Dry sump engine oil change - Any refilling precautions?

Merry Christmas to you Art

I am 97.8% certain that when you fill the reservoir the sump first fills up. To test this theory, just leave the sump's drain plug off and then start filling the reservoir. If oil starts coming out of the sump's drain plug then you know it is reaching the sump. Let us know what you find out.

Ivan

 

On a dry sump engine, the oil in the sump is scavanged and pumped back to the tank. The oil "pressure" pump is fed directly from the tank, so filling the tank will assure an immediate supply of oil to the pressure pump when the engine is started. If you had a way to add oil to the sump, when the engine is started, it would just be pumped back to the tank by the scavenge pumps.

 

I really don't know the technical stuff, but have been changing dry sump oils for 14+ years on my Quattroporte, Gransport and Z06 and you basically fill from the reservoir, 100+ track days later on the Z06 and, 150k miles later on 3 different Maseratis, knock on wood, no problems!

 

Art: When the motor is shut off, over time, some oil will drain back through the piping and work its way through the scavenge pumps to the sump. This process is referred to as "wet sumping". This is the reason you need to check the tank oil level immediately after shutting the engine off. It is just the opposite of checking the oil in a wet sump car, when you want to let all the oil drain down into the sump, With the dry sump engines, you want to see the level BEFORE any oil has begun to slowly drain out of the tank. Checking the oil tank level when cold can sometimes lead to adding more oil and overfilling the entire system.

 

Another related thought is to spin the engine up on the starter with no plugs to get oil pressure through the motor, then refit the plugs and start (I think this was originally an Ivan trick). I do this after the car has been sitting for an extended period.