2 replies to this topic

[lancelot]

hi i'm nicolas from france
i fitted a rotary morgo oil pump on my ariel ht5.
the problem is that when i run it, i only see oil and air bulbs slowly exiting in the return hose...shouldn't the flow be airless and continuous?no wet sumping i think, because i do not see smoke at all, and the tank level looks the same...
what could be the problem? when i unscrew the priming bolt, it leaks oil with no bulbs
i'm afraid of the feed line...
what do you think about that?
cheers
nicolas

[Stork955]

Gday, that is OK. The return part of the pump is larger than the feed, so it always trys to remove more oil than is put in by the feed side of the pump. A few air bubbles means that it is working OK, no return at all is a problem!

Cheers,


Stork

[Tayld]

Hi there,
A dry sump engine with a separate oil tank has in effect two oil pumps generally combined into one unit. The feed pump has a lower capacity than the return pump. This is to make sure the sump in the engine is always emptied. Because the bigger return pump can always pump more oil than the feed pump the return into the tank is often seen as a mixture of oil and air. This is quite normal for an engine when both the feed and return pumps are working properly.
The original plunger pump would have had two sizes of plunger, the bigger diameter plunger is the return or scavenge plunger.
Hope this helps.