Re: Tech Question: Why no dry sump in production vehicles?

["Rich Wagner" <drsavage@domain.elided>]

Jess wrote:

>I know that the dry sump design allows engine to sit lower (no oil sump
>to raise the engine) so the CG of the car canbe lower -> better handling.
>The forced lubrication to me means all the important part of engine are
>properly lubricated even under heavy cornering

Even with a dry sump system, the same delivery pump and oil galleries are
used, so dry sump offers no advantage in actual lubrication.  However, with
a dry sump system, a scavenge pump, with a higher pump rate than the
delivery pump, must also reside in the engine's sump.  The major advantages
to dry sump systems are that the engine can be made much shorter; the oil
tank can be located in some convenient location;  the oil tank can be made
to deliver in any attitude or under any type of acceleration, which is
important for airplanes and race cars, where oil delivery can be
interrupted under adverse conditions; and adding an oil cooler is a trivial
task.

Dry sump systems are much more expensive to produce than wet sump systems,
since extra hardware is required, and since, because of the way engines are
designed and made, a wet sump system almost comes for free.

Honda made a number of motorcycles with dry sump systems.  They were
popular models that were built back in the '70's.


Rich Wagner
Montrose, CO
'82 GTV6 Balocco

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