scootz
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| posted on 4/10/11 at 06:40 PM |
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Dry Sumps & Negative Engine Pressure
In general terms... would a dry-sumped engine need gaskets???
It's Evolution Baby!
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steve m
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| posted on 4/10/11 at 06:49 PM |
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Without a head gasket, it would be a pain to start !
or, perhaps i should dry sump my xflow, as it leaks every were, and get rid of all my gaskets!
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britishtrident
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| posted on 4/10/11 at 07:10 PM |
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Only if you didn't want it to p*** oil every where ----- think ancient Triumph motorcycle dry sump but still p****d oil out.
As far as I know the only practical way to get a proper sub atmospheric in a normal four stroke sump is to connect the crankcase breather to a
venturi on the exhaust --- which is outlawed both on track and road.
[Edited on 4/10/11 by britishtrident]
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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scootz
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| posted on 4/10/11 at 07:34 PM |
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Cheers guys.. it was just a piece written by Al Melling that got me thinking...
The race engine has a dry sump engine and was designed for full racing in a Single Seater Race car that is why the Pumps are down the side as in
Formula one Cars/Engines. The high capacity Oil Scavenge Pump is also on the Formula One principle and makes the internal pressure of the engine a
negative. The advantage of this is that the engine does not have any Gaskets and allows for accurate fitment of the components without oil leaks.
It's Evolution Baby!
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matt_gsxr
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| posted on 4/10/11 at 07:46 PM |
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If you search on "crankcase vacuum" you will see its a popular topic and many claim it achievable with dry sump systems.
You get more power as the pumping loses in the engine are reduced.
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britishtrident
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| posted on 4/10/11 at 07:48 PM |
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No oil pump can really be big enough to get worthwhile negative pressure in the sump, as for getting rid of gaskets many modern engines are
gasketless they just use a tiny thickness of the appropriate Loctite sealant grade (nb not ordinary RTV Instant Gasket) on the mating faces.
The main object in reducing crankcase pressure is power (reduced crankshaft & piston windage losses) and improved piston ring sealing.
A few years a Formula Ford 1600 racer put a venturi into the exhaust of his Xflo and connected it to the crankcase breathe, he gained a few
horsepower but the device was deemed illegal as it wassn't a closed loop breather and hence deposits oil on the track and following cars.
[Edited on 4/10/11 by britishtrident]
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SeanStone
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| posted on 4/10/11 at 10:36 PM |
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It is very possible to pull a decent vacuum from a dry sump pump. I forget the figures quoted now but one of my lecturers design engine for scumacher
and alonso's last 2 championship engines and it featured heavily in the dry sump lectures. Probably in my notes somewhere!
Yes it would need gasgets
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