price of admission. Part of the reason they are able to do this is by limiting unnecessary gadgets on the bikes (such as dry-sump oiling).

Yes, dry-sump offers some advantages, such as lower weight and consistent oiling in high-G cornering, but it's really not needed - these bikes do fine with wet-sump.

Loudpipe
10-02-2009, 01:01 PM
ALL modern sport bikes DO NOT use wet-sump oiling, as you infer.:fact

I know that not all modern sport bikes use wet-sump designs. That was a generalization.

I can only imagine that the Big Four have gotten wet-sump designs to be "good enough" where they don't think the added complexity of a dry sump is necessary. I still don't think cost is an issue in their decision, because the MotoGP bikes use a wet-sump design (unless the regulations require that and the manufacturers don't have a choice... I don't know).

sss r1
10-02-2009, 01:54 PM
I don't think so. The MotoGP bikes use a wet sump as well, and cost isn't a problem for them. Gotta be another reason.
motogp bikes use dry sump .

Loudpipe
10-02-2009, 02:40 PM
motogp bikes use dry sump .

No, they don't. They're all wet sump.

sss r1
10-02-2009, 03:08 PM
No, they don't. They're all wet sump.
ok , coz u said so :dundun:

honda rcv :
"Another unique aspect of the engine was its semi-dry-sump oiling system; the crankshaft area is sealed off as a separate chamber, and a scavenge pump uses the transmission cavity as an oil reservoir. This setup offers numerous benefits over conventional wet- and dry-sump designs, including less pumping losses and blow-by into the combustion chamber, a more stable oil level and a stronger and more compact crankcase construction."

http://www.sportrider.com/features/0704_sprp_2005_honda_rc211v/index.html


i think ducati is also dry sump , but i cant find it.

kawasaki , yami and suzuki are all wet sump , because they are using conventional il4 engine config.

conventional il4 engine is wide , so it must be installed high in the chasis (for ground clearance mainly) .this leaves lots of space and simplicity for regular wet sump.

all other engine configurations (v2,v4,v5) installed lower in the frame , so they use dry sump most of the time.

Loudpipe
10-02-2009, 03:16 PM
ok , coz u said so :dundun:

honda rcv :
"Another unique aspect of the engine was its semi-dry-sump oiling system; the crankshaft area is sealed off as a separate chamber, and a scavenge pump uses the transmission cavity as an oil reservoir. This setup offers numerous benefits over conventional wet- and dry-sump designs, including less pumping losses and blow-by into the combustion chamber, a more stable oil level and a stronger and more compact crankcase construction."

http://www.sportrider.com/features/0704_sprp_2005_honda_rc211v/index.html


i think ducati is also dry sump , but i cant find it.

kawasaki , yami and suzuki are all wet sump , because they are using conventional il4 engine config.

conventional il4 engine is wide , so it must be installed high in the chasis (for ground clearance mainly) .this leaves lots of space and simplicity for regular wet sump.

all other engine configurations (v2,v4,v5) installed lower in the frame , so they use dry sump most of the time.

So I'm right. Thanks for proving my point. Dry-sump is only used out of necessity (clearance), not because it's better in some way. Sounds like Honda is the only one that has a proprietary system, and even that is not strictly dry-sump.

sss r1
10-02-2009, 03:32 PM
also , motrcycles are a bit different fron cars . motorcycles lean into the turn , so , the oil wont move to the outer side of the engine .
if that was the case , motorcycle would never work good with carburetors.
take a carbed bike , lean it 45 deg while standing still , the engine will stall.
luckily , this doesnt happen when u ride :)

or , take a cup with water , hold it in your hand and spin around ...:crash
now do the same thing , but lean the cup into the turning radius ... see what i mean?

Loudpipe
10-02-2009, 03:37 PM
also , motrcycles are a bit different fron cars . motorcycles lean into the turn , so , the oil wont move to the outer side of the engine .
if that was the case , motorcycle would never work good with carburetors.
take a carbed bike , lean it 45 deg while standing still , the engine will stall.
luckily , this doesnt happen when u ride :)

or , take a cup with water , hold it in your hand and spin around ...:crash
now do the same thing , but lean the cup into the turning radius ... see what i mean?

That's a good point. The oil probably doesn't slosh around quite as much as in a car because of the centripetal force.