Dry sump lubrication
Discussion
I have been reading some of the posts about oil level etc can anyone out there explain exactly how the dry sump works and perhaps point me in the direction of a diagram or two I think I know the basics but would like to know for sure. >>> Edited by zazwaldo on Friday 26th March 20:46
Normally you would have a sump that contains most of the oil in the engine. There is a pump that sits in or feeds oil directly from the sump to the engine. This is all well and good but all that oil is in there sloshing around as you go over bumps, round corners etc. In extreme conditions this leads to oil surge which you would probably notice as fluctuating oil pressure.
In a dry sump engine most of the oil is contained in a tank outside of the engine block. The pump draws oil from that tank and feeds it to the engine. The oil passes trough the components of the engine then finds its way back to the lowest point where there is a collection chamber and a scavenging pump which recirculates the oil back into the external tank. In this system there is very little oil sloshing around in the sump and the system is effectively immune to surge.
Hope that make some sense......
In a dry sump engine most of the oil is contained in a tank outside of the engine block. The pump draws oil from that tank and feeds it to the engine. The oil passes trough the components of the engine then finds its way back to the lowest point where there is a collection chamber and a scavenging pump which recirculates the oil back into the external tank. In this system there is very little oil sloshing around in the sump and the system is effectively immune to surge.
Hope that make some sense......
VYT, I couldn't have writtin it better!
One can see the carter (holds the oil), sitting at the bottom of the engine , usually slightly sloped to one point. Take a look at a naked Ducati, or under your TVR. In case of the Duc, it has a little round window to show you the oil level.
As mentioned earlier, the primary goal was to keep (race-)engines lubricated under high G-force corners, pulling away and braking. (In that case, the oil was always drawn to one side of the engine!)
Hope VYT was of any help, as I can't do it more properly!
One can see the carter (holds the oil), sitting at the bottom of the engine , usually slightly sloped to one point. Take a look at a naked Ducati, or under your TVR. In case of the Duc, it has a little round window to show you the oil level.
As mentioned earlier, the primary goal was to keep (race-)engines lubricated under high G-force corners, pulling away and braking. (In that case, the oil was always drawn to one side of the engine!)
Hope VYT was of any help, as I can't do it more properly!
This is a picture of a Ducati Monster, where you can clearly see the forward facing cylinder, clutch and under the clutch, the carter, which is the basis of the dry sump lubrification. between the clutch and the carter, you can see the small little round window where you can check the oil level.
[pic] www.ducati.com/docs_eng/photogalleries2/MS4R_04/images/f11.jpg [/pic]
So the lowest part of the engine block is the carter. Check out the two black cables (start low at one of the oil pumps), which distribute the oil to each of the two cylinders in this engine.
Hope this is of any use.
Edited to put another piccie on, two cables no longer visible in this pic.
>> Edited by Waveboy14 on Monday 29th March 20:48
>> Edited by Waveboy14 on Monday 29th March 20:49
[pic] www.ducati.com/docs_eng/photogalleries2/MS4R_04/images/f11.jpg [/pic]
So the lowest part of the engine block is the carter. Check out the two black cables (start low at one of the oil pumps), which distribute the oil to each of the two cylinders in this engine.
Hope this is of any use.
Edited to put another piccie on, two cables no longer visible in this pic.
>> Edited by Waveboy14 on Monday 29th March 20:48
>> Edited by Waveboy14 on Monday 29th March 20:49
bertie said:
It also reduces the power losses due to windage as the big ends drag through the oil during cornering and thus also stops the oil aeration this causes.
Bertie, this is not actually correct.... a dry sump pan means there is less volume under the crank shaft and hence there is not much room for the crank case to breath as the pistons compress the air. It is possible to loose upto 20BHP if the bottom doesn't breathe properly. It all depends on how much room there is unfer the crankshaft.... at work we have done this on a dry sumped engine, and by lowering the sump by 100mm, managed to release a further 15-20BHP.
>> Edited by matt_c on Monday 29th March 20:44
matt_c said:
Bertie, this is not actually correct.... a dry sump pan means there is less volume under the crank shaft and hence there is not much room for the crank case to breath as the pistons compress the air. It is possible to loose upto 20BHP if the bottom doesn't breathe properly. It all depends on how much room there is unfer the crankshaft.... at work we have done this on a dry sumped engine, and by lowering the sump by 100mm, managed to release a further 15-20BHP.
I agree Matt. Doesn't it have to do with vacuum building up, which counteracts the oil pumps (not being able anymore to "push" oil)? This is not present in case of a good dry sump design.
matt_c said:
Bertie, this is not actually correct.... a dry sump pan means there is less volume under the crank shaft and hence there is not much room for the crank case to breath as the pistons compress the air. It is possible to loose upto 20BHP if the bottom doesn't breathe properly. It all depends on how much room there is unfer the crankshaft.... at work we have done this on a dry sumped engine, and by lowering the sump by 100mm, managed to release a further 15-20BHP.
Fair enough, it rings a bell now you say it, but now I'm slightly confused?????
So are you saying a shallow dry sump setup looses power compared to a deep sump?
Also, surely if the oild can slosh enough to miss the pump pick up, it must get caught by the big ends??
Just when you think you've got it.......
How can you tell in that case how much oil you have before you start the engine surely its possible for there to be no oil in catch tank after a lengthy lay up how dfo you know if its due to genuine low oil level or just oil settling back into crankcase. The reason I ask is that I work away from home a lot and have just realised I've been checking my level wrong since I got the car. Why isn't there a one way valve fitted to stop the oil flowing back?
You have to check the oil level immediately after switching off the engine to get a correct level.
If you've been checking it without running the engine first you will have overfilled rather than underfilled it.
It settles back until it all reaches the same level, I've no idea if they do or indeed why they don't have a one way valve on the scavenge pump outlet, but even if they do you couldn't rely on a one way valve big enough to allow enough flow to seal perfectly for many months.
If you've been checking it without running the engine first you will have overfilled rather than underfilled it.
It settles back until it all reaches the same level, I've no idea if they do or indeed why they don't have a one way valve on the scavenge pump outlet, but even if they do you couldn't rely on a one way valve big enough to allow enough flow to seal perfectly for many months.
I don't know about installing a valve, but I think that would very much have to do with having to install more than one valve (complexity), or significantly heightening the engine, which would result in a higher center of gravity (not wanted in race engines).
About your Ducati, nice choice! Red I presume? Doesn't your duke have a warning light on the dashboard?
About your Ducati, nice choice! Red I presume? Doesn't your duke have a warning light on the dashboard?
Most definitely not red!!!! Really wanted a yellow one since for about 2 years now but started looking around Nov last year and found what I believe to be a limited edition titanium with red wheels it and my Tuscan are my babies. I know sad git!!!!!! No warning light just a sight window on side of engine.
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